Data Types

Numeric Types

CUBRID supports the following numeric data types to store integers or real numbers.

Type Bytes Min Max Exact/approx.
SHORT, SMALLINT 2 -32,768 32,767 exact numeric
INTEGER, INT 4 -2,147,483,648 +2,147,483,647 exact numeric
BIGINT 8 -9,223,372,036,854,775,808 +9,223,372,036,854,775,807 exact numeric
NUMERIC, DECIMAL 16

precision p: 1

scale s: 0

precision p: 38

scale s: 38

exact numeric
FLOAT, REAL 4 -3.402823466E+38 (ANSI/IEEE 754-1985 standard) +3.402823466E+38 (ANSI/IEEE 754-1985 standard) approximate numeric floating point : 7
DOUBLE, DOUBLE PRECISION 8 -1.7976931348623157E+308 (ANSI/IEEE 754-1985 standard) +1.7976931348623157E+308 (ANSI/IEEE 754-1985 standard) approximate numeric floating point : 15

Numeric data types are divided into exact and approximate types. Exact numeric data types (SMALLINT, INT, BIGINT, NUMERIC) are used for numbers whose values must be precise and consistent, such as the numbers used in financial accounting. Note that even when the literal values are equal, approximate numeric data types (FLOAT, DOUBLE) can be interpreted differently depending on the system.

CUBRID does not support the UNSIGNED type for numeric data types.

On the above table, two types on the same cell are identical types but it always prints the above type name when you execute SHOW COLUMNS statement. For example, you can use both SHORT and SMALLINT when you create a table, but it prints “SHORT” when you execute SHOW COLUMNS statement.

Precision and Scale

The precision of numeric data types is defined as the number of significant figures. This applies to both exact and approximate numeric data types.

The scale represents the number of digits following the decimal point. It is significant only in exact numeric data types. Attributes declared as exact numeric data types always have fixed precision and scale. NUMERIC (or DECIMAL) data type always has at least one-digit precision, and the scale should be between 0 and the precision declared. Scale cannot be greater than precision. For INTEGER, SMALLINT, or BIGINT data types, the scale is 0 (i.e. no digits following the decimal point), and the precision is fixed by the system.

Numeric Literals

Special signs can be used to input numeric values. The plus sign (+) and minus sign (-) are used to represent positive and negative numbers respectively. You can also use scientific notations. In addition, you can use currency signs specified in the system to represent currency values. The maximum precision that can be expressed by a numeric literal is 255.

Numeric Coercions

All numeric data type values can be compared with each other. To do this, automatic coercion to the common numeric data type is performed. For explicit coercion, use the CAST operator. When different data types are sorted or calculated in a numerical expression, the system performs automatic coercion. For example, when adding a FLOAT attribute value to an INTEGER attribute value, the system automatically coerces the INTEGER value to the most approximate FLOAT value before it performs the addition operation.

The following is an example to print out the value of FLOAT type when adding the value of INTEGER type to the value of FLOAT type.

CREATE TABLE tbl (a INT, b FLOAT);
INSERT INTO tbl VALUES (10, 5.5);
SELECT a + b FROM tbl;
1.550000e+01

This is an example of overflow error occurred when adding two integer values, the following can be an INTEGER type value for the result.

SELECT 100000000*1000000;
ERROR: Data overflow on data type integer.

In the above case, if you specify one of two integers as the BIGINT type, it will determine the result value into the BIGINT type, and then output the normal result.

SELECT CAST(100000000 AS BIGINT)*1000000;
100000000000000

Warning

Earlier version than CUBRID 2008 R2.0, the input constant value exceeds INTEGER, it is handled as NUMERIC. However, 2008 R2.0 or later versions, it is handled as BIGINT .

INT/INTEGER

The INTEGER data type is used to represent integers. The value range is available is from -2,147,483,648 to +2,147,483,647. SMALLINT is used for small integers, and BIGINT is used for big integers.

  • If a real number is entered for an INT type, the number is rounded to zero decimal place and the integer value is stored.
  • INTEGER and INT are used interchangeably.
  • DEFAULT constraint can be specified in a column of this type.
If you specify 8934 as INTEGER, 8934 is stored.
If you specify 7823467 as INTEGER, 7823467 is stored.
If you specify 89.8 to an INTEGER, 90 is stored (all digits after the decimal point are rounded).
If you specify 3458901122 as INTEGER, an error occurs (if the allowable limit is exceeded).

SHORT/SMALLINT

The SMALLINT data type is used to represent a small integer type. The value range is available is from -32,768 to +32,767.

  • If a real number is entered for an SMALLINT type, the number is rounded to zero decimal place and the integer value is stored.
  • SMALLINT and SHORT are used interchangeably.
  • DEFAULT constraint can be specified in a column of this type.
If you specify 8934 as SMALLINT, 8934 is stored.
If you specify 34.5 as SMALLINT, 35 is stored (all digits after the decimal point are rounded).
If you specify 23467 as SMALLINT, 23467 is stored.
If you specify 89354 as SMALLINT, an error occurs (if the allowable limit is exceeded).

BIGINT

The BIGINT data type is used to represent big integers. The value range is available from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.

  • If a real number is entered for a BIG type, the number is rounded to zero decimal place and the integer value is stored.

  • Based on the precision and the range of representation, the following order is applied.

    SMALLINT ??**INTEGER** ??**BIGINT** ??**NUMERIC**

  • DEFAULT constraint can be specified in a column of this type.

If you specify 8934 as BIGINT, 8934 is stored.
If you specify 89.1 as BIGINT, 89 is stored.
If you specify 89.8 as BIGINT, 90 is stored (all digits after the decimal point are rounded).
If you specify 3458901122 as BIGINT, 3458901122 is stored.

NUMERIC/DECIMAL

NUMERIC or DECIMAL data types are used to represent fixed-point numbers. As an option, the total number of digits (precision) and the number of digits after the decimal point (scale) can be specified for definition. The minimum value for the precision p is 1. When the precision p is omitted, you cannot enter data whose integer part exceeds 15 digits because the default value is 15. If the scale s is omitted, an integer rounded to the first digit after the decimal point is returned because the default value is 0.

NUMERIC [(p[, s])]
  • Precision must be equal to or greater than scale.
  • Precision must be equal to or greater than the number of integer digits + scale.
  • NUMERIC, DECIMAL, and DEC are used interchangeably.
  • To check how the precision and the scale became changed when you operate with NUMERIC typed values, see Arithmetic Operations and Type Casting of Numeric Data Types.
  • DEFAULT constraint can be specified in a column of this type.
If you specify 12345.6789 as NUMERIC, 12346 is stored (it rounds to the first place after the decimal point since 0 is the default value of scale).
If you specify 12345.6789 as NUMERIC(4), an error occurs (precision must be equal to or greater than the number of integer digits).
If you declare NUMERIC(3,4), an error occurs (precision must be equal to or greater than the scale).
If you specify 0.12345678 as NUMERIC(4,4), .1235 is stored (it rounds to the fifth place after the decimal point).
If you specify -0.123456789 as NUMERIC(4,4), -.1235 is stored (it rounds to the fifth place after decimal point and then prefixes a minus (-) sign).

FLOAT/REAL

The FLOAT (or REAL) data type represents floating point numbers.

The ranges of values that can be described as normalized values are from -3.402823466E+38 to -1.175494351E-38, 0, and from +1.175494351E-38 to +3.402823466E+38, whereas the values other than normalized values, which are closer to 0, are described as de-normalized values. It conforms to the ANSI/IEEE 754-1985 standard.

The minimum value for the precision p is 1 and the maximum value is 38. When the precision p is omitted or it is specified as seven or less, it is represented as single precision (in 7 significant figures). If the precision p is greater than 7 and equal to or less than 38, it is represented as double precision (in 15 significant figures) and it is converted into DOUBLE data type.

FLOAT data types must not be used if you want to store a precise value that exceeds the number of significant figures, as they only store the approximate value of any input value over 7 significant figures.

FLOAT[(p)]
  • FLOAT is in 7 significant figures.
  • Extra cautions are required when comparing data because the FLOAT type stores approximate numeric.
  • FLOAT and REAL are used interchangeably.
  • DEFAULT constraint can be specified in a column of this type.
If you specify 16777217 as FLOAT, 16777216 is stored and 1.677722e+07 is displayed (if precision is omitted, 8-th digit is rounded up because it is represented as 7 significant figures).
If you specify 16777217 as FLOAT(5), 16777216 is stored and 1.677722e+07 is displayed (if precision is in seven or less, 8-th digit is rounded up because it is represented as 7 significant figures).
If you specify 16777.217 as FLOAT(5), 16777.216 is stored and 1.677722e+04 is displayed (if precision is in seven or less, 8-th digit is rounded up because it is represented as 7 significant figures).
If you specify 16777.217 as FLOAT(10), 16777.217 is stored and 1.677721700000000e+04 is displayed (if precision is greater than 7 and less than or equal to 38, zeroes are added because it is represented as 15 significant figures).

DOUBLE/DOUBLE PRECISION

The DOUBLE data type is used to represent floating point numbers.

The ranges of values that can be described as normalized values are from -1.7976931348623157E+308 to -2.2250738585072014E-308, 0, and from 2.2250738585072014E-308 to 1.7976931348623157E+308, whereas the values other than normalized values, which are closer to 0, are described as de-normalized values. It conforms to the ANSI/IEEE 754-1985 standard.

The precision p is not specified. The data specified as this data type is represented as double precision (in 15 significant figures).

DOUBLE data types must not be used if you want to store a precise value that exceeds the number of significant figures, as they only store the approximate value of any input value over 15 significant figures.

  • DOUBLE is in 15 significant figures.
  • Extra caution is required when comparing data because the DOUBLE type stores approximate numeric.
  • DOUBLE and DOUBLE PRECISION are used interchangeably.
  • DEFAULT constraint can be specified in a column of this type.
If you specify 1234.56789 as DOUBLE, 1234.56789 is stored and 1.234567890000000e+03 is displayed.
If you specify 9007199254740993 as DOUBLE, 9007199254740992 is stored and 9.007199254740992e+15 is displayed.

Note

MONETARY type is deprecated, and it is not recommended anymore.

Date/Time Types

Date/time data types are used to represent the date or time (or both together). CUBRID supports the following data types:

Type bytes Min. Max. Note
DATE 4 0001-01-01 9999-12-31 As an exception, DATE ‘0000-00-00’ format is allowed.
TIME 4 00:00:00 23:59:59  
TIMESTAMP 4 1970-01-01 00:00:01 (GMT) 1970-01-01 09:00:01 (KST) 2038-01-19 03:14:07 (GMT) 2038-01-19 12:14:07 (KST) As an exception, TIMESTAMP ‘0000-00-00 00:00:00’ format is allowed.
DATETIME 8 0001-01-01 00:00:0.000 9999-12-31 23:59:59.999 As an exception, DATETIME ‘0000-00-00 00:00:00’ format is allowed.
TIMESTAMPLTZ 4 Depends on timezone 1970-01-01 00:00:01 (GMT) Depends on timezone 2038-01-19 03:14:07 (GMT) Timestamp with local timezone. As an exception, TIMESTAMPLTZ’0000-00-00 00:00:00’ format is allowed.
TIMESTAMPTZ 8 Depends on timezone 1970-01-01 00:00:01 (GMT) Depends on timezone 2038-01-19 03:14:07 (GMT) Timestamp with timezone. As an exception, TIMESTAMPTZ ‘0000-00-00 00:00:00’ format is allowed.
DATETIMELTZ 8 Depends on timezone 0001-01-01 00:00:0.000 UTC Depends on timezone 9999-12-31 23:59:59.999 Datetime with local timezone. As an exception, DATETIMELTZ ‘0000-00-00 00:00:00’ format is allowed.
DATETIMETZ 12 Depends on timezone 0001-01-01 00:00:0.000 UTC Depends on timezone 9999-12-31 23:59:59.999 Datetime with timezone. As an exception, DATETIMETZ ‘0000-00-00 00:00:00’ format is allowed.

Range and Resolution

  • By default, the range of a time value is represented by the 24-hour system. Dates follow the Gregorian calendar. An error occurs if a value that does not meet these two constraints is entered as a date or time.
  • The range of year in DATE is 0001 - 9999 AD.
  • From the CUBRID 2008 R3.0 version, if time value is represented with two-digit numbers, a number from 00 to 69 is converted into a number from 2000 to 2069; a number from 70 to 99 is converted into a number from 1970 to 1999. In earlier than CUBRID 2008 R3.0 version, if time value is represented with two-digit numbers, a number from 01 to 99 is converted into a number from 0001 to 0099.
  • The range of TIMESTAMP is between 1970-01-01 00:00:01 and 2038-01-19 03 03:14:07 (GMT). For KST (GMT+9), values from 1970-01-01 09:00:01 to 2038-01-19 12:14:07 can be stored. timestamp’1970-01-01 00:00:00’ (GMT) is the same as timestamp’0000-00-00 00:00:00’.
  • The range of TIMESTAMPLTZ, TIMESTAMPTZ varies with timezone, but the value converted to UTC should be between 1970-01-01 00:00:01 and 2038-01-19 03 03:14:07.
  • The range of DATETIMELTZ, DATETIMETZ varies with timezone, but the value converted to UTC should be between 0001-01-01 00:00:0.000 and 9999-12-31 23:59:59.999. A value stored in database may no longer be valid if session timezone changes.
  • The results of date, time and timestamp operations may depend on the rounding mode. In these cases, for Time and Timestamp, the most approximate second is used as the minimum resolution; for Date, the most approximate date is used as the minimum resolution.

Coercions

The Date / Time types can be cast explicitly using the CAST operator only when they have the same field. For implicit coercion, see Implicit Type Conversion. The following table shows types that allows explicit coercions. For implicit coercion, see Arithmetic Operations and Type Casting of DATE/TIME Data Types.

Explicit Coercions

FROM \ TO DATE TIME DATETIME TIMESTAMP
DATE - X O O
TIME X - X X
DATETIME O O - O
TIMESTAMP O O O -

In general, zero is not allowed in DATE, DATETIME, and TIMESTAMP types. However, if both date and time values are 0, it is allowed as an exception. This is useful in terms that this value can be used if an index exists upon query execution of a column corresponding to the type.

  • Some functions in which the DATE, DATETIME, and TIMESTAMP types are specified as an argument return different value based on the return_null_on_function_errors system parameter if every input argument value for date and time is 0. If return_null_on_function_errors is yes, NULL is returned; if no, an error is returned. The default value is no.
  • The functions that return DATE, DATETIME, and TIMESTAMP types can return a value of 0 for date and time. However, these values cannot be stored in Date objects in Java applications. Therefore, it will be processed with one of the following based on the configuration of zeroDateTimeBehavior, the connection URL property: being handled as an exception, returning NULL, or returning a minimum value (see Configuration Connection).
  • If the intl_date_lang system is configured, input string of TO_DATE(), TO_TIME(), TO_DATETIME(), TO_TIMESTAMP(), DATE_FORMAT(), TIME_FORMAT(), TO_CHAR() and STR_TO_DATE() functions follows the corresponding locale date format. For details, see Statement/Type-Related Parameters and the description of each function.
  • Types with timezone follow the same conversion rules as their parent type.

Note

For literals of date/time types and date/time types with timezone, see Date/Time.

DATE

The DATE data type is used to represent the year (yyyy), month (mm) and day (dd). Supported range is “01/01/0001” to “12/31/9999.” The year can be omitted. If it is, the year value of the current system is specified automatically. The specified input/output types are as follows:

date'mm/dd[/yyyy]'
date'[yyyy-]mm-dd'
  • All fields must be entered as integer.
  • The date value is displayed in the type of ‘MM/DD/YYYY’ in CSQL, and it is displayed in the type of ‘YYYY-MM-DD’ in JDBC application programs and the CUBRID Manager.
  • The TO_DATE() function is used to convert a character string type into a DATE type.
  • 0 is not allowed to input in year, month, and day; however, ‘0000-00-00’, which every digit consisting of year, month, and day is 0, is allowed as an exception.
  • DEFAULT constraint can be specified in a column of this type.
DATE'2008-10-31' is displayed as '10/31/2008'.
DATE'10/31' is displayed as '10/31/2011'(if a value for year is omitted, the current year is automatically specified).
DATE'00-10-31' is displayed as '10/31/2000'.
DATE'0000-10-31' is displayed as an error (a year value should be at least 1).
DATE'70-10-31' is displayed as '10/31/1970'.
DATE'0070-10-31' is displayed as '10/31/0070'.

TIME

The TIME data type is used to represent the hour (hh), minute (mm) and second (ss). Supported range is “00:00:00” to “23:59:59.” Second can be omitted; if it is, 0 seconds is specified. Both 12-hour and 24-hour notations are allowed as an input format. The input format of TIME is as follows:

time'hh:mi[:ss] [am | pm]'
  • All items must be entered as integer.
  • AM/PM time notation is used to display time in the CSQL; while the 24-hour notation is used in the CUBRID Manager.
  • AM/PM can be specified in the 24-hour notation. An error occurs if the time specified does not follow the AM/PM format.
  • Every time value is stored in the 24-hour notation.
  • The TO_TIME() function is used to return a character string type into a TIME type.
  • DEFAULT constraint can be specified in a column of this type.
TIME'00:00:00' is outputted as '12:00:00 AM'.
TIME'1:15' is regarded as '01:15:00 AM'.
TIME'13:15:45' is regarded as '01:15:45 PM'.
TIME'13:15:45 pm' is stored normally.
TIME'13:15:45 am' is an error (an input value does not match the AM/PM format).

TIMESTAMP

The TIMESTAMP data type is used to represent a data value in which the date (year, month, date) and time (hour, minute, second) are combined. The range of representable value is between GMT ‘1970-01-01 00:00:01’ and ‘2038-01-19 03:14:07’. The DATETIME type can be used if the value is out of range or data in milliseconds is stored. The input format of TIMESTAMP is as follows:

timestamp'hh:mi[:ss] [am|pm] mm/dd[/yyyy]'
timestamp'hh:mi[:ss] [am|pm] [yyyy-]mm-dd'

timestamp'mm/dd[/yyyy] hh:mi[:ss] [am|pm]'
timestamp'[yyyy-]mm-dd hh:mi[:ss] [am|pm]'
  • All fields must be entered in integer format.
  • If the year is omitted, the current year is specified by default. If the time value (hour/minute/second) is omitted, 12:00:00 AM is specified.
  • You can store the timestamp value of the system in the TIMESTAMP type by using the SYS_TIMESTAMP(or SYSTIMESTAMP, CURRENT_TIMESTAMP).
  • The TIMESTAMP() or TO_TIMESTAMP() function is used to cast a character string type into a TIMESTAMP type.
  • 0 is not allowed to input in year, month, and day; however, ‘0000-00-00 00:00:00’, which every digit consisting of year, month, day, hour, minute, and second is 0, is allowed as an exception. GMT timestamp’1970-01-01 12:00:00 AM’ or KST timestamp’1970-01-01 09:00:00 AM’ is translated into timestamp’0000-00-00 00:00:00’.
  • DEFAULT constraint can be specified in a column of this type.
TIMESTAMP'10/31' is outputted as '12:00:00 AM 10/31/2011' (if the value for year/time is omitted, a default value is outputted ).
TIMESTAMP'10/31/2008' is outputted as '12:00:00 AM 10/31/2008' (if the value for time is omitted, a default value is outputted ).
TIMESTAMP'13:15:45 10/31/2008' is outputted as '01:15:45 PM 10/31/2008'.
TIMESTAMP'01:15:45 PM 2008-10-31' is outputted as '01:15:45 PM 10/31/2008'.
TIMESTAMP'13:15:45 2008-10-31' is outputted as '01:15:45 PM 10/31/2008'.
TIMESTAMP'10/31/2008 01:15:45 PM' is outputted as '01:15:45 PM 10/31/2008'.
TIMESTAMP'10/31/2008 13:15:45' is outputted as '01:15:45 PM 10/31/2008'.
TIMESTAMP'2008-10-31 01:15:45 PM' is outputted as '01:15:45 PM 10/31/2008'.
TIMESTAMP'2008-10-31 13:15:45' is outputted as '01:15:45 PM 10/31/2008'.
An error occurs on TIMESTAMP '2099-10-31 01:15:45 PM' (out of range to represent TIMESTAMP).

DATETIME

The DATETIME data type is used to represent a data value in which the data (year, month, date) and time (hour, minute, second) are combined. The range of representable value is between 0001-01-01 00:00:00.000 and 9999-12-31 23:59:59.999 (GMT). The input format of TIMESTAMP is as follows:

datetime'hh:mi[:ss[.msec]] [am|pm] mm/dd[/yyyy]'
datetime'hh:mi[:ss[.msec]] [am|pm] [yyyy-]mm-dd'
datetime'mm/dd[/yyyy] hh:mi[:ss[.ff]] [am|pm]'
datetime'[yyyy-]mm-dd hh:mi[:ss[.ff]] [am|pm]'
  • All fields must be entered as integer.
  • If you year is omitted, the current year is specified by default. If the value (hour, minute/second) is omitted, 12:00:00.000 AM is specified.
  • You can store the timestamp value of the system in the DATETIME type by using the SYS_DATETIME (or SYSDATETIME, CURRENT_DATETIME, CURRENT_DATETIME(), NOW()) function.
  • The TO_DATETIME() function is used to convert a string type into a DATETIME type.
  • 0 is not allowed to input in year, month, and day; however, ‘0000-00-00 00:00:00’, which every digit consisting of year, month, day, hour, minute, and second is 0, is allowed as an exception.
  • DEFAULT constraint can be specified in a column of this type.
DATETIME'10/31' is outputted as '12:00:00.000 AM 10/31/2011' (if the value for year/time is omitted, a default value is outputted).
DATETIME'10/31/2008' is outputted as '12:00:00.000 AM 10/31/2008'.
DATETIME'13:15:45 10/31/2008' is outputted as '01:15:45.000 PM 10/31/2008'.
DATETIME'01:15:45 PM 2008-10-31' is outputted as '01:15:45.000 PM 10/31/2008'.
DATETIME'13:15:45 2008-10-31' is outputted as '01:15:45.000 PM 10/31/2008'.
DATETIME'10/31/2008 01:15:45 PM' is outputted as '01:15:45.000 PM 10/31/2008'.
DATETIME'10/31/2008 13:15:45' is outputted as '01:15:45.000 PM 10/31/2008'.
DATETIME'2008-10-31 01:15:45 PM' is outputted as '01:15:45.000 PM 10/31/2008'.
DATETIME'2008-10-31 13:15:45' is outputted as '01:15:45.000 PM 10/31/2008'.
DATETIME'2099-10-31 01:15:45 PM' is outputted as '01:15:45.000 PM 10/31/2099'.

CASTing a String to Date/Time Type

Available Format for Strings in Date/Time Type

CAST() function allows the below format for date/time strings.

Available DATE String Format

[year sep] month sep day
  • 2011-04-20: April 20th, 2011
  • 04-20: April 20th of this year

If a separator (sep) is a slash (/), strings are recognized in the following order:

month/day[/year]
  • 04/20/2011: April 20th, 2011
  • 04/20: April 20th of this year

If you do not use a separator (sep), strings are recognized in the following format. It is allowed to use 1, 2, and 4 digits for years and 1 and 2 digits for months. For day, you should always enter 2 digits.

YYYYMMDD
YYMMDD
YMMDD
MMDD
MDD
  • 20110420: April 20th, 2011
  • 110420: April 20th, 2011
  • 420: April 20th of this year

Available TIME String Format

[hour]:min[:[sec]][.[msec]] [am|pm]
  • 09:10:15.359 am: 9 hours 10 minutes 15 seconds AM (0.359 seconds will be truncated)
  • 09:10:15: 9 hours 10 minutes 15 seconds AM
  • 09:10: 9 hours 10 minutes AM
  • :10: 12 hours 10 minutes AM
[[[[[[Y]Y]Y]Y]M]MDD]HHMISS[.[msec]] [am|pm]
  • 20110420091015.359 am: 9 hours 10 minutes 15 seconds AM
  • 0420091015: 9 hours 10 minutes 15 seconds AM
[H]HMMSS[.[msec]] [am|pm]
  • 091015.359 am: 9 hours 10 minutes 15 seconds AM
  • 91015: 9 hours 10 minutes 15 seconds AM
[M]MSS[.[msec]] [am|pm]
  • 1015.359 am: 12 hours 10 minutes 15 seconds AM
  • 1015: 12 hours 10 minutes 15 seconds AM
[S]S[.[msec]] [am|pm]
  • 15.359 am: 12 hours 15 seconds AM
  • 15: 12 hours 15 seconds AM

Note

: The [H]H format was allowed in CUBRID 2008 R3.1 and the earlier versions. That is, the string ‘10’ was converted to TIME ‘10:00:00’ in the R3.1 and the earlier versions, and will be converted to TIME ‘00:00:10’ in version R4.0 and later.

Available DATETIME String Format

[year sep] month sep day [sep] [sep] hour [sep min[sep sec[.[msec]]]]
  • 04-20 09: April 20th of this year, 9 hours AM
month/day[/year] [sep] hour [sep min [sep sec[.[msec]]]]
  • 04/20 09: April 20th of this year, 9 hours AM
year sep month sep day sep hour [sep min[sep sec[.[msec]]]]
  • 2011-04-20 09: April 20th, 2011, 9 hours AM
month/day/year sep hour [sep min[sep sec [.[msec]]]]
  • 04/20/2011 09: April 20th, 2011, 9 hours AM
YYMMDDH (It is allowed only when time format is one digit.)
  • 1104209: April 20th, 2011, 9 hours AM
YYMMDDHHMI[SS[.msec]]
  • 1104200910.359: April 20th, 2011, 9 hours 10 minutes AM (0.359 seconds will be truncated)
  • 110420091000.359: April 20th, 2011, 9 hours 10 minutes 0.359 seconds AM
YYYYMMDDHHMISS[.msec]
  • 201104200910.359: November 4th, 2020 8 hours 9 minutes 10.359 seconds PM
  • 20110420091000.359: April 20th, 2011, 9 hours 10 minutes 0.359 seconds AM

Available Time-Date String Format

[hour]:min[:sec[.msec]] [am|pm] [year-]month-day
  • 09:10:15.359 am 2011-04-20: April 20th, 2011, 9 hours 10 minutes 15.359 seconds AM
  • :10 04-20: April 20th of this year, 12 hours 10 minutes AM
[hour]:min[:sec[.msec]] [am|pm] month/day[/[year]]
  • 09:10:15.359 am 04/20/2011: April 20th, 2011, 9 hours 10 minutes 15.359 seconds AM
  • :10 04/20: April 20th of this year, 12 hours 10 minutes AM
hour[:min[:sec[.[msec]]]] [am|pm] [year-]month-day
  • 09:10:15.359 am 04-20: April 20th of this year, 9 hours 10 minutes 15.359 seconds AM
  • 09 04-20: April 20th of this year, 9 hours AM
hour[:min[:sec[.[msec]]]] [am|pm] month/day[/[year]]
  • 09:10:15.359 am 04/20: April 20th of this year, 9 hours 10 minutes, 15.359 seconds AM
  • 09 04/20: April 20th of this year, 9 hours AM

Rules

msec is a series of numbers representing milliseconds. The numbers after the fourth digit will be ignored. The rules for the separator string are as follows:

  • You should always use one colon (:) as a separator for the TIME separator.
  • DATE and DATETIME strings can be represented as a series of numbers without the separator sep), and non-alphanumeric characters can be used as separators. The DATETIME string can be divided into Time and Date with a space.
  • Separators should be identical in the input string.
  • For the Time-Date string, you can only use colon (:) for a Time separator and hyphen (-) or slash (/) for a Date separator. If you use a hyphen when entering date, you should enter like yyyy-mm-dd; in case of a slash, enter like mm/dd/yyyy.

The following rules will be applied in the part of date.

  • You can omit the year as long as the syntax allows it.
  • If you enter the year as two digits, it represents the range from 1970-2069. That is, if YY<70, it is treated as 2000+YY; if YY>=70, it is treated as 1900+YY. If you enter one, three or four digit numbers for the year, the numbers will be represented as they are.
  • A space before and after a string and the string next to the space are ignored. The am/pm identifier for the DATETIME and TIME strings can be recognized as part of TIME value, but are not recognized as the am/pm identifier if non-space characters are added to it.

The TIMESTAMP type of CUBRID consists of DATE type and TIME type, and DATETIME type consists of DATE type and TIME type with milliseconds being added to them. Input strings can include Date (DATE string), Time (TIME string), or both (DATETIME strings). You can convert a string including a specific type of data to another type, and the following rules will be applied for the conversion.

  • If you convert the DATE string to the DATETIME type, the time value will be ‘00:00:00.’
  • If you convert the TIME string to the DATETIME type, colon (:) is recognized as a date separator, so that the TIME string can be recognized as a date string and the time value will be ‘00:00:00.’
  • If you convert the DATETIME string to the DATE type, the time part will be ignored from the result but the time input value format should be valid.
  • You can covert the DATETIME string to the TIME type, and you must follow the following rules.
    • The date and time in the string must be divided by at least one blank.
    • The date part of the result value is ignored but the date input value format should be valid.
    • The year in the date part must be over 4 digits (available to start with 0) or the time part must include hours and minutes ([H]H:[M]M) at least. Otherwise the date pate are recognized as the TIME type of the [MM]SS format, and the following string will be ignored.
  • If the one of the units (year, month, date, hour, minute and second) of the DATETIME string is greater than 999999, it is not recognized as a number, so the string including the corresponding unit will be ignored. For example, in ‘2009-10-21 20:9943:10’, an error occurs because the value in minutes is out of the range. However, if ‘2009-10-21 20:1000123:10’ is entered,’2009’ is recognized as the TIME type of the MMSS format, so that TIME ‘00:20:09’ will be returned.
  • If you convert the time-date sting to the TIME type, the date part of the string is ignored but the date part format must be valid.
  • All input strings including the time part allow [.msec] on conversion, but only the DATETIME type can be maintained. If you convert this to a type such as DATE, TIMESTAMP or TIME, the msec value is discarded.
  • All conversions in the DATETIME, TIME string allow English locale following after time value or am/pm specifier written in the current locale of a server.
SELECT CAST('420' AS DATE);
   cast('420' as date)
======================
  04/20/2012
SELECT CAST('91015' AS TIME);
   cast('91015' as time)
========================
  09:10:15 AM
SELECT CAST('110420091035.359' AS DATETIME);
   cast('110420091035.359' as datetime)
=======================================
  09:10:35.359 AM 04/20/2011
SELECT CAST('110420091035.359' AS TIMESTAMP);
   cast('110420091035.359' as timestamp)
========================================
  09:10:35 AM 04/20/2011

Date/Time Types with Timezone

Date/Time types with timezone are date/time types which can be input or output by specifying timezone. There are two ways of specifying timezone; specifying the name of local zone and specifying the offset of time.

Timezone information are considered in the Date/Time types if TZ or LTZ is followed after the existing Date/Time types; TZ means timezone, and LTZ means local timezone.

  • TZ type can be represented as <date/time type> WITH TIME ZONE. This stores UTC time and timezone information (decided by a user or session timezone) when this is created. TZ type requires 4 bytes more to store timezone information.
  • LTZ type can be represented as <date/time type> WITH LOCAL TIME ZONE. This stores UTC time internally; when this value is output, this is converted as a value of a local (current session) time zone.

This table describes date/time types to compare date/time types with timezone together.

UTC in the table means Coordinated Universal Time.

Category Type Input Store Output Description
DATE DATE Without timezone Input value Absolute (the same as input) Date
DATETIME DATETIME Without timezone Input value Absolute (the same as input) Date/time including milliseconds
DATETIMETZ With timezone UTC + timezone(region or offset) Absolute (keep input timezone) Date/time + timezone
DATETIMELTZ With timezone UTC Relative (transformed by session timezone) Date/time in the session timezone
TIME TIME Without timezone Input value Absolute (the same as input) Time
TIMESTAMP TIMESTAMP Without timezone UTC Relative (transformed by session timezone) Input value is translated as a session timezone’s value.
TIMESTAMPTZ With timezone UTC + timezone(region or offset) Absolute (keep input timezone) UTC + timestamp with timezone
TIMESTAMPLTZ With timezone UTC Relative (transformed by session timezone) Session timezone. Same as TIMESTAMP’s value, but timezone specifier is output when this is printed out.

The other features of date/time types with timezone (e.g. maximum/minimum value, range, resolution) are the same with the features of general date/time types.

Note

  • On CUBRID, TIMESTAMP is stored as second unit, after Jan. 1, 1970 UTC (UNIX epoch).
  • Some DBMS’s TIMESTAMP is similar to CUBRID’s DATETIME as the respect of saving milliseconds.

To see examples of functions using timezone types, see Date/Time Functions and Operators.

The following shows that the output values are different among DATETIME, DATETIMETZ and DATETIMELTZ when session timezone is changed.

--  csql> ;set timezone="+09"

CREATE TABLE tbl (a DATETIME, b DATETIMETZ,  c DATETIMELTZ);
INSERT INTO tbl VALUES (datetime'2015-02-24 12:30', datetimetz'2015-02-24 12:30', datetimeltz'2015-02-24 12:30');

SELECT * FROM tbl;
12:30:00.000 PM 02/24/2015     12:30:00.000 PM 02/24/2015 +09:00                12:30:00.000 PM 02/24/2015 +09:00
-- csql> ;set timezone="+07"

SELECT * FROM tbl;
12:30:00.000 PM 02/24/2015     12:30:00.000 PM 02/24/2015 +09:00                10:30:00.000 AM 02/24/2015 +07:00

The following shows that the output values are different among TIMESTAMP, TIMESTAMPTZ and TIMESTAMPLTZ when session timezone is changed.

-- ;set timezone="+09"

CREATE TABLE tbl (a TIMESTAMP, b TIMESTAMPTZ,  c TIMESTAMPLTZ);
INSERT INTO tbl VALUES (timestamp'2015-02-24 12:30', timestamptz'2015-02-24 12:30', timestampltz'2015-02-24 12:30');

SELECT * FROM tbl;
12:30:00 PM 02/24/2015     12:30:00 PM 02/24/2015 +09:00                12:30:00 PM 02/24/2015 +09:00
-- csql> ;set timezone="+07"

SELECT * FROM tbl;
10:30:00 AM 02/24/2015     12:30:00 PM 02/24/2015 +09:00                10:30:00 AM 02/24/2015 +07:00

Conversion from string to timestamp types

Conversion from string to timestamp/timestampltz/timestamptz are performed in context for creating timestamp objects from literals.

From/to Timestamp Timestampltz Timestamptz
String (without timezone) Interpret the date/time parts in session timezone. Convert to UTC, encode and store the Unix epoch. Interpret the date/time parts in session timezone. Convert to UTC, encode and store the Unix epoch. Interpret the date/time parts in session timezone. Convert to UTC, encode and store the Unix epoch and TZ_ID of session
String (with timezone) Error (timezone part is not supported for timestamp). Convert from value’s timezone to UTC. Encode and store the Unix epoch. Convert from value’s timezone to UTC. Encode and store the Unix epoch and TZ_ID of value’s timezone.

Conversion from string to datetime types

Conversion from string to datetime/datetimeltz/datetimetz are performed in context for creating datetime objects from literals.

From/to Datetime Datetimeltz Datetimetz
String (without timezone) Store the parsed values from string. Interpret the date/time parts in session timezone. Convert to UTC and store the new values. Interpret the date/time parts in session timezone. Convert to UTC and store the new values and TZ_ID of session
String (with timezone) Error (timezone part is not supported for datetime). Convert from value’s timezone to UTC. Store the new values in UTC reference. Convert from value’s timezone to UTC. Store the new values in UTC reference TZ_ID of string’s timezone.

Conversion of datetime and timestamp types to string (printing of values)

From/to String (timezone printing not allowed) String (timezone force print) String (no requirement for timezone - free choice)
TIMESTAMP Decode Unix epoch to session timezone and print Decode Unix epoch to session timezone and print with session timezone. Decode Unix epoch to session timezone and print. Do not print timezone string
TIMESTAMPLTZ Decode Unix epoch to session timezone and print Decode Unix epoch to session timezone and print with session timezone. Decode Unix epoch to session timezone and print. Print session timezone.
TIMESTAMPTZ Decode Unix epoch to timezone from value and print it. Decode Unix epoch to timezone from value and print it; print timezone from value. Decode Unix epoch to timezone from value and print it; print timezone from value.
DATETIME Print the stored values. Print the stored value and session timezone. Print the stored value. Do not print any timezone.
DATETIMELTZ Convert from UTC to session timezone and print the new value. Convert from UTC to session timezone and print it. Print session timezone Convert from UTC to session timezone and print it. Print session timezone.
DATETIMELTZ Convert from UTC to value’s timezone and print the new value. Convert from UTC to value’s timezone and print it. Print value’s timezone Convert from UTC to value’s timezone and print it. Print value’s timezone.

Timezone Configuration

The below shows the timezone related parameters configured in cubrid.conf. For parameter’s configuration, see cubrid.conf Configuration File and Default Parameters.

  • timezone

    Specifies a timezone for a session. The default is a value of server_timezone.

  • server_timezone

    Specifies a timezone for a server. The default is a timezone of OS.

  • tz_leap_second_support

    Sets for support for leap second as yes or no. The default is no.

Timezone Function

The following are timezone related functions. For each function’s detail usage, click each function’s name.

Functions with a Timezone Type

All functions which use DATETIME, TIMESTAMP or TIME typed value in their input value, can use timezone typed value.

The below is an example of using timezone typed values, it works the same as the case without timezone. Exceptionally, if the type name ends with LTZ, the output value of this type follows the local timezone’s setting (timezone parameter).

On the below example, the default unit of a number is millisecond, which is the minimum unit of DATETIME type.

SELECT datetimeltz '09/01/2009 03:30:30 pm' + 1;
03:30:30.001 PM 09/01/2009 Asia/Seoul
SELECT datetimeltz '09/01/2009 03:30:30 pm' - 1;
03:30:29.999 PM 09/01/2009 Asia/Seoul

On the below example, the default unit of a number is second, which is the minimum unit of TIMESTAMP type.

SELECT timestamptz '09/01/2009 03:30:30 pm' + 1;
03:30:31 PM 09/01/2009 Asia/Seoul
SELECT timestamptz '09/01/2009 03:30:30 pm' - 1;
03:30:29 PM 09/01/2009 Asia/Seoul
SELECT EXTRACT (hour from datetimetz'10/15/1986 5:45:15.135 am Europe/Bucharest');

5

A type which the name ends with LTZ follows the setting of local timezone. Therefore, if the value of timezone parameter is set to ‘Asia/Seoul’, EXTRACT function returns hour value of this timezone.

-- csql> ;set timezone='Asia/Seoul'

SELECT EXTRACT (hour from datetimeltz'10/15/1986 5:45:15.135 am Europe/Bucharest');
12

Conversion Functions for Timezone Types

The following are functions converting a string to a date/time typed value, or date/time typed value to a string; The value can include an information like an offset, a zone and a daylight saving.

For each function’s usage, see the each function’s explanation by clicking the function name.

SELECT DATE_FORMAT (datetimetz'2012-02-02 10:10:10 Europe/Zurich CET', '%TZR %TZD %TZH %TZM');
SELECT STR_TO_DATE ('2001-10-11 02:03:04 AM Europe/Bucharest EEST', '%Y-%m-%d %h:%i:%s %p %TZR %TZD');
SELECT TO_CHAR (datetimetz'2001-10-11 02:03:04 AM Europe/Bucharest EEST');
SELECT TO_DATETIME_TZ ('2001-10-11 02:03:04 AM Europe/Bucharest EEST');
SELECT TO_TIMESTAMP_TZ ('2001-10-11 02:03:04 AM Europe/Bucharest');

Note

TO_TIMESTAMP_TZ() and TO_DATETIME_TZ() functions do the same behaviors with TO_TIMESTAMP() and TO_DATETIME() functions except that they can have TZR, TZD, TZH and TZM information in their date/time argument.

CUBRID uses the region name of timezone in the IANA(Internet Assigned Numbers Authority) timezone database region; for IANA timezone, see http://www.iana.org/time-zones.

IANA Timezone

In IANA(Internet Assigned Numbers Authority) timezone database, there are lots of codes and data which represent the history of localtime for many representative locations around the globe.

This database is periodically updated to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules. Its management procedure is described in BCP 175: Procedures for Maintaining the Time Zone Database. For more details, see http://www.iana.org/time-zones.

CUBRID supports IANA timezone, and a user can use the IANA timezone library in the CUBRID installation package as it is. If you want to update as the recent timezone, update timezone first, compile timezone library, and restart the database.

Regarding this, see Compiling Timezone Library.

Bit Strings

A bit string is a sequence of bits (1’s and 0’s). Images (bitmaps) displayed on the computer screen can be stored as bit strings. CUBRID supports the following two types of bit strings:

  • Fixed-length bit string (BIT)
  • Variable-length bit string (BIT VARYING)

A bit string can be used as a method argument or an attribute type. Bit string literals are represented in a binary or hexadecimal format. For binary format, append the string consisting of 0’s and 1’s to the letter B or append a value to the 0b as shown example below.

B'1010'
0b1010

For hexadecimal format, append the string consisting of the numbers 0 - 9 and the letters A - F to the uppercase letter X or append a value to the 0x . The following is hexadecimal representation of the same number that was represented above in binary format.

X'a'
0xA

The letters used in hexadecimal numbers are not case-sensitive. That is, X’4f’ and X’4F’ are considered as the same value.

Length

If a bit string is used in table attributes or method declarations, you must specify the maximum length. The maximum length for a bit string is 1,073,741,823 bits.

Bit String Coercion

Automatic coercion is performed between a fixed-length and a variable-length bit string for comparison. For explicit coercion, use the CAST() operator.

BIT(n)

Fixed-length binary or hexadecimal bit strings are represented as BIT (n), where n is the maximum number of bits. If n is not specified, the length is set to 1. If n is not specified, the length is set to 1. The bit string is filled with 8-bit unit from the left side. For example, the value of B’1’ is the same as the value of B’10000000’. Therefore, it is recommended to declare a length by 8-bit unit, and input a value by 8-bit unit.

Note

If you input B’1’ to the BIT(4) column, it is printed out X’8’ on CSQL, X’80’ on CUBRID Manager or application program.

  • n must be a number greater than 0.
  • If the length of the string exceeds n, it is truncated and filled with 0s.
  • If a bit string smaller than n is stored, the remainder of the string is filled with 0s.
  • DEFAULT constraint can be specified in a column of this type.
CREATE TABLE bit_tbl(a1 BIT, a2 BIT(1), a3 BIT(8), a4 BIT VARYING);
INSERT INTO bit_tbl VALUES (B'1', B'1', B'1', B'1');
INSERT INTO bit_tbl VALUES (0b1, 0b1, 0b1, 0b1);
INSERT INTO bit_tbl(a3,a4) VALUES (B'1010', B'1010');
INSERT INTO bit_tbl(a3,a4) VALUES (0xaa, 0xaa);
SELECT * FROM bit_tbl;
  a1                    a2                    a3                    a4

=========================================================================
  X'8'                  X'8'                  X'80'                 X'8'
  X'8'                  X'8'                  X'80'                 X'8'
  NULL                  NULL                  X'a0'                 X'a'
  NULL                  NULL                  X'aa'                 X'aa'

BIT VARYING(n)

A variable-length bit string is represented as BIT VARYING (n), where n is the maximum number of bits. If n is not specified, the length is set to 1,073,741,823 (maximum value). n is the maximum number of bits. If n is not specified, the maximum length is set to 1,073,741,823. The bit string is filled with 8-bit values from the left side. For example, the value of B’1’ is the same as the value of B’10000000’. Therefore, it is recommended to declare a length by 8-bit unit, and input a value by 8-bit unit.

Note

If you input B’1’ to the BIT VARYING(4) column, it is printed out X’8’ on CSQL, X’80’ on CUBRID Manager or application program.

  • If the length of the string exceeds n, it is truncated and filled with 0s.
  • The remainder of the string is not filled with 0s even if a bit string smaller than n is stored.
  • n must be a number greater than 0.
  • DEFAULT constraint can be specified in a column of this type.
CREATE TABLE bitvar_tbl(a1 BIT VARYING, a2 BIT VARYING(8));
INSERT INTO bitvar_tbl VALUES (B'1', B'1');
INSERT INTO bitvar_tbl VALUES (0b1010, 0b1010);
INSERT INTO bitvar_tbl VALUES (0xaa, 0xaa);
INSERT INTO bitvar_tbl(a1) VALUES (0xaaa);
SELECT * FROM bitvar_tbl;
  a1                    a2
============================================
  X'8'                  X'8'
  X'a'                  X'a'
  X'aa'                 X'aa'
  X'aaa'                NULL
INSERT INTO bitvar_tbl(a2) VALUES (0xaaa);
ERROR: Data overflow coercing X'aaa' to type bit varying.

Character Strings

CUBRID supports the following two types of character strings:

  • Fixed-length character string: CHAR (n)
  • Variable-length character string: VARCHAR (n)

Note

From CUBRID 9.0 version, NCHAR and NCHAR VARYING is no more supported. Instead, please use CHAR and VARCHAR.

The following are the rules that are applied when using the character string types.

  • In general, single quotations are used to enclose character string. Double quotations may be used as well depending on the value of ansi_quotes, which is a parameter related to SQL statement. If the ansi_quotes value is set to no, character string enclosed by double quotations is handled as character string, not as an identifier. The default value is yes. For details, Statement/Type-Related Parameters.

  • If there are characters that can be considered to be blank (e.g. spaces, tabs, or line breaks) between two character strings, these two character strings are treated as one according to ANSI standard. For example, the following example shows that a line break exists between two character strings.

    'abc'
    'def'
    

    The above two strings and the below string are considered identical.

    'abcdef'
    
  • If you want to include a single quote as part of a character string, enter two single quotes in a row. For example, the character string on the left is stored as the one on the right.

    '''abcde''fghij'       'abcde'fghij
    
  • The maximum size of the token for all the character strings is 16 KB.

  • To enter the language of a specific country, we recommend that you to specify the locale when creating DB, then you can change locale by the introducer CHARSET (or COLLATE modifier). For more information, see An Overview of Globalization.

Length

Specify the number of a character string.

When the length of the character string entered exceeds the length specified, the excess characters are truncated.

For a fixed-length character string type such as CHAR, the length is fixed at the declared length. Therefore, the right part (trailing space) of the character string is filled with space characters when the string is stored. For a variable-length character string type such as VARCHAR, only the entered character string is stored, and the space is not filled with space characters.

The maximum length of a CHAR or VARCHAR type to be specified is 1,073,741,823.

Also, the maximum length that can be input or output in a CSQL statement is 8,192 KB.

Note

In the CUBRID version less than 9.0, the length of CHAR or VARCHAR was not the number of characters, but the byte size.

Character Set, charset

A character set (charset) is a set in which rules are defined that relate to what kind of codes can be used for encoding when specified characters (symbols) are stored in the computer. The character used by CUBRID can be configured as the CUBRID_CHARSET environment variable. For details, see An Overview of Globalization.

Collating Character Sets

A collation is a set of rules used for comparing characters to search or sort values stored in the database when a certain character set is specified. For details, see An Overview of Globalization.

Character String Coercion

Automatic coercion takes place between a fixed-length and a variable-length character string for the comparison of two characters, applicable only to characters that belong to the same character set.

For example, when you extract a column value from a CHAR (5) data type and insert it into a column with a CHAR (10) data type, the data type is automatically coerced to CHAR (10). If you want to coerce a character string explicitly, use the CAST operator (See CAST()).

String compression

Variable character type values (VARCHAR(n)) may be compressed (using LZO1X algorithm) before being stored in database (heap file, index file or list file). Compression is attempted if size in bytes is at least 255 bytes (this value is predefined and cannot be changed). If the compression is not efficient (compressed value size and its overhead is equal or greater than the original uncompressed value), the value is stored uncompressed. Compression is activated by default and may be disabled by setting the system parameter enable_string_compression. The overhead of compression is eight bytes : four for size of compressed buffer and four for the size of expected uncompressed string. Compressed strings are decompressed when they are read from database. To determine if a value is compressed or not, one may use the DISK_SIZE function result and compare it with the result of OCTET_LENGTH function on the same argument. A smaller value for DISK_SIZE (ignoring the value overhead) indicates that compression is used.

CHAR(n)

A fixed-length character string is represented as CHAR (n), in which n represents the number of characters. If n is not specified, the value is specified as 1, default value.

When the length of a character string exceeds n, they are truncated. When character string which is shorter than n is stored, whitespace characters are used to fill up the trailing space.

CHAR (n) and CHARACTER (n) are used interchangeably.

Note

In the earlier versions of CUBRID 9.0, n represents bite length, not the number of characters.

  • n is an integer between 1 and 1,073,741,823 (1G).
  • Empty quotes (‘ ‘) are used to represent a blank string. In this case, the return value of the LENGTH function is not 0, but is the fixed length defined in CHAR (n). That is, if you enter a blank string into a column with CHAR (10), the LENGTH is 10; if you enter a blank value into a CHAR with no length specified, the LENGTH is the default value 1.
  • Space characters used as filling characters are considered to be smaller than any other characters, including special characters.
If you specify 'pacesetter' as CHAR(12), 'pacesetter ' is stored (a 10-character string plus two whitespace characters).
If you specify 'pacesetter ' as CHAR(10), 'pacesetter' is stored (a 10-character string; two whitespace characters are truncated).
If you specify 'pacesetter' as CHAR(4), 'pace' is stored (truncated as the length of the character string is greater than 4).
If you specify 'p ' as CHAR, 'p' is stored (if n is not specified, the length is set to the default value 1).
  • DEFAULT constraint can be specified in a column of this type.

VARCHAR(n)/CHAR VARYING(n)

Variable-length character strings are represented as VARCHAR (n), where n represents the number of characters. If n is not specified, the value is specified as 1,073,741,823, the maximum length.

When the length of a character string exceeds n, they are truncated. When character string which is shorter than n is stored, whitespace characters are used to fill up the trailing space for VARCHAR (n), the length of string used are stored.

VARCHAR (n), CHARACTER, VARYING (n), and CHAR VARYING (n) are used interchangeably.

Note

In the earlier versions of CUBRID 9.0, n represents bite length, not the number of characters.

  • STRING is the same as the VARCHAR (maximum length).
  • n is an integer between 1 and 1,073,741,823 (1G).
  • Empty quotes (‘ ‘) are used to represent a blank string. In this case, the return value of the LENGTH function is not 0.
If you specify 'pacesetter' as CHAR(4), 'pace' is stored (truncated as the length of the character string is greater than 4).
If you specify 'pacesetter' as VARCHAR(12), 'pacesetter' is stored (a 10-character string).
If you specify 'pacesetter ' as VARCHAR(12), 'pacesetter ' is stored (a 10-character string plus two whitespace characters).
If you specify 'pacesetter ' as VARCHAR(10), 'pacesetter' is stored (a 10-character string; two whitespace characters are truncated).
If you specify 'p ' as VARCHAR, 'p' is stored (if n is not specified, the default value 1,073,741,823 is used, and the trailing space is not filled with whitespace characters).
  • DEFAULT constraint can be specified in a column of this type.

STRING

STRING is a variable-length character string data type. STRING is the same as the VARCHAR with the length specified as the maximum value. That is, STRING and VARCHAR (1,073,741,823) have the same value.

Escape Special Characters

CUBRID supports two kinds of methods to escape special characters. One is using quotes and the other is using backslash (\).

  • Escape with Quotes

    If you set no for the system parameter ansi_quotes in the cubrid.conf file, you can use both double quotes (“) and singe quotes (‘) to wrap strings. The default value for the ansi_quotes parameter is yes, and you can use only single quotes to wrap the string.

    • You should use two single quotes (‘’) for the single quotes included in the strings wrapped in single quotes.
    • You should use two double quotes (“”) for the double quotes included in the strings wrapped in double quotes. (when ansi_quotes = no)
    • You don’t need to escape the single quotes included in the string wrapped in double quotes. (when ansi_quotes = no)
    • You don’t need to escape the double quotes included in the string wrapped in single quotes.
  • Escape with Backslash

    You can use escape using backslash (\) only if you set no for the system parameter no_backslash_escapes in the cubrid.conf file. The default value for the no_backslash_escapes parameter is yes. If the value of no_backslash_escapes is no, the following are the special characters.

    • ' : Single quotes (‘)
    • " : Double quotes (“)
    • \n : Newline, linefeed character
    • \r : Carriage return character
    • \t : Tab character
    • \ : Backslash
    • \% : Percent sign (%). For details, see the following description.
    • \_ : Underbar (_). For details, see the following description.

    For all other escapes, the backslash will be ignored. For example, “x” is the same as entering only “x”.

    \% and \_ are used in the pattern matching syntax such as LIKE to search percent signs and underbars and are used as a wildcard character if there is no backslash. Outside of the pattern matching syntax, “\%”and “\_” are recognized as normal strings not wildcard characters. For details, see LIKE.

The following is the result of executing Escape if a value for the system parameter ansi_quotes in the cubrid.conf file is yes(default), and a value for no_backslash_escapes is no.

-- ansi_quotes=yes, no_backslash_escapes=no
SELECT STRCMP('single quotes test('')', 'single quotes test(\')');

If you run the above query, backslash is regarded as an escape character. Therefore, above two strings are the same.

   strcmp('single quotes test('')', 'single quotes test('')')
=============================================================
                                                            0
SELECT STRCMP('\a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z', 'a\bcdefghijklm\nopq\rs\tuvwxyz');

If you run the above query, backslash is regarded as an escape character. Therefore, above two strings are the same.

   strcmp('abcdefghijklm
s       uvwxyz', 'abcdefghijklm
s       uvwxyz')
=====================================================================
                                                                    0
SELECT LENGTH('\\');

If you run the above query, backslash is regarded as an escape character. Therefore, the length of above string is 1.

   char_length('\')
===================
                  1

The following is the result of executing Escape if a value for the system parameter ansi_quotes in the cubrid.conf file is yes(default), and a value for no_backslash_escapes is yes(default). Backslash character is regarded as a general character.

-- ansi_quotes=yes, no_backslash_escapes=yes

SELECT STRCMP('single quotes test('')', 'single quotes test(\')');

If you run the above query, the quotation mark is regarded as opened, so the below error occurs. If you input this query on the CSQL interpreter’s console, it waits the next quotation mark’s input.

ERROR: syntax error, unexpected UNTERMINATED_STRING, expecting SELECT or VALUE or VALUES or '('
SELECT STRCMP('\a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z', 'a\bcdefghijklm\nopq\rs\tuvwxyz');

If you run the above query, backslash is regarded as a general character. Therefore, the result of the comparison between the above two strings shows different.

   strcmp('\a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z', 'a\bcdefghijklm\nopq\rs\tuvwxyz')
===================================================================================================
                                                                                                 -1
SELECT LENGTH('\\');

If you run the above query, backslash is regarded as a general character. Therefore, the length of above string is 2.

   char_length('\\')
====================
                   2

The following shows the result of executing Escape about the LIKE clause when ansi_quotes is yes and no_backslash_escapes is no.

-- ansi_quotes=yes, no_backslash_escapes=no

CREATE TABLE t1 (a VARCHAR(200));
INSERT INTO t1 VALUES ('aaabbb'), ('aaa%');

SELECT a FROM t1 WHERE a LIKE 'aaa\%' ESCAPE '\\';
  a
======================
  'aaa%'

If you run above query, it returns only one row because ‘%’ character is regarded as a general character.

In the string of LIKE clause, backslash is always regarded as a general character. Therefore, if you want to make the ‘%’ character as a general character, not as an pattern matching character, you should specify that ‘%’ is an escape character by using ESCAPE clause. In the ESCAPE clause, backslash is regarded as an escape character. Therefore, we used two backslashes.

If you want use other character than a backslash as an escape character, you can write the query as follows.

SELECT a FROM t1 WHERE a LIKE 'aaa#%' ESCAPE '#';

ENUM Data Type

The ENUM type is a data type consisting of an ordered set of distinct constant char literals called enum values. The syntax for creating an enum column is:

<enum_type>
    : ENUM '(' <char_string_literal_list> ')'

<char_string_literal_list>
    : <char_string_literal_list> ',' CHAR_STRING
    | CHAR_STRING

The following example shows the definition of an ENUM column.

CREATE TABLE tbl (
    color ENUM ('red', 'yellow', 'blue', 'green')
);
  • DEFAULT constraint can be specified in a column of this type.

An index is associated to each element of the enum set, according to the order in which elements are defined in the enum type. For example, the color column can have one of the following values (assuming that the column allows NULL values) :

Value Index Number
NULL NULL
‘red’ 1
‘yellow’ 2
‘blue’ 3
‘green’ 4

The set of values of an ENUM type must not exceed 512 elements and each element of the set must be unique. CUBRID allocates two bytes of storage for each ENUM type value because it only stores the index of each value. This reduces the storage space needed which may improve performance.

Either the enum value or the value index can be used when working with ENUM types. For example, to insert values into an ENUM type column, users can use either the value or the index of the ENUM type:

-- insert enum element 'yellow' with index 2
INSERT INTO tbl (color) VALUES ('yellow');
-- insert enum element 'red' with index 1
INSERT INTO tbl (color) VALUES (1);

When used in expressions, the ENUM type behaves either as a CHAR type or as a number, depending on the context in which it is used:

-- the first result column has ENUM type, the second has INTEGER type and the third has VARCHAR type
SELECT color, color + 0, CONCAT(color, '') FROM tbl;
  color                     color+0   concat(color, '')
=========================================================
  'yellow'                        2  'yellow'
  'red'                           1  'red'

When used in type contexts other than CHAR or numbers, the enum is coerced to that type using either the index or the enum value. The table below shows which part of an ENUM type is used in the coercion:

Type Enum type (Index/Value)
SHORT Index
INTEGER Index
BIGINT Index
FLOAT Index
DOUBLE Index
NUMERIC Index
TIME Value
DATE Value
DATETIME Value
TIMESTAMP Value
CHAR Value
VARCHAR Value
BIT Value
VARBIT Value

ENUM Type Comparisons

When used in = or IN predicates of the form (<enum_column> <operator> <constant>), CUBRID tries to convert the constant to the ENUM type. If the coercion fails, CUBRID does not return an error but considers the comparison to be false. This is implemented like this in order to allow index scan plans to be generated on these two operators.

For all other comparison operators, the ENUM type is converted to the type of the other operand. If a comparison is performed on two ENUM types, both arguments are converted to CHAR type and the comparison follows CHAR type rules. Except for = and IN, predicates on ENUM columns cannot be used in index scan plans.

To understand these rules, consider the following table:

CREATE TABLE tbl (
    color ENUM ('red', 'yellow', 'blue', 'green')
);

INSERT INTO tbl (color) VALUES (1), (2), (3), (4);

The following query will convert the constant ‘red’ to the enum value ‘red’ with index 1

SELECT color FROM tbl WHERE color = 'red';
  color
======================
  'red'
SELECT color FROM tbl WHERE color = 1;
  color
======================
  'red'

The following queries will not return a conversion error but will not return any results:

SELECT color FROM tbl WHERE color = date'2010-01-01';
SELECT color FROM tbl WHERE color = 15;
SELECT color FROM tbl WHERE color = 'asdf';

In the following queries the ENUM type will be converted to the type of the other operand:

-- CHAR comparison using the enum value
SELECT color FROM tbl WHERE color < 'pink';
  color
======================
  'blue'
  'green'
-- INTEGER comparison using the enum index
SELECT color FROM tbl WHERE color > 3;
  color
======================
  'green'
-- Conversion error
SELECT color FROM tbl WHERE color > date'2012-01-01';
ERROR: Cannot coerce value of domain "enum" to domain "date".

ENUM Type Ordering

Values of the ENUM type are ordered by value index, not by enum value. When defining a column with ENUM type, users also define the ordering of the enum values.

SELECT color FROM tbl ORDER BY color ASC;
  color
======================
  'red'
  'yellow'
  'blue'
  'green'

To order the values stored in an ENUM type column as CHAR values, users can cast the enum value to the CHAR type:

SELECT color FROM tbl ORDER BY CAST (color AS VARCHAR) ASC;
  color
======================
  'blue'
  'green'
  'red'
  'yellow'

Notes

The ENUM type is not a reusable type. If several columns require the same set of values, an ENUM type must be defined for each one. When comparing two columns of ENUM type, the comparison is performed as if the columns were coerced to CHAR type even if the two ENUM types define the same set of values.

Using the ALTER … CHANGE statement to modify the set of values of an ENUM type is only allowed if the value of the system parameter alter_table_change_type_strict is set to yes. In this case, CUBRID uses enum value (the char-literal) to convert values to the new domain. If a value is outside of the new ENUM type values set, it is automatically mapped to the empty string(‘’).

CREATE TABLE tbl(color ENUM ('red', 'green', 'blue'));
INSERT INTO tbl VALUES('red'), ('green'), ('blue');

The following statement will extend the ENUM type with the value ‘yellow’:

ALTER TABLE tbl CHANGE color color ENUM ('red', 'green', 'blue', 'yellow');
INSERT into tbl VALUES(4);
SELECT color FROM tbl;
  color
======================
  'red'
  'green'
  'blue'
  'yellow'

The following statement will change all tuples with value ‘green’ to value ‘red’ because the value ‘green’ cannot be converted the new ENUM type:

ALTER TABLE tbl CHANGE color color enum ('red', 'yellow', 'blue');
SELECT color FROM tbl;
  color
======================
  'red'
  ''
  'blue'
  'yellow'

The ENUM type is mapped to char-string types in CUBRID drivers. The following example shows how to use the ENUM type in a JDBC application:

Statement stmt = connection.createStatement("SELECT color FROM tbl");
ResultSet rs = stmt.executeQuery();

while(rs.next()) {
   System.out.println(rs.getString());
}

The following example shows how to use the ENUM type in a CCI application.

req_id = cci_prepare (conn, "SELECT color FROM tbl", 0, &err);
error = cci_execute (req_id, 0, 0, &err);
if (error < CCI_ER_NO_ERROR)
{
    /* handle error */
}

error = cci_cursor (req_id, 1, CCI_CURSOR_CURRENT, &err);
if (error < CCI_ER_NO_ERROR)
{
    /* handle error */
}

error = cci_fetch (req_id, &err);
if (error < CCI_ER_NO_ERROR)
{
    /* handle error */
}

cci_get_data (req, idx, CCI_A_TYPE_STR, &data, 1);

BLOB/CLOB Data Types

An External LOB type is data to process Large Object, such as text or images. When LOB-type data is created and inserted, it will be stored in a file to an external storage, and the location information of the relevant file (LOB Locator) will be stored in the CUBRID database. If the LOB Locator is deleted from the database, the relevant file that was stored in the external storage will be deleted as well. CUBRID supports the following two types of LOB :

  • Binary Large Object (BLOB)
  • Character Large Object (CLOB)

Note

Terminologies

  • LOB (Large Object): Large-sized objects such as binaries or text.
  • FBO (File Based Object): An object that stores data of the database in an external file.
  • External LOB: An object better known as FBO, which stores LOB data in a file into an external DB. It is supported by CUBRID. Internal LOB is an object that stores LOB data inside the DB.
  • External Storage: An external storage to store LOB (example : POSIX file system).
  • LOB Locator: The path name of a file stored in external storage.
  • LOB Data: Details of a file in a specific location of LOB Locator.

When storing LOB data in external storage, the following naming convention will be applied:

{table_name}_{unique_name}
  • table_name : It is inserted as a prefix and able to store the LOB data of many tables in one external storage.
  • unique_name : The random name created by the DB server.

LOB data is stored in the local file system of the DB server. LOB data is stored in the path specified in the -lob-base-path option value of cubrid createdb; if this value is omitted, the data will be stored in the [db-vol path]/lob path where the database volume will be created. For more details, see createdb and To create and manage LOB storage.

If a user change any LOB file without using CUBRID API or CUBRID tools, data consistency is not guaranteed.

If a LOB data file path that was registered to the database directory file(databases.txt) is deleted, please note that database server (cub_server) and standalone utilities will not correctly work.

BLOB

A type that stores binary data outside the database. The maximum length of BLOB data is the maximum file size creatable in an external storage. In SQL statements, the BLOB type expresses the input and output value in a bit string. That is, it is compatible with the BIT (n) and BIT VARYING (n) types, and only an explicit type change is allowed. If data lengths differ from one another, the maximum length is truncated to fit the smaller one. When converting the BLOB type value to a binary value, the length of the converted data cannot exceed 1GB. When converting binary data to the BLOB type, the size of the converted data cannot exceed the maximum file size provided by the BLOB storage.

CLOB

A type that stores character string data outside the database. The maximum length of CLOB data is the maximum file size creatable in an external storage. In SQL statements, the CLOB type expresses the input and output value in a character string. That is, it is compatible with the CHAR (n), VARCHAR (n) types. However, only an explicit type change is allowed, and if data lengths are different from one another, the maximum length is truncated to fit to the smaller one. When converting the CLOB type value to a character string, the length of the converted data cannot exceed 1 GB. When converting a character string to the CLOB type, the size of the converted data cannot exceed the maximum file size provided by the CLOB storage.

To Create and alter LOB

BLOB / CLOB type columns can be created/added/deleted by using a CREATE TABLE statement or an ALTER TABLE statement.

  • You cannot create the index file for a LOB type column.
  • You cannot define the PRIMARY KEY, FOREIGN KEY, UNIQUE, NOT NULL constraints for a LOB type column. However, SHARED property cannot be defined and DEFAULT property can only be defined by the NULL value.
  • LOB type column/data cannot be the element of collection type.
  • If you are deleting a record containing a LOB type column, all files located inside a LOB column value (Locator) and the external storage will be deleted. When a record containing a LOB type column is deleted in a basic key table, and a record of a foreign key table that refers to the foregoing details is deleted at once, all LOB files located in a LOB column value (Locator) and the external storage will be deleted. However, if the relevant table is deleted by using a DROP TABLE statement, or a LOB column is deleted by using an ALTER TABLE…DROP statement, only a LOB column value (LOB Locator) is deleted, and the LOB files inside the external storage which a LOB column refers to will not be deleted.
-- creating a table and CLOB column
CREATE TABLE doc_t (doc_id VARCHAR(64) PRIMARY KEY, content CLOB);

-- an error occurs when UNIQUE constraint is defined on CLOB column
ALTER TABLE doc_t ADD CONSTRAINT content_unique UNIQUE(content);

-- an error occurs when creating an index on CLOB column
CREATE INDEX i_doc_t_content ON doc_t (content);

-- creating a table and BLOB column
CREATE TABLE image_t (image_id VARCHAR(36) PRIMARY KEY, doc_id VARCHAR(64) NOT NULL, image BLOB);

-- an error occurs when adding a BOLB column with NOT NULL constraint
ALTER TABLE image_t ADD COLUMN thumbnail BLOB NOT NULL;

-- an error occurs when adding a BLOB column with DEFAULT attribute
ALTER TABLE image_t ADD COLUMN thumbnail2 BLOB DEFAULT BIT_TO_BLOB(X'010101');

To store and update LOB

In a BLOB / CLOB type column, each BLOB / CLOB type value is stored, and if binary or character string data is input, you must explicitly change the types by using each BIT_TO_BLOB() and CHAR_TO_CLOB() function.

If a value is input in a LOB column by using an INSERT statement, a file is created in an external storage internally and the relevant data is stored; the relevant file path (Locator) is stored in an actual column value.

If a record containing a LOB column uses a DELETE statement, a file to which the relevant LOB column refers will be deleted simultaneously.

If a LOB column value is changed using an UPDATE statement, the column value will be changed following the operation below, according to whether a new value is NULL or not.

  • If a LOB type column value is changed to a value that is not NULL : If a Locator that refers to an external file is already available in a LOB column, the relevant file will be deleted. A new file is created afterwards. After storing a value that is not NULL, a Locator for a new file will be stored in a LOB column value.
  • If changing a LOB type column value to NULL : If a Locator that refers to an external file is already available in a LOB column, the relevant file will be deleted. And then NULL is stored in a LOB column value.
-- inserting data after explicit type conversion into CLOB type column
INSERT INTO doc_t (doc_id, content) VALUES ('doc-1', CHAR_TO_CLOB('This is a Dog'));
INSERT INTO doc_t (doc_id, content) VALUES ('doc-2', CHAR_TO_CLOB('This is a Cat'));

-- inserting data after explicit type conversion into BLOB type column
INSERT INTO image_t VALUES ('image-0', 'doc-0', BIT_TO_BLOB(X'000001'));
INSERT INTO image_t VALUES ('image-1', 'doc-1', BIT_TO_BLOB(X'000010'));
INSERT INTO image_t VALUES ('image-2', 'doc-2', BIT_TO_BLOB(X'000100'));

-- inserting data from a sub-query result
INSERT INTO image_t SELECT 'image-1010', 'doc-1010', image FROM image_t WHERE image_id = 'image-0';

-- updating CLOB column value to NULL
UPDATE doc_t SET content = NULL WHERE doc_id = 'doc-1';

-- updating CLOB column value
UPDATE doc_t SET content = CHAR_TO_CLOB('This is a Dog') WHERE doc_id = 'doc-1';

-- updating BLOB column value
UPDATE image_t SET image = (SELECT image FROM image_t WHERE image_id = 'image-0') WHERE image_id = 'image-1';

-- deleting BLOB column value and its referencing files
DELETE FROM image_t WHERE image_id = 'image-1010';

To access LOB

When you get a LOB type column, the data stored in a file to which the column refers will be displayed. You can execute an explicit type change by using CAST() operator, CLOB_TO_CHAR() and BLOB_TO_BIT() function.

  • If the query is executed in CSQL, a column value (Locator) will be displayed, instead of the data stored in a file. To display the data to which a BLOB / CLOB column refers, it must be changed to strings by CLOB_TO_CHAR() function.
  • To use the string process function, the strings need to be converted by CLOB_TO_CHAR() function.
  • You cannot specify a LOB column in ** GROUP BY** clause and ORDER BY clause.
  • Comparison operators, relational operators, IN, NOT IN operators cannot be used to compare LOB columns. However, IS NULL expression can be used to compare whether it is a LOB column value (Locator) or NULL. This means that TRUE will be returned when a column value is NULL, and if a column value is NULL, there is no file to store LOB data.
  • When a LOB column is created, and the file is deleted after data input, a LOB column value (Locator) will become a state that is referring to an invalid file. As such, using CLOB_TO_CHAR(), BLOB_TO_BIT(), CLOB_LENGTH() and BLOB_LENGTH() functions on the columns that have mismatching LOB Locator and a LOB data file enables them to display NULL.
-- displaying locator value when selecting CLOB and BLOB column in CSQL interpreter
SELECT doc_t.doc_id, content, image FROM doc_t, image_t WHERE doc_t.doc_id = image_t.doc_id;
  doc_id                content               image
==================================================================
  'doc-1'               file:/home1/data1/ces_658/doc_t.00001282208855807171_7329  file:/home1/data1/ces_318/image_t.00001282208855809474_7474
  'doc-2'               file:/home1/data1/ces_180/doc_t.00001282208854194135_5598  file:/home1/data1/ces_519/image_t.00001282208854205773_1215

2 rows selected.
-- using string functions after coercing its type by CLOB_TO_CHAR( )
SELECT CLOB_TO_CHAR(content), SUBSTRING(CLOB_TO_CHAR(content), 10) FROM doc_t;
   clob_to_char(content)  substring( clob_to_char(content) from 10)
============================================
  'This is a Dog'       ' Dog'
  'This is a Cat'       ' Cat'

2 rows selected.
SELECT CLOB_TO_CHAR(content) FROM doc_t WHERE CLOB_TO_CHAR(content) LIKE '%Dog%';
   clob_to_char(content)
======================
  'This is a Dog'
SELECT CLOB_TO_CHAR(content) FROM doc_t ORDER BY CLOB_TO_CHAR(content);
   clob_to_char(content)
======================
  'This is a Cat'
  'This is a Dog'
SELECT * FROM doc_t WHERE content LIKE 'This%';
  doc_id                content
============================================
  'doc-1'               file:/home1/data1/ces_004/doc_t.00001366272829040346_0773
  'doc-2'               file:/home1/data1/ces_256/doc_t.00001366272815153996_1229
-- an error occurs when LOB column specified in ORDER BY/GROUP BY clauses
SELECT * FROM doc_t ORDER BY content;
ERROR: doc_t.content can not be an ORDER BY column

Functions and Operators for LOB

You can explicitly cast bit/string type to BLOB/CLOB type and BLOB/CLOB type to bit/string type with CAST() operator. For more details, see CAST() operator.

CAST (<bit_type_column_or_value> AS { BLOB | CLOB })
CAST (<char_type_column_or_value> AS { BLOB | CLOB })

These are the functions for BLOB/CLOB types. For more details, refer LOB Functions.

Note

” <blob_or_clob_column IS NULL “: using IS NULL condition, it compares the value of LOB column(Locator) if it’s NULL or not. If it’s NULL, this condition returns TRUE.

To create and manage LOB storage

By default, the LOB data file is stored in the <db-volume-path>/lob directory where database volume is created. However, if the lob base path is specified with createdb -B option when creating the database, LOB data files will be stored in the directory designated. However, if the specified directory does not exist, CUBRID tries to create the directory and display an error message when it fails to create it. For more details, see createdb -B option.

# image_db volume is created in the current work directory, and a LOB data file will be stored.
% cubrid createdb image_db en_US

# LOB data file is stored in the "/home1/data1" path within a local file system.
% cubrid createdb --lob-base-path="file:/home1/data1" image_db en_US

You can identify a directory where a LOB file will be stored by executing the cubrid spacedb utility.

% cubrid spacedb image_db

Space description for database 'image_db' with pagesize 16.0K. (log pagesize: 16.0K)

Volid  Purpose  total_size  free_size  Vol Name

    0  GENERIC      512.0M     510.1M  /home1/data1/image_db

Space description for temporary volumes for database 'image_db' with pagesize 16.0K.

Volid  Purpose  total_size  free_size  Vol Name

LOB space description file:/home1/data1

To expand or change the lob-base-path of the database, change its lob-base-path of databases.txt file. Restart the database server to apply the changes made to databases.txt. However, even if you change the lob-base-path of databases.txt, access to the LOB data stored in a previous storage is possible.

# You can change to a new directory from the lob-base-path of databases.txt file.
% cat $CUBRID_DATABASES/databases.txt

#db-name     vol-path           db-host       log-path              lob-base-path
image_db     /home1/data1       localhost     /home1/data1          file:/home1/data2

Backup/recovery for data files of LOB type columns are not supported, while those for meta data(Locator) are supported.

If you are copying a database by using copydb utility, you must configure the databases.txt additionally, as the LOB file directory path will not be copied if the related option is not specified. For more details, see the copydb -B and copydb --copy-lob-path options.

Transaction and Recovery

Commit/Rollback for LOB data changes are supported. That is, it ensures the validation of mapping between LOB Locator and actual LOB data within transactions, and it supports recovery during DB errors. This means that an error will be displayed in case of mapping errors between LOB Locator and LOB data due to the rollback of the relevant transactions, as the database is terminated during transactions. See the example below.

-- csql> ;AUTOCOMMIT OFF

CREATE TABLE doc_t (doc_id VARCHAR(64) PRIMARY KEY, content CLOB);
INSERT INTO doc_t VALUES ('doc-10', CHAR_TO_CLOB('This is content'));
COMMIT;
UPDATE doc_t SET content = CHAR_TO_CLOB('This is content 2') WHERE doc_id = 'doc-10';
ROLLBACK;
SELECT doc_id, CLOB_TO_CHAR(content) FROM doc_t WHERE doc_id = 'doc-10';
  doc_id   content
=========================================================
  'doc-10'  'This is content'
-- csql> ;AUTOCOMMIT OFF

INSERT INTO doc_t VALUES ('doc-11', CHAR_TO_CLOB ('This is content'));
COMMIT;
UPDATE doc_t SET content = CHAR_TO_CLOB('This is content 3') WHERE doc_id = 'doc-11';

-- system crash occurred and then restart server
SELECT doc_id, CLOB_TO_CHAR(content) FROM doc_t WHERE doc_id = 'doc-11';
-- Error : LOB Locator references to the previous LOB data because only LOB Locator is rollbacked.

Note

  • When selecting LOB data in an application through a driver such as JDBC, the driver can get ResultSet from DB server and fetch the record while changing the cursor location on Resultset. That is, only Locator, the meta data of a LOB column, is stored at the time when ResultSet is imported, and LOB data that is referred by a File Locator will be fetched from the file Locator at the time when a record is fetched. Therefore, if LOB data is updated between two different points of time, there could be an error, as the mapping of LOB Locator and actual LOB data will be invalid.
  • Since backup/recovery is supported only for meta data (Locator) of the LOB type columns, an error is likely to occur, as the mapping of LOB Locator and LOB data is invalid if recovery is performed based on a specific point of time.
  • TO execute INSERT the LOB data into other device, LOB data referred by the meta data (Locator) of a LOB column must be read.
  • In a CUBRID HA environment, the meta data (Locator) of a LOB column is replicated and data of a LOB type is not replicated. Therefore, if storage of a LOB type is located on the local machine, no tasks on the columns in a slave node or a master node after failover are allowed.

Warning

Up to CUBRID 2008 R3.0, Large Objects are processed by using glo (Generalized Large Object) classes. However, the glo classes has been deprecated since the CUBRID 2008 R3.1. Instead of it, LOB / CLOB data type is supported. Therefore, both DB schema and application must be modified when upgrading CUBRID in an environment using the previous version of glo classes.

Collection Types

Allowing multiple data values to be stored in a single attribute is an extended feature of relational database. Each element of a collection is possible to have different data type each other except View. Rest types except BLOB and CLOB can be an element of collection types.

Type Description Definition Input Data Stored Data
SET A union which does not allow duplicates col_name SET VARCHAR(20) or col_name SET (VARCHAR(20)) {‘c’,’c’,’c’,’b’,’b’,’a’} {‘a’,’b’,’c’}
MULTISET A union which allows duplicates col_name MULTISET VARCHAR(20) or col_name MULTISET (VARCHAR(20)) {‘c’,’c’,’c’,’b’,’b’,’a’} {‘a’,’b’,’b’,’c’,’c’,’c’}
LIST or SEQUENCE A union which allows duplicates and stores data in the order of input col_name LIST VARCHAR(20) or col_name LIST (VARCHAR(20)) {‘c’,’c’,’c’,’b’,’b’,’a’} {‘c’,’c’,’c’,’b’,’b’,’a’}

As you see the table above, the value specified as a collection type can be inputted with curly braces (‘{‘, ‘}’) each value is separated with a comma (,).

If the specified collection types are identical, the collection types can be cast explicitly by using the CAST operator. The following table shows the collection types that allow explicit coercions.

FROM \ TO SET MULTISET LIST
SET - Yes Yes
MULTISET Yes - No
LIST Yes Yes -

Collection Types do not support collations. Therefore, Below query returns error.

CREATE TABLE tbl (str SET (string) COLLATE utf8_en_ci);
Syntax error: unexpected 'COLLATE', expecting ',' or ')'

SET

SET is a collection type in which each element has different values. Elements of a SET are allowed to have only one data type. It can have records of other tables.

CREATE TABLE set_tbl (col_1 SET (CHAR(1)));
INSERT INTO set_tbl VALUES ({'c','c','c','b','b','a'});
INSERT INTO set_tbl VALUES ({NULL});
INSERT INTO set_tbl VALUES ({''});
SELECT * FROM set_tbl;
  col_1
======================
{'a', 'b', 'c'}
{NULL}
{' '}
SELECT CAST (col_1 AS MULTISET), CAST (col_1 AS LIST) FROM set_tbl;
   cast(col_1 as multiset)   cast(col_1 as sequence)
============================================
  {'a', 'b', 'c'}  {'a', 'b', 'c'}
  {NULL}  {NULL}
  {' '}  {' '}
INSERT INTO set_tbl VALUES ('');
ERROR: Casting '' to type set is not supported.

MULTISET

MULTISET is a collection type in which duplicated elements are allowed. Elements of a MULTISET are allowed to have only one data type. It can have records of other tables.

CREATE TABLE multiset_tbl (col_1 MULTISET (CHAR(1)));
INSERT INTO multiset_tbl VALUES ({'c','c','c','b','b', 'a'});
SELECT * FROM multiset_tbl;
  col_1
======================
  {'a', 'b', 'b', 'c', 'c', 'c'}
SELECT CAST(col_1 AS SET), CAST(col_1 AS LIST) FROM multiset_tbl;
   cast(col_1 as set)   cast(col_1 as sequence)
============================================
  {'a', 'b', 'c'}  {'c', 'c', 'c', 'b', 'b', 'a'}

LIST/SEQUENCE

LIST (= SEQUENCE) is a collection type in which the input order of elements is preserved, and duplications are allowed. Elements of a LIST are allowed to have only one data type. It can have records of other tables.

CREATE TABLE list_tbl (col_1 LIST (CHAR(1)));
INSERT INTO list_tbl VALUES ({'c','c','c','b','b', 'a'});
SELECT * FROM list_tbl;
  col_1
======================
  {'c', 'c', 'c', 'b', 'b', 'a'}
SELECT CAST(col_1 AS SET), CAST(col_1 AS MULTISET) FROM list_tbl;
   cast(col_1 as set)  cast(col_1 as multiset)
============================================
  {'a', 'b', 'c'}  {'a', 'b', 'b', 'c', 'c', 'c'}

JSON Data Type

CUBRID 10.2 adds support for native JSON data type, as defined by RFC 7159. JSON data type offers automatic validation and allows fast access and operations on JSON data.

Note

Old driver versions connecting to CUBRID 10.2 server interpret a JSON type column as Varchar.

Creating JSON data

JSON values are automatically converted (parsed) from string format when they’re assigned to JSON data type columns.

-- assign a string to JSON type column
CREATE TABLE t (id int, j JSON);
INSERT INTO t VALUES (1, '{"a":1}');
SELECT j, TYPEOF(j) FROM t;
  j                     typeof(j)
============================================
  {"a":1}               'json'

Conversions to JSON can also be forced through CAST or by using json keyword before strings.

-- cast string to json
SELECT CAST('{"a":1}' as JSON);
  cast('{"a":1}' as json)
======================
  {"a":1}
-- use json keyword
SELECT json'{"a":1}', TYPEOF (json'{"a":1}');
  json '{"a":1}'         typeof(json '{"a":1}')
============================================
  {"a":1}               'json'

JSON data type may also be created using JSON_OBJECT and JSON_ARRAY functions.

JSON Validation

Conversion to JSON data does built-in validation and reports an error if the string is not a valid JSON.

-- non-quoted string is not a valid json
SELECT json'abc';
In line 1, column 8,

ERROR: before ' ; '
Invalid JSON: 'abc'.

JSON type columns with stricter validation rules can be defined using the draft JSON Schema standard. If you are not familiar with JSON Schema, you may refer to Understanding JSON Schema.

A simple example of how schema can be used:

-- set j column to accept only string type JSON's
CREATE TABLE t (id int, j JSON ('{"type": "string"}'));
-- inserting string type JSON passes schema validation
INSERT into t values (1, '"abc"');
1 command(s) successfully processed.
-- inserting object type JSON does not pass schema validation
INSERT into t values (2, '{"a":1}');
ERROR: before ' ); '
The provided JSON has been invalidated by the JSON schema (Invalid schema path: #, Keyword: type, Invalid provided JSON path: #)

JSON Value Types

A JSON value must be an object, an array or a scalar (string, number, boolean or null), as defined by RFC 7159.

A table of JSON value types:

Type CUBRID JSON type Description
Object JSON_OBJECT A set of key-value pairs
Array JSON_ARRAY An array of JSON values
Scalar String STRING A quoted string
Number INTEGER 32-bit signed integer
BIGINT 64-bit signed integer
DOUBLE Non-integer number or integer bigger than 263- 1
true BOOLEAN True boolean value
false BOOLEAN False boolean value
null JSON_NULL Null value

The CUBRID JSON type of a JSON value can be obtained with JSON_TYPE function.

JSON Data Conversions

JSON data types can be obtained by explicit or implicit casting from and to other types.

Casting a JSON value to JSON type may fail if desired type has a schema and converted value does not pass schema validation.

Converting other types to JSON is explained by next table:

Original type CUBRID JSON type
Any string

String is parsed as JSON data. The result may be of any type.

Note

If string codeset is not UTF8, string is first converted to UTF8 and then parsed.

Short, Integer INTEGER
Bigint BIGINT
Float, Double DOUBLE
Numeric DOUBLE

Converting JSON data type to other types is explained by next table:

CUBRID JSON Type Other accepted types
JSON_OBJECT String with printed JSON
JSON_ARRAY String with printed JSON
STRING Any type that a string can be converted to
INTEGER Any type that an integer can be converted to
BIGINT Any type that a bigint can be converted to
DOUBLE Any type that a double can be converted to
BOOLEAN “true” or “false” if converted to string
0 or 1 if converted to a numeric type
JSON_NULL String with printed JSON ‘null’

JSON Paths

JSON Paths provide ways of addressing json elements inside a JSON. Many of the JSON functions require a JSON Path or JSON Pointer argument to define the location inside the JSON where operations are performed. JSON Paths always start with ‘$’ and may be followed by array indexes, object key tokens and wildcards. If ‘$’ is followed by no other tokens, then path points to JSON data root.

<json_path>::=
   <start_token> [<path_token>] ...

<start_token>::=
   $

<path_token>::=
   <array_access_token> | <object_key_access_token> | <wildcard_token>

<array_access_token>::=
   [idx]

<object_key_access_token>::=
   .[key_identifier | "key_str"]

<wildcard_token>::=
   .*|[*]|**path_token

As an example, relative to ‘{“a”:[0,1,2,{“b”:5}]}’ ‘$.a[3].b’ would mean: “The member having key ‘b’ of the element at index 3 of the member having key ‘a’ of the root” and would address the json value ‘5’; Object_key_access_tokens as key string can be used to express the same key_identifiers and can also enable using characters that need escaping, e.g. ‘$.”””’ can be used to refer to a member having a double quote as a key.

JSON wildcards can be one of three types:

  • .* , object member access matching wildcards
  • [*], array index access matching wildcards
  • **, matching a sequence of object keys and array indexes. ** wildcards must be suffixed by a token

Path expressions, like JSON Pointers and JSON text, should be encoded using ASCII or UTF-8 character set. If other character sets are used, a coercion will be done to UTF-8.

JSON Pointers

JSON Pointers, as defined by https://tools.ietf.org/html/rfc6901 provide an alternative to JSON paths. JSON Pointers, like JSON Paths and JSON text, should be encoded using ASCII or UTF-8 character set. If other character sets are used, a coercion will be done to UTF-8.

<json_pointer>::=
   [/path_token] ... [/-]
'$.a[10].bb' is equivalent to '/a/10/bb'
'$' is equivalent to ''

The special character ‘-‘ can be used exclusively as a last path_token and can be used to address the end of a json_array.

JSON pointers can be used to address the same path as their corresponding no-wildcards JSON paths.

Implicit Type Conversion

An implicit type conversion represents an automatic conversion of a type of expression to a corresponding type.

SET, MULTISET, LIST and SEQUENCE should be converted explicitly.

If you convert the DATETIME and the TIMESTAMP types (including types having timezone) to the DATE type or the TIME type, data loss may occur. If you convert the DATE type to the DATETIME type or the TIMESTAMP type (or types with timezone), the time will be set to ‘12:00:00 AM.’

Timezone part of values with timezone types has only a reference purpose, their absolute value is stored as UTC reference. When converting from a value of type with timezone to a type without timezone, a conversion is operated as if session timezone is used. When converting from a value of type without timezone to a type with timezone, the conversion takes place considering the session timezone. For more details on converting to/from value with timezone type see Date/Time Types.

If you convert a string type or an exact numeric type to a floating-point numeric type, the value may not be accurate. Because a string type and an exact type use a decimal precision to represent the value, but a floating-point numeric type uses a binary precision.

The implicit type conversion executed by CUBRID is as follows:

Implicit Type Conversion Table 1

From \ To DATETIME DATETIMELTZ DATETIMETZ DATE TIME TIMESTAMP TIMESTAMPLTZ TIMESTAMPTZ
DATETIME - O O O O O O O
DATETIMELTZ O - O O O O O O
DATETIMETZ O O - O O O O O
DATE O O O -   O O O
TIME         -      
TIMESTAMP O O O O O - O O
TIMESTAMPLTZ O O O O O O - O
TIMESTAMPTZ O O O O O O O -
DOUBLE         O O O O
FLOAT         O O O O
NUMERIC           O O O
BIGINT         O O O O
INT         O O O O
SHORT         O O O O
BIT                
VARBIT                
CHAR O O O O O O O O
VARCHAR O O O O O O O O

Limitations when numeric value is changed as TIME or TIMESTAMP (TIMESTAMPLTZ, TIMESTAMPTZ)

  • All numeric types except for NUMERIC type can be converted into TIME type; at this time, it represents a value of the remainder which is calculated by dividing the input number into 86,400 seconds(1 day), and the remainder is calculated as seconds.
  • All numeric types including NUMERIC can be converted into TIMESTAMP, TIMESTAMPLTZ, TIMESTAMPTZ types ; at this time, the input number cannot exceed 2,147,483,647 as the maximum.

Implicit Type Conversion Table 2

From \ To INT SHORT BIT VARBIT CHAR VARCHAR DOUBLE FLOAT NUMERIC BIGINT
DATETIME         O O        
DATETIMELTZ         O O        
DATETIMETZ         O O        
DATE         O O        
TIME         O O        
TIMESTAMP         O O        
TIMESTAMPLTZ         O O        
TIMESTAMPTZ         O O        
DOUBLE O O     O O - O O O
FLOAT O O     O O O - O O
NUMERIC O O     O O O O - O
BIGINT O O     O O O O O -
INT - O     O O O O O O
SHORT O -     O O O O O O
BIT     - O O O        
VARBIT     O - O O        
CHAR O O O O - O O O O O
VARCHAR O O O O O - O O O O

Conversion Rules

INSERT and UPDATE

The type will be converted to the type of the column affected.

CREATE TABLE t(i INT);
INSERT INTO t VALUES('123');

SELECT * FROM t;
            i
=============
          123

Function

If the parameter value entered in the function can be converted to the specified type, the parameter type will be converted. The strings are converted to numbers because the input parameter expected in the following function is a number.

SELECT MOD('123','2');
           mod('123', '2')
==========================
     1.000000000000000e+00

You can enter multiple type values in the function. If the type value not specified in the function is delivered, the type will be converted depending on the following priority order.

  • Date/Time Type ( DATETIME > TIMESTAMP > DATE > TIME )
  • Approximate Numeric Type ( DOUBLE > FLOAT )
  • Exact Numeric Type ( NUMERIC > BIGINT > INT > SHORT )
  • String Type ( CHAR > VARCHAR )

Comparison Operation

The following are the conversion rules according to an operand type of the comparison operator.

operand1 Type operand2 Type Conversion Comparison
Numeric Type Numeric Type None NUMERIC
String Type Converts operand2 to DOUBLE NUMERIC
Date/Time Type Converts operand1 to Date/Time TIME/TIMESTAMP
String Type Numeric Type Converts operand1 to DOUBLE NUMERIC
String Type None String
Date/Time Type Converts operand1 to Date/Time type Date/Time
Date/Time Type Numeric Type Converts operand2 to Date/Time TIME/TIMESTAMP
String Type Converts operand2 to Date/Time type Date/Time
Date/Time Type Converts it to the type with higher priority Date/Time

When Date/Time type and numeric type are compared, see Limitations when numeric value is changed as TIME or TIMESTAMP of the above table.

There are exceptions when operand1 is string type and operand2 is a value.

operand1 Type operand2 Type Conversion Comparison
String type Numeric type Converts operand2 to the string type String
Date/Time type Converts operand2 to the string type String

If operand2 is a set operator( IS IN, IS NOT IN, = ALL, = ANY, < ALL, < ANY, <= ALL, <= ANY, >= ALL, >= ANY ), the exception above is not applied.

The following is examples of implicit type conversion in comparison operations.

  • Numeric Type & String Type Operands

    The string type operand will be converted to DOUBLE.

    CREATE TABLE t1(i INT, s STRING);
    INSERT INTO t1 VALUES(1,'1'),(2,'2'),(3,'3'),(4,'4'), (12,'12');
    
    SELECT i FROM t1 WHERE i < '11.3';
    
                i
    =============
                1
                2
                3
                4
    
    SELECT ('2' <= 11);
    
         ('2'<11)
    =============
                1
    
  • String Type & Date/Time Type Operands

    The string type operand will be converted to the date/time type.

    SELECT ('2010-01-01' < date'2010-02-02');
    
       ('2010-01-01'<date '2010-02-02')
    ==================================
                                    1
    
    SELECT (date'2010-02-02' >= '2010-01-01');
    
      (date '2010-02-02'>='2010-01-01')
    ===================================
                                    1
    
  • String Type & Numeric Type Host Variable Operands

    The numeric type host variable will be converted to the string type.

    PREPARE s FROM 'SELECT s FROM t1 WHERE s < ?';
    EXECUTE s USING 11;
    
           s
    ===================
         '1'
    
  • String Type & Numeric Type value Operands

    The numeric type value will be converted to the string type.

    SELECT s FROM t1 WHERE s > 11;
    
           s
    ==================
         '2'
         '3'
         '4'
         '12'
    
    SELECT s FROM t1 WHERE s BETWEEN 11 AND 33;
    
            s
    ======================
          '2'
          '3'
          '12'
    
  • String Type Column & Date/Time Type Value Operands

    The date/time type value will be converted to the string type.

    CREATE TABLE t2 (s STRING);
    INSERT INTO t2 VALUES ('01/01/1998'), ('01/01/1999'), ('01/01/2000');
    SELECT s FROM t2;
    
               s
    ======================
        '01/01/1998'
        '01/01/1999'
        '01/01/2000'
    
    SELECT s FROM t2 WHERE s <= date'02/02/1998';
    

    In the above query, comparison operation is performed by converting date’02/02/1998’ into string ‘02/02/1998’.

                s
    ======================
        '01/01/1998'
        '01/01/1999'
        '01/01/2000'
    

Range Operation

  • Numeric Type and String Type Operands

    The string type operand will be converted to DOUBLE.

    CREATE TABLE t3 (i INT);
    INSERT INTO t3 VALUES (1), (2), (3), (4);
    SELECT i FROM t3 WHERE i <= ALL {'11','12'};
    
                i
    =============
                1
                2
                3
                4
    
  • String Type and Date/Time Type Operands

    The string type operand will be converted to the date/time type.

    SELECT s FROM t2;
    
      s
    =================
      '01/01/1998'
      '01/01/1999'
      '01/01/2000'
    
    SELECT s FROM t2 WHERE s <= ALL {date'02/02/1998',date'01/01/2000'};
    
      s
    ================
     '01/01/1998'
    

    An error will be returned if it cannot be converted to the corresponding type.

Arithmetic Operation

  • Date/Time Type Operand

    If the date/time type operands are given to ‘-‘ operator and the types are different from each other, it will be converted to the type with a higher priority. The following example shows that the operand data type on the left is converted from DATE to DATETIME so that the result of ‘-‘ operation of DATETIME can be outputted in milliseconds.

    SELECT date'2002-01-01' - datetime'2001-02-02 12:00:00 am';
    
       date '2002-01-01'- datetime '2001-02-02 12:00:00 am'
    =====================================================
                                              28771200000
    
  • Numeric Type Operand

    If the numeric type operands are given and the types are different from each other, it will be converted to the type with the higher priority.

  • Date/Time Type & Numeric Type Operands

    If the date/time type and the numeric type operands are given to ‘+’ or ‘-‘ operator, the numeric type operand is converted to either BIGINT, INT or SHORT.

  • Date/Time Type & String Type Operands

    If a date/time type and a string type are operands, only ‘+’ and ‘-‘ operators are allowed. If the ‘+’ operator is used, it will be applied according to the following rules.

    • The string type will be converted to BIGINT with an interval value. The interval is the smallest unit for operands in the Date/Time type, and the interval for each type is as follows:
      • DATE : Days
      • TIME, TIMESTAMP : Seconds
      • DATETIME : Milliseconds
    • Floating-point numbers are rounded.
    • The result type is the type of an date/time operand.
    SELECT date'2002-01-01' + '10';
    
      date '2002-01-01'+'10'
    ======================
      01/11/2002
    

    If the date/time type and a string type are operands and the ‘-‘ operator is used, they will be applied according to the following rules.

    • If the date/time type operands are DATE, DATETIME and TIMESTAMP, the string will be converted to DATETIME; if the date/time operand is TIME, the string is converted to TIME.
    • The result type is always BIGINT.
    SELECT date'2002-01-01'-'2001-01-01';
    
      date '2002-01-01'-'2001-01-01'
    ================================
                        31536000000
    
    -- this causes an error
    
    SELECT date'2002-01-01'-'10';
    
    ERROR: Cannot coerce '10' to type datetime.
    
  • Numeric Type & String Type Operands

    If a numeric type and a string type are operands, they will be applied according to the following rules.

    • Strings will be converted to DOUBLE when possible.
    • The result type is DOUBLE and depends on the type of the numeric operand.
    SELECT 4 + '5.2';
    
                    4+'5.2'
    ==========================
      9.199999999999999e+00
    

    Unlike CUBRID 2008 R3.1 and the earlier versions, the string in the date/time format, that is, the string such as ‘2010-09-15’ is not converted to the date/time type. You can use a literal DATE’2010-09-15’ with the date/time type for addition and subtraction operations.

    SELECT '2002-01-01'+1;
    
    ERROR: Cannot coerce '2002-01-01' to type double.
    
    SELECT DATE'2002-01-01'+1;
    
      date '2002-01-01'+1
    =====================
      01/02/2002
    
  • String Type Operand

    If you multiply, divide or subtract both strings, the result returns a DOUBLE type value.

    SELECT '3'*'2';
    
                         '3'*'2'
    ============================
           6.000000000000000e+00
    

    The ‘+’ operator action depends on how to set the system parameter plus_as_concat in the cubrid.conf file. For details, see Statement/Type-Related Parameters.

    • If a value for plus_as_concat is yes (default value), the concatenation of two strings will be returned.

      SELECT '1'+'1';
      
                     '1'+'1'
      ======================
                        '11'
      
    • If a value for plus_as_concat is no and two strings can be converted to numbers, the DOUBLE type value will be returned by adding the two numbers.

      SELECT '1'+'1';
      
                         '1'+'1'
      ==========================
           2.000000000000000e+00
      

    An error will be returned if it cannot be converted to the corresponding type.