Functions
Index
Numeric Functions
String Functions
Time and Date Functions
System Functions
JSON Functions
|
JSON_OBJECT |
JSON_ARRAY |
Table Functions
|
CSVREAD LINK_SCHEMA |
TABLE UNNEST |
Details
Click on the header of the function to switch between railroad diagram and BNF.
Non-standard syntax is marked in green. Compatibility-only non-standard syntax is marked in red, don't use it unless you need it for compatibility with other databases or old versions of H2.
Numeric Functions
ABS
Returns the absolute value of a specified value. The returned value is of the same data type as the parameter.
Note that TINYINT, SMALLINT, INT, and BIGINT data types cannot represent absolute values of their minimum negative values, because they have more negative values than positive. For example, for INT data type allowed values are from -2147483648 to 2147483647. ABS(-2147483648) should be 2147483648, but this value is not allowed for this data type. It leads to an exception. To avoid it cast argument of this function to a higher data type.
Example:
ABS(I)
ABS(CAST(I AS BIGINT))
ACOS
ACOS ( numeric ) |
Calculate the arc cosine.
Argument must be between -1 and 1 inclusive.
This function returns a double precision value.
Example:
ACOS(D)
ASIN
ASIN ( numeric ) |
Calculate the arc sine.
Argument must be between -1 and 1 inclusive.
This function returns a double precision value.
Example:
ASIN(D)
ATAN
ATAN ( numeric ) |
Calculate the arc tangent.
This function returns a double precision value.
Example:
ATAN(D)
COS
COS ( numeric ) |
Calculate the trigonometric cosine.
This function returns a double precision value.
Example:
COS(ANGLE)
COSH
COSH ( numeric ) |
Calculate the hyperbolic cosine.
This function returns a double precision value.
Example:
COSH(X)
COT
COT ( numeric ) |
Calculate the trigonometric cotangent (1/TAN(ANGLE)).
This function returns a double precision value.
Example:
COT(ANGLE)
SIN
SIN ( numeric ) |
Calculate the trigonometric sine.
This function returns a double precision value.
Example:
SIN(ANGLE)
SINH
SINH ( numeric ) |
Calculate the hyperbolic sine.
This function returns a double precision value.
Example:
SINH(ANGLE)
TAN
TAN ( numeric ) |
Calculate the trigonometric tangent.
This function returns a double precision value.
Example:
TAN(ANGLE)
TANH
TANH ( numeric ) |
Calculate the hyperbolic tangent.
This function returns a double precision value.
Example:
TANH(X)
ATAN2
Calculate the angle when converting the rectangular coordinates to polar coordinates.
This function returns a double precision value.
Example:
ATAN2(X, Y)
BITAND
BITAND ( expression , expression ) |
The bitwise AND operation. Arguments should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
For aggregate function see BIT_AND_AGG.
Example:
BITAND(A, B)
BITOR
BITOR ( expression , expression ) |
The bitwise OR operation. Arguments should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
For aggregate function see BIT_OR_AGG.
Example:
BITOR(A, B)
BITXOR
BITXOR ( expression , expression ) |
Arguments should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
For aggregate function see BIT_XOR_AGG.
Example:
The bitwise XOR operation.
BITNOT
BITNOT ( expression ) |
The bitwise NOT operation. Argument should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
Example:
BITNOT(A)
BITNAND
BITNAND ( expression , expression ) |
The bitwise NAND operation equivalent to BITNOT(BITAND(expression, expression)). Arguments should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
For aggregate function see BIT_NAND_AGG.
Example:
BITNAND(A, B)
BITNOR
BITNOR ( expression , expression ) |
The bitwise NOR operation equivalent to BITNOT(BITOR(expression, expression)). Arguments should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
For aggregate function see BIT_NOR_AGG.
Example:
BITNOR(A, B)
BITXNOR
BITXNOR ( expression , expression ) |
The bitwise XNOR operation equivalent to BITNOT(BITXOR(expression, expression)). Arguments should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
For aggregate function see BIT_XNOR_AGG.
Example:
BITXNOR(A, B)
BITGET
BITGET ( expression , long ) |
Returns true if and only if the first argument has a bit set in the position specified by the second parameter. The first argument should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This method returns a boolean. The second argument is zero-indexed; the least significant bit has position 0.
Example:
BITGET(A, 1)
BITCOUNT
BITCOUNT ( expression ) |
Returns count of set bits in the specified value. Value should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This method returns a long.
Example:
BITCOUNT(A)
LSHIFT
LSHIFT ( expression , long ) |
The bitwise signed left shift operation. Shifts the first argument by the number of bits given by the second argument. Argument should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
If number of bits is negative, a signed right shift is performed instead. For numeric values a sign bit is used for left-padding (with negative offset). If number of bits is equal to or larger than number of bits in value all bits are pushed out from the value. For binary string arguments signed and unsigned shifts return the same results.
Example:
LSHIFT(A, B)
RSHIFT
RSHIFT ( expression , long ) |
The bitwise signed right shift operation. Shifts the first argument by the number of bits given by the second argument. Argument should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
If number of bits is negative, a signed left shift is performed instead. For numeric values a sign bit is used for left-padding (with positive offset). If number of bits is equal to or larger than number of bits in value all bits are pushed out from the value. For binary string arguments signed and unsigned shifts return the same results.
Example:
RSHIFT(A, B)
ULSHIFT
ULSHIFT ( expression , long ) |
The bitwise unsigned left shift operation. Shifts the first argument by the number of bits given by the second argument. Argument should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
If number of bits is negative, an unsigned right shift is performed instead. If number of bits is equal to or larger than number of bits in value all bits are pushed out from the value. For binary string arguments signed and unsigned shifts return the same results.
Example:
ULSHIFT(A, B)
URSHIFT
URSHIFT ( expression , long ) |
The bitwise unsigned right shift operation. Shifts the first argument by the number of bits given by the second argument. Argument should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
If number of bits is negative, an unsigned left shift is performed instead. If number of bits is equal to or larger than number of bits in value all bits are pushed out from the value. For binary string arguments signed and unsigned shifts return the same results.
Example:
URSHIFT(A, B)
ROTATELEFT
ROTATELEFT ( expression , long ) |
The bitwise left rotation operation. Rotates the first argument by the number of bits given by the second argument. Argument should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
Example:
ROTATELEFT(A, B)
ROTATERIGHT
ROTATERIGHT ( expression , long ) |
The bitwise right rotation operation. Rotates the first argument by the number of bits given by the second argument. Argument should have TINYINT, SMALLINT, INTEGER, BIGINT, BINARY, or BINARY VARYING data type. This function returns result of the same data type.
Example:
ROTATERIGHT(A, B)
MOD
MOD ( dividendNumeric , divisorNumeric ) |
The modulus expression.
Result has the same type as divisor. Result is NULL if either of arguments is NULL. If divisor is 0, an exception is raised. Result has the same sign as dividend or is equal to 0.
Usually arguments should have scale 0, but it isn't required by H2.
Example:
MOD(A, B)
CEIL
| ( numeric ) |
Returns the smallest integer value that is greater than or equal to the argument. This method returns value of the same type as argument, but with scale set to 0 and adjusted precision, if applicable.
Example:
CEIL(A)
DEGREES
DEGREES ( numeric ) |
See also Java Math.toDegrees. This method returns a double.
Example:
DEGREES(A)
EXP
EXP ( numeric ) |
See also Java Math.exp. This method returns a double.
Example:
EXP(A)
FLOOR
FLOOR ( numeric ) |
Returns the largest integer value that is less than or equal to the argument. This method returns value of the same type as argument, but with scale set to 0 and adjusted precision, if applicable.
Example:
FLOOR(A)
LN
LN ( numeric ) |
Calculates the natural (base e) logarithm as a double value. Argument must be a positive numeric value.
Example:
LN(A)
LOG
LOG ( |
| ) |
Calculates the logarithm with specified base as a double value. Argument and base must be positive numeric values. Base cannot be equal to 1.
The default base is e (natural logarithm), in the PostgreSQL mode the default base is base 10. In MSSQLServer mode the optional base is specified after the argument.
Single-argument variant of LOG function is deprecated, use LN or LOG10 instead.
Example:
LOG(2, A)
LOG10
LOG10 ( numeric ) |
Calculates the base 10 logarithm as a double value. Argument must be a positive numeric value.
Example:
LOG10(A)
ORA_HASH
ORA_HASH ( expression |
| ) |
Computes a hash value. Optional bucket argument determines the maximum returned value. This argument should be between 0 and 4294967295, default is 4294967295. Optional seed argument is combined with the given expression to return the different values for the same expression. This argument should be between 0 and 4294967295, default is 0. This method returns a long value between 0 and the specified or default bucket value inclusive.
Example:
ORA_HASH(A)
RADIANS
RADIANS ( numeric ) |
See also Java Math.toRadians. This method returns a double.
Example:
RADIANS(A)
SQRT
SQRT ( numeric ) |
See also Java Math.sqrt. This method returns a double.
Example:
SQRT(A)
PI
PI ( ) |
See also Java Math.PI. This method returns a double.
Example:
PI()
POWER
See also Java Math.pow. This method returns a double.
Example:
POWER(A, B)
RAND
| ( |
| ) |
Calling the function without parameter returns the next a pseudo random number. Calling it with an parameter seeds the session's random number generator. This method returns a double between 0 (including) and 1 (excluding).
Example:
RAND()
RANDOM_UUID
| |||||||||||
|
Returns a new RFC 9562-compliant UUID with the specified version. If version is not specified, a default version will be used. Current default is 4, but it may be changed in future versions of H2.
Version 4 is a UUID with 122 pseudo random bits. Please note that using an index on randomly generated data will result on poor performance once there are millions of rows in a table. The reason is that the cache behavior is very bad with randomly distributed data. This is a problem for any database system.
Version 7 is a time-ordered UUID value with layout optimized for database systems. It contains 48-bit number of milliseconds seconds since midnight 1 Jan 1970 UTC with leap seconds excluded, additional 12-bit sub-millisecond timestamp fraction if available, and 62 pseudo random bits.
Example:
RANDOM_UUID(7)
RANDOM_UUID()
ROUND
Rounds to a number of fractional digits. This method returns value of the same type as argument, but with adjusted precision and scale, if applicable.
Example:
ROUND(N, 2)
SECURE_RAND
SECURE_RAND ( int ) |
Generates a number of cryptographically secure random numbers. This method returns bytes.
Example:
CALL SECURE_RAND(16)
SIGN
Returns -1 if the value is smaller than 0, 0 if zero or NaN, and otherwise 1.
Example:
SIGN(N)
ENCRYPT
ENCRYPT ( algorithmString , keyBytes , dataBytes ) |
Encrypts data using a key. The supported algorithm is AES. The block size is 16 bytes. This method returns bytes.
Example:
CALL ENCRYPT('AES', '00', STRINGTOUTF8('Test'))
DECRYPT
DECRYPT ( algorithmString , keyBytes , dataBytes ) |
Decrypts data using a key. The supported algorithm is AES. The block size is 16 bytes. This method returns bytes.
Example:
CALL TRIM(CHAR(0) FROM UTF8TOSTRING(
DECRYPT('AES', '00', '3fabb4de8f1ee2e97d7793bab2db1116')))
HASH
HASH ( algorithmString , expression |
| ) |
Calculate the hash value using an algorithm, and repeat this process for a number of iterations.
This function supports MD5, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, SHA3-224, SHA3-256, SHA3-384, and SHA3-512 algorithms. SHA-224, SHA-384, and SHA-512 may be unavailable in some JREs.
MD5 and SHA-1 algorithms should not be considered as secure.
If this function is used to encrypt a password, a random salt should be concatenated with a password and this salt and result of the function should be stored to prevent a rainbow table attack and number of iterations should be large enough to slow down a dictionary or a brute force attack.
This method returns bytes.
Example:
CALL HASH('SHA-256', 'Text', 1000)
CALL HASH('SHA3-256', X'0102')
TRUNC
When a numeric argument is specified, truncates it to a number of digits (to the next value closer to 0) and returns value of the same type as argument, but with adjusted precision and scale, if applicable.
This function with datetime or string argument is deprecated, use DATE_TRUNC instead. When used with a timestamp, truncates the timestamp to a date (day) value and returns a timestamp with or without time zone depending on type of the argument. When used with a date, returns a timestamp at start of this date. When used with a timestamp as string, truncates the timestamp to a date (day) value and returns a timestamp without time zone.
Example:
TRUNCATE(N, 2)
COMPRESS
COMPRESS ( dataBytes |
| ) |
Compresses the data using the specified compression algorithm. Supported algorithms are: LZF (faster but lower compression; default), and DEFLATE (higher compression). Compression does not always reduce size. Very small objects and objects with little redundancy may get larger. This method returns bytes.
Example:
COMPRESS(STRINGTOUTF8('Test'))
EXPAND
EXPAND ( bytes ) |
Expands data that was compressed using the COMPRESS function. This method returns bytes.
Example:
UTF8TOSTRING(EXPAND(COMPRESS(STRINGTOUTF8('Test'))))
ZERO
ZERO ( ) |
Returns the value 0. This function can be used even if numeric literals are disabled.
Example:
ZERO()
String Functions
ASCII
ASCII ( string ) |
Returns the ASCII value of the first character in the string. This method returns an int.
Example:
ASCII('Hi')
BIT_LENGTH
BIT_LENGTH ( bytes ) |
Returns the number of bits in a binary string. This method returns a long.
Example:
BIT_LENGTH(NAME)
CHAR_LENGTH
| ( string ) |
Returns the number of characters in a character string. This method returns a long.
Example:
CHAR_LENGTH(NAME)
OCTET_LENGTH
OCTET_LENGTH ( bytes ) |
Returns the number of bytes in a binary string. This method returns a long.
Example:
OCTET_LENGTH(NAME)
CHAR
| ( int ) |
Returns the character that represents the ASCII value. This method returns a string.
Example:
CHAR(65)
CONCAT
Combines strings. Unlike with the operator ||, NULL parameters are ignored, and do not cause the result to become NULL. If all parameters are NULL the result is an empty string. This method returns a string.
Example:
CONCAT(NAME, '!')
CONCAT_WS
CONCAT_WS ( separatorString , string , string |
| ) |
Combines strings with separator. If separator is NULL it is treated like an empty string. Other NULL parameters are ignored. Remaining non-NULL parameters, if any, are concatenated with the specified separator. If there are no remaining parameters the result is an empty string. This method returns a string.
Example:
CONCAT_WS(',', NAME, '!')
DIFFERENCE
Returns the difference between the sounds of two strings. The difference is calculated as a number of matched characters in the same positions in SOUNDEX representations of arguments. This method returns an int between 0 and 4 inclusive, or null if any of its parameters is null. Note that value of 0 means that strings are not similar to each other. Value of 4 means that strings are fully similar to each other (have the same SOUNDEX representation).
Example:
DIFFERENCE(T1.NAME, T2.NAME)
HEXTORAW
HEXTORAW ( string ) |
Converts a hex representation of a string to a string. 4 hex characters per string character are used.
Example:
HEXTORAW(DATA)
RAWTOHEX
Converts a string or bytes to the hex representation. 4 hex characters per string character are used. This method returns a string.
Example:
RAWTOHEX(DATA)
INSERT Function
INSERT ( originalString , startInt , lengthInt , addString ) |
Inserts a additional string into the original string at a specified start position. The length specifies the number of characters that are removed at the start position in the original string. This method returns a string.
Example:
INSERT(NAME, 1, 1, ' ')
LOWER
| ( string ) |
Converts a string to lowercase.
Example:
LOWER(NAME)
UPPER
| ( string ) |
Converts a string to uppercase.
Example:
UPPER(NAME)
LEFT
Returns the leftmost number of characters.
Example:
LEFT(NAME, 3)
RIGHT
Returns the rightmost number of characters.
Example:
RIGHT(NAME, 3)
LOCATE
| ||||||||||||
| ||||||||||||
|
Returns the location of a search string in a string. If a start position is used, the characters before it are ignored. If position is negative, the rightmost location is returned. 0 is returned if the search string is not found. Please note this function is case sensitive, even if the parameters are not.
Example:
LOCATE('.', NAME)
LPAD
LPAD ( string , int |
| ) |
Left pad the string to the specified length. If the length is shorter than the string, it will be truncated at the end. If the padding string is not set, spaces will be used.
Example:
LPAD(AMOUNT, 10, '*')
RPAD
RPAD ( string , int |
| ) |
Right pad the string to the specified length. If the length is shorter than the string, it will be truncated. If the padding string is not set, spaces will be used.
Example:
RPAD(TEXT, 10, '-')
LTRIM
LTRIM ( string |
| ) |
Removes all leading spaces or other specified characters from a string, multiple characters can be specified.
Example:
LTRIM(NAME)
LTRIM(NAME, ' _~');
RTRIM
RTRIM ( string |
| ) |
Removes all trailing spaces or other specified characters from a string, multiple characters can be specified.
Example:
RTRIM(NAME)
RTRIM(NAME, ' _~');
BTRIM
BTRIM ( string |
| ) |
Removes all leading and trailing spaces or other specified characters from a string, multiple characters can be specified.
Example:
BTRIM(NAME)
BTRIM(NAME, ' _~');
TRIM
TRIM ( |
| string ) |
Removes all leading spaces, trailing spaces, or spaces at both ends from a string. If character to trim is specified, these characters are removed instead of spaces, only one character can be specified. To trim multiple different characters use LTRIM, RTRIM, or BTRIM.
If neither LEADING, TRAILING, nor BOTH are specified, BOTH is implicit.
Example:
TRIM(NAME)
TRIM(LEADING FROM NAME)
TRIM(BOTH '_' FROM NAME)
REGEXP_REPLACE
REGEXP_REPLACE ( inputString , regexString , replacementString |
| ) |
Replaces each substring that matches a regular expression. For details, see the Java String.replaceAll() method. If any parameter is null (except optional flagsString parameter), the result is null.
Flags values are limited to 'i', 'c', 'n', 'm'. Other symbols cause exception. Multiple symbols could be used in one flagsString parameter (like 'im'). Later flags override first ones, for example 'ic' is equivalent to case sensitive matching 'c'.
'i' enables case insensitive matching (Pattern.CASE_INSENSITIVE)
'c' disables case insensitive matching (Pattern.CASE_INSENSITIVE)
'n' allows the period to match the newline character (Pattern.DOTALL)
'm' enables multiline mode (Pattern.MULTILINE)
Example:
REGEXP_REPLACE('Hello World', ' +', ' ')
REGEXP_REPLACE('Hello WWWWorld', 'w+', 'W', 'i')
REGEXP_LIKE
REGEXP_LIKE ( inputString , regexString |
| ) |
Matches string to a regular expression. For details, see the Java Matcher.find() method. If any parameter is null (except optional flagsString parameter), the result is null.
Flags values are limited to 'i', 'c', 'n', 'm'. Other symbols cause exception. Multiple symbols could be used in one flagsString parameter (like 'im'). Later flags override first ones, for example 'ic' is equivalent to case sensitive matching 'c'.
'i' enables case insensitive matching (Pattern.CASE_INSENSITIVE)
'c' disables case insensitive matching (Pattern.CASE_INSENSITIVE)
'n' allows the period to match the newline character (Pattern.DOTALL)
'm' enables multiline mode (Pattern.MULTILINE)
Example:
REGEXP_LIKE('Hello World', '[A-Z ]*', 'i')
REGEXP_SUBSTR
REGEXP_SUBSTR ( inputString , regexString |
| ) |
Matches string to a regular expression and returns the matched substring. For details, see the java.util.regex.Pattern and related functionality.
The parameter position specifies where in inputString the match should start. Occurrence indicates which occurrence of pattern in inputString to search for.
Flags values are limited to 'i', 'c', 'n', 'm'. Other symbols cause exception. Multiple symbols could be used in one flagsString parameter (like 'im'). Later flags override first ones, for example 'ic' is equivalent to case sensitive matching 'c'.
'i' enables case insensitive matching (Pattern.CASE_INSENSITIVE)
'c' disables case insensitive matching (Pattern.CASE_INSENSITIVE)
'n' allows the period to match the newline character (Pattern.DOTALL)
'm' enables multiline mode (Pattern.MULTILINE)
If the pattern has groups, the group parameter can be used to specify which group to return.
Example:
REGEXP_SUBSTR('2020-10-01', '\d{4}')
REGEXP_SUBSTR('2020-10-01', '(\d{4})-(\d{2})-(\d{2})', 1, 1, NULL, 2)
REPEAT
Returns a string repeated some number of times.
Example:
REPEAT(NAME || ' ', 10)
REPLACE
REPLACE ( string , searchString |
| ) |
Replaces all occurrences of a search string in a text with another string. If no replacement is specified, the search string is removed from the original string. If any parameter is null, the result is null.
Example:
REPLACE(NAME, ' ')
SOUNDEX
SOUNDEX ( string ) |
Returns a four character upper-case code representing the sound of a string as pronounced in English. This method returns a string, or null if parameter is null. See https://en.wikipedia.org/wiki/Soundex for more information.
Example:
SOUNDEX(NAME)
SPACE
SPACE ( int ) |
Returns a string consisting of a number of spaces.
Example:
SPACE(80)
STRINGDECODE
STRINGDECODE ( string ) |
Converts a encoded string using the Java string literal encoding format. Special characters are \b, \t, \n, \f, \r, \", \\, \<octal>, \u<unicode>. This method returns a string.
Example:
CALL STRINGENCODE(STRINGDECODE('Lines 1\nLine 2'))
STRINGENCODE
STRINGENCODE ( string ) |
Encodes special characters in a string using the Java string literal encoding format. Special characters are \b, \t, \n, \f, \r, \", \\, \<octal>, \u<unicode>. This method returns a string.
Example:
CALL STRINGENCODE(STRINGDECODE('Lines 1\nLine 2'))
STRINGTOUTF8
STRINGTOUTF8 ( string ) |
Encodes a string to a byte array using the UTF8 encoding format. This method returns bytes.
Example:
CALL UTF8TOSTRING(STRINGTOUTF8('This is a test'))
SUBSTRING
Returns a substring of a string starting at a position. If the start index is negative, then the start index is relative to the end of the string. The length is optional.
Example:
CALL SUBSTRING('[Hello]' FROM 2 FOR 5);
CALL SUBSTRING('hour' FROM 2);
UTF8TOSTRING
UTF8TOSTRING ( bytes ) |
Decodes a byte array in the UTF8 format to a string.
Example:
CALL UTF8TOSTRING(STRINGTOUTF8('This is a test'))
QUOTE_IDENT
QUOTE_IDENT ( string ) |
Quotes the specified identifier. Identifier is surrounded by double quotes. If identifier contains double quotes they are repeated twice.
Example:
QUOTE_IDENT('Column 1')
XMLATTR
XMLATTR ( nameString , valueString ) |
Creates an XML attribute element of the form name=value. The value is encoded as XML text. This method returns a string.
Example:
CALL XMLNODE('a', XMLATTR('href', 'https://h2database.com'))
XMLNODE
XMLNODE ( elementString |
| ) |
Create an XML node element. An empty or null attribute string means no attributes are set. An empty or null content string means the node is empty. The content is indented by default if it contains a newline. This method returns a string.
Example:
CALL XMLNODE('a', XMLATTR('href', 'https://h2database.com'), 'H2')
XMLCOMMENT
XMLCOMMENT ( commentString ) |
Creates an XML comment. Two dashes (--) are converted to - -. This method returns a string.
Example:
CALL XMLCOMMENT('Test')
XMLCDATA
XMLCDATA ( valueString ) |
Creates an XML CDATA element. If the value contains ]]>, an XML text element is created instead. This method returns a string.
Example:
CALL XMLCDATA('data')
XMLSTARTDOC
XMLSTARTDOC ( ) |
Returns the XML declaration. The result is always <?xml version=1.0?>.
Example:
CALL XMLSTARTDOC()
XMLTEXT
XMLTEXT ( valueString |
| ) |
Creates an XML text element. If enabled, newline and linefeed is converted to an XML entity (&#). This method returns a string.
Example:
CALL XMLTEXT('test')
TO_CHAR
TO_CHAR ( value |
| ) |
Oracle-compatible TO_CHAR function that can format a timestamp, a number, or text.
Example:
CALL TO_CHAR(TIMESTAMP '2010-01-01 00:00:00', 'DD MON, YYYY')
TRANSLATE
TRANSLATE ( value , searchString , replacementString ) |
Oracle-compatible TRANSLATE function that replaces a sequence of characters in a string with another set of characters.
Example:
CALL TRANSLATE('Hello world', 'eo', 'EO')
Time and Date Functions
CURRENT_DATE
CURRENT_DATE
Returns the current date.
These functions return the same value within a transaction (default) or within a command depending on database mode.
SET TIME ZONE command reevaluates the value for these functions using the same original UTC timestamp of transaction.
Example:
CURRENT_DATE
CURRENT_TIME
CURRENT_TIME |
|
Returns the current time with time zone. If fractional seconds precision is specified it should be from 0 to 9, 0 is default. The specified value can be used only to limit precision of a result. The actual maximum available precision depends on operating system and JVM and can be 3 (milliseconds) or higher. Higher precision is not available before Java 9.
This function returns the same value within a transaction (default) or within a command depending on database mode.
SET TIME ZONE command reevaluates the value for this function using the same original UTC timestamp of transaction.
Example:
CURRENT_TIME
CURRENT_TIME(9)
CURRENT_TIMESTAMP
CURRENT_TIMESTAMP |
|
Returns the current timestamp with time zone. Time zone offset is set to a current time zone offset. If fractional seconds precision is specified it should be from 0 to 9, 6 is default. The specified value can be used only to limit precision of a result. The actual maximum available precision depends on operating system and JVM and can be 3 (milliseconds) or higher. Higher precision is not available before Java 9.
This function returns the same value within a transaction (default) or within a command depending on database mode.
SET TIME ZONE command reevaluates the value for this function using the same original UTC timestamp of transaction.
Example:
CURRENT_TIMESTAMP
CURRENT_TIMESTAMP(9)
LOCALTIME
LOCALTIME |
|
Returns the current time without time zone. If fractional seconds precision is specified it should be from 0 to 9, 0 is default. The specified value can be used only to limit precision of a result. The actual maximum available precision depends on operating system and JVM and can be 3 (milliseconds) or higher. Higher precision is not available before Java 9.
These functions return the same value within a transaction (default) or within a command depending on database mode.
SET TIME ZONE command reevaluates the value for these functions using the same original UTC timestamp of transaction.
Example:
LOCALTIME
LOCALTIME(9)
LOCALTIMESTAMP
LOCALTIMESTAMP |
|
Returns the current timestamp without time zone. If fractional seconds precision is specified it should be from 0 to 9, 6 is default. The specified value can be used only to limit precision of a result. The actual maximum available precision depends on operating system and JVM and can be 3 (milliseconds) or higher. Higher precision is not available before Java 9.
The returned value has date and time without time zone information. If time zone has DST transitions the returned values are ambiguous during transition from DST to normal time. For absolute timestamps use the CURRENT_TIMESTAMP function and TIMESTAMP WITH TIME ZONE data type.
These functions return the same value within a transaction (default) or within a command depending on database mode.
SET TIME ZONE reevaluates the value for these functions using the same original UTC timestamp of transaction.
Example:
LOCALTIMESTAMP
LOCALTIMESTAMP(9)
DATEADD
|
|
Adds units to a date-time value. The datetimeField indicates the unit. Use negative values to subtract units. addIntLong may be a long value when manipulating milliseconds, microseconds, or nanoseconds otherwise its range is restricted to int. This method returns a value with the same type as specified value if unit is compatible with this value. If specified field is a HOUR, MINUTE, SECOND, MILLISECOND, etc and value is a DATE value DATEADD returns combined TIMESTAMP. Fields DAY, MONTH, YEAR, WEEK, etc are not allowed for TIME values. Fields TIMEZONE_HOUR, TIMEZONE_MINUTE, and TIMEZONE_SECOND are only allowed for TIMESTAMP WITH TIME ZONE values.
Example:
DATEADD(MONTH, 1, DATE '2001-01-31')
DATEDIFF
|
|
Returns the number of crossed unit boundaries between two date/time values. This method returns a long. The datetimeField indicates the unit. Only TIMEZONE_HOUR, TIMEZONE_MINUTE, and TIMEZONE_SECOND fields use the time zone offset component. With all other fields if date/time values have time zone offset component it is ignored.
Example:
DATEDIFF(YEAR, T1.CREATED, T2.CREATED)
DATE_TRUNC
DATE_TRUNC ( datetimeField , dateAndTime ) |
Truncates the specified date-time value to the specified field.
Example:
DATE_TRUNC(DAY, TIMESTAMP '2010-01-03 10:40:00');
LAST_DAY
| |||
timestamp | |||
timestampWithTimeZone | |||
|
Returns the last day of the month that contains the specified date-time value. This function returns a date.
Example:
LAST_DAY(DAY, DATE '2020-02-05');
DAYNAME
DAYNAME ( dateAndTime ) |
Returns the name of the day (in English).
Example:
DAYNAME(CREATED)
DAY_OF_MONTH
DAY_OF_MONTH ( |
| ) |
Returns the day of the month (1-31).
This function is deprecated, use EXTRACT instead of it.
Example:
DAY_OF_MONTH(CREATED)
DAY_OF_WEEK
DAY_OF_WEEK ( dateAndTime ) |
Returns the day of the week (1-7), locale-specific.
This function is deprecated, use EXTRACT instead of it.
Example:
DAY_OF_WEEK(CREATED)
ISO_DAY_OF_WEEK
ISO_DAY_OF_WEEK ( dateAndTime ) |
Returns the ISO day of the week (1 means Monday).
This function is deprecated, use EXTRACT instead of it.
Example:
ISO_DAY_OF_WEEK(CREATED)
DAY_OF_YEAR
DAY_OF_YEAR ( |
| ) |
Returns the day of the year (1-366).
This function is deprecated, use EXTRACT instead of it.
Example:
DAY_OF_YEAR(CREATED)
EXTRACT
EXTRACT ( datetimeField FROM |
| ) |
Returns a value of the specific time unit from a date/time value. This method returns a numeric value with EPOCH field and an int for all other fields.
Example:
EXTRACT(SECOND FROM CURRENT_TIMESTAMP)
FORMATDATETIME
Formats a date, time or timestamp as a string. The most important format characters are: y year, M month, d day, H hour, m minute, s second. For details of the format, see java.time.format.DateTimeFormatter. Allowed format characters depend on data type of passed date/time value.
If timeZoneString is specified, it is used in formatted string if formatString has time zone. For TIME and TIME WITH TIME ZONE values the specified time zone must have a fixed offset.
If TIME WITH TIME ZONE is passed and timeZoneString is specified, the time is converted to the specified time zone offset and its UTC value is preserved. If TIMESTAMP WITH TIME ZONE is passed and timeZoneString is specified, the timestamp is converted to the specified time zone and its UTC value is preserved.
This method returns a string.
See also cast specification.
Example:
CALL FORMATDATETIME(TIMESTAMP '2001-02-03 04:05:06',
'EEE, d MMM yyyy HH:mm:ss z', 'en', 'GMT')
HOUR
HOUR ( |
| ) |
Returns the hour (0-23) from a date/time value.
This function is deprecated, use EXTRACT instead of it.
Example:
HOUR(CREATED)
MINUTE
MINUTE ( |
| ) |
Returns the minute (0-59) from a date/time value.
This function is deprecated, use EXTRACT instead of it.
Example:
MINUTE(CREATED)
MONTH
MONTH ( |
| ) |
Returns the month (1-12) from a date/time value.
This function is deprecated, use EXTRACT instead of it.
Example:
MONTH(CREATED)
MONTHNAME
MONTHNAME ( dateAndTime ) |
Returns the name of the month (in English).
Example:
MONTHNAME(CREATED)
PARSEDATETIME
Parses a string and returns a TIMESTAMP WITH TIME ZONE value. The most important format characters are: y year, M month, d day, H hour, m minute, s second. For details of the format, see java.time.format.DateTimeFormatter.
If timeZoneString is specified, it is used as default.
See also cast specification.
Example:
CALL PARSEDATETIME('Sat, 3 Feb 2001 03:05:06 GMT',
'EEE, d MMM yyyy HH:mm:ss z', 'en', 'GMT')
QUARTER
QUARTER ( dateAndTime ) |
Returns the quarter (1-4) from a date/time value.
This function is deprecated, use EXTRACT instead of it.
Example:
QUARTER(CREATED)
SECOND
SECOND ( dateAndTime ) |
Returns the second (0-59) from a date/time value.
This function is deprecated, use EXTRACT instead of it.
Example:
SECOND(CREATED|interval)
WEEK
WEEK ( dateAndTime ) |
Returns the week (1-53) from a date/time value.
This function is deprecated, use EXTRACT instead of it.
This function uses the current system locale.
Example:
WEEK(CREATED)
ISO_WEEK
ISO_WEEK ( dateAndTime ) |
Returns the ISO week (1-53) from a date/time value.
This function is deprecated, use EXTRACT instead of it.
This function uses the ISO definition when first week of year should have at least four days and week is started with Monday.
Example:
ISO_WEEK(CREATED)
YEAR
YEAR ( |
| ) |
Returns the year from a date/time value.
This function is deprecated, use EXTRACT instead of it.
Example:
YEAR(CREATED)
ISO_YEAR
ISO_YEAR ( dateAndTime ) |
Returns the ISO week year from a date/time value.
This function is deprecated, use EXTRACT instead of it.
Example:
ISO_YEAR(CREATED)
System Functions
ABORT_SESSION
ABORT_SESSION ( sessionInt ) |
Cancels the currently executing statement of another session. Closes the session and releases the allocated resources. Returns true if the session was closed, false if no session with the given id was found.
If a client was connected while its session was aborted it will see an error.
Admin rights are required to execute this command.
Example:
CALL ABORT_SESSION(3)
ARRAY_GET
ARRAY_GET ( arrayExpression , indexExpression ) |
Returns element at the specified 1-based index from an array.
This function is deprecated, use [array element reference](https://www.h2database.com/html/grammar.html#array_element_reference) instead of it.
Returns NULL if array or index is NULL.
Example:
CALL ARRAY_GET(ARRAY['Hello', 'World'], 2)
CARDINALITY
| ( arrayExpression ) |
Returns the length of an array or JSON array. Returns NULL if the specified array is NULL.
Example:
CALL CARDINALITY(ARRAY['Hello', 'World'])
CALL CARDINALITY(JSON '[1, 2, 3]')
ARRAY_CONTAINS
ARRAY_CONTAINS ( arrayExpression , value ) |
Returns a boolean TRUE if the array contains the value or FALSE if it does not contain it. Returns NULL if the specified array is NULL.
Example:
CALL ARRAY_CONTAINS(ARRAY['Hello', 'World'], 'Hello')
ARRAY_CAT
ARRAY_CAT ( arrayExpression , arrayExpression ) |
Returns the concatenation of two arrays.
This function is deprecated, use || instead of it.
Returns NULL if any parameter is NULL.
Example:
CALL ARRAY_CAT(ARRAY[1, 2], ARRAY[3, 4])
ARRAY_APPEND
ARRAY_APPEND ( arrayExpression , value ) |
Append an element to the end of an array.
This function is deprecated, use || instead of it.
Returns NULL if any parameter is NULL.
Example:
CALL ARRAY_APPEND(ARRAY[1, 2], 3)
ARRAY_MAX_CARDINALITY
ARRAY_MAX_CARDINALITY ( arrayExpression ) |
Returns the maximum allowed array cardinality (length) of the declared data type of argument.
Example:
SELECT ARRAY_MAX_CARDINALITY(COL1) FROM TEST FETCH FIRST ROW ONLY;
TRIM_ARRAY
TRIM_ARRAY ( arrayExpression , int ) |
Removes the specified number of elements from the end of the array.
Returns NULL if second parameter is NULL or if first parameter is NULL and second parameter is not negative. Throws exception if second parameter is negative or larger than number of elements in array. Otherwise returns the truncated array.
Example:
CALL TRIM_ARRAY(ARRAY[1, 2, 3, 4], 1)
ARRAY_SLICE
ARRAY_SLICE ( arrayExpression , lowerBoundInt , upperBoundInt ) |
Returns elements from the array as specified by the lower and upper bound parameters. Both parameters are inclusive and the first element has index 1, i.e. ARRAY_SLICE(a, 2, 2) has only the second element. Returns NULL if any parameter is NULL or if an index is out of bounds.
Example:
CALL ARRAY_SLICE(ARRAY[1, 2, 3, 4], 1, 3)
AUTOCOMMIT
AUTOCOMMIT ( ) |
Returns true if auto commit is switched on for this session.
Example:
AUTOCOMMIT()
CANCEL_SESSION
CANCEL_SESSION ( sessionInt ) |
Cancels the currently executing statement of another session. Returns true if the statement was canceled, false if the session is closed or no statement is currently executing.
Admin rights are required to execute this command.
Example:
CANCEL_SESSION(3)
CASEWHEN Function
Returns 'aValue' if the boolean expression is true, otherwise 'bValue'.
This function is deprecated, use CASE instead of it.
Example:
CASEWHEN(ID=1, 'A', 'B')
COALESCE
Returns the first value that is not null.
Example:
COALESCE(A, B, C)
CONVERT
CONVERT ( value , dataTypeOrDomain ) |
Converts a value to another data type.
This function is deprecated, use CAST instead of it.
Example:
CONVERT(NAME, INT)
CURRVAL
CURRVAL ( |
| sequenceString ) |
Returns the latest generated value of the sequence for the current session. Current value may only be requested after generation of the sequence value in the current session. This method exists only for compatibility, when it isn't required use CURRENT VALUE FOR sequenceName instead. If the schema name is not set, the current schema is used. When sequence is not found, the uppercase name is also checked. This method returns a long.
Example:
CURRVAL('TEST_SEQ')
CSVWRITE
CSVWRITE ( fileNameString , queryString |
| ) |
Writes a CSV (comma separated values). The file is overwritten if it exists. If only a file name is specified, it will be written to the current working directory. For each parameter, NULL means the default value should be used. The default charset is the default value for this system, and the default field separator is a comma.
The values are converted to text using the default string representation; if another conversion is required you need to change the select statement accordingly. The parameter nullString is used when writing NULL (by default nothing is written when NULL appears). The default line separator is the default value for this system (system property line.separator).
The returned value is the number or rows written. Admin rights are required to execute this command.
Example:
CALL CSVWRITE('data/test.csv', 'SELECT * FROM TEST');
CALL CSVWRITE('data/test2.csv', 'SELECT * FROM TEST', 'charset=UTF-8 fieldSeparator=|');
-- Write a tab-separated file
CALL CSVWRITE('data/test.tsv', 'SELECT * FROM TEST', 'charset=UTF-8 fieldSeparator=' || CHAR(9));
CURRENT_SCHEMA
CURRENT_SCHEMA | |||
|
Returns the name of the default schema for this session.
Example:
CALL CURRENT_SCHEMA
CURRENT_CATALOG
CURRENT_CATALOG | |||
|
Returns the name of the database.
Example:
CALL CURRENT_CATALOG
DATABASE_PATH
DATABASE_PATH ( ) |
Returns the directory of the database files and the database name, if it is file based. Returns NULL otherwise.
Example:
CALL DATABASE_PATH();
DATA_TYPE_SQL
Returns SQL representation of data type of the specified constant, domain, table column, routine result or argument.
For constants object type is 'CONSTANT' and type identifier is the value of INFORMATION_SCHEMA.CONSTANTS.DTD_IDENTIFIER.
For domains object type is 'DOMAIN' and type identifier is the value of INFORMATION_SCHEMA.DOMAINS.DTD_IDENTIFIER.
For columns object type is 'TABLE' and type identifier is the value of INFORMATION_SCHEMA.COLUMNS.DTD_IDENTIFIER.
For routines object name is the value of INFORMATION_SCHEMA.ROUTINES.SPECIFIC_NAME, object type is 'ROUTINE', and type identifier is the value of INFORMATION_SCHEMA.ROUTINES.DTD_IDENTIFIER for data type of the result and the value of INFORMATION_SCHEMA.PARAMETERS.DTD_IDENTIFIER for data types of arguments. Aggregate functions aren't supported by this function, because their data type isn't statically known.
This function returns NULL if any argument is NULL, object type is not valid, or object isn't found.
Example:
DATA_TYPE_SQL('PUBLIC', 'C', 'CONSTANT', 'TYPE')
DATA_TYPE_SQL('PUBLIC', 'D', 'DOMAIN', 'TYPE')
DATA_TYPE_SQL('PUBLIC', 'T', 'TABLE', '1')
DATA_TYPE_SQL('PUBLIC', 'R_1', 'ROUTINE', 'RESULT')
DATA_TYPE_SQL('PUBLIC', 'R_1', 'ROUTINE', '1')
COALESCE(
QUOTE_IDENT(DOMAIN_SCHEMA) || '.' || QUOTE_IDENT(DOMAIN_NAME),
DATA_TYPE_SQL(TABLE_SCHEMA, TABLE_NAME, 'TABLE', DTD_IDENTIFIER))
DB_OBJECT_ID
DB_OBJECT_ID ( |
| ) |
Returns internal identifier of the specified database object as integer value or NULL if object doesn't exist.
Admin rights are required to execute this function.
Example:
CALL DB_OBJECT_ID('ROLE', 'MANAGER');
CALL DB_OBJECT_ID('TABLE', 'PUBLIC', 'MY_TABLE');
DB_OBJECT_SQL
DB_OBJECT_SQL ( |
| ) |
Returns internal SQL definition of the specified database object or NULL if object doesn't exist or it is a system object without SQL definition.
This function should not be used to analyze structure of the object by machine code. Internal SQL representation may contain undocumented non-standard clauses and may be different in different versions of H2. Objects are described in the INFORMATION_SCHEMA in machine-readable way.
Admin rights are required to execute this function.
Example:
CALL DB_OBJECT_SQL('ROLE', 'MANAGER');
CALL DB_OBJECT_SQL('TABLE', 'PUBLIC', 'MY_TABLE');
DB_OBJECT_SIZE
DB_OBJECT_SIZE ( |
| , schemaNameString , objectNameString ) |
Returns the approximate amount of space used by the specified table (excluding its indexes) or index. Only size of version used by the current transaction is estimated. Size of large LOBs currently is not included into estimation. This function may be expensive since it has to load every page in the table or index. Use DB_OBJECT_APPROXIMATE_SIZE for a faster coarse approximation.
Example:
CALL DB_OBJECT_SIZE('TABLE', 'PUBLIC', 'MY_TABLE');
DB_OBJECT_TOTAL_SIZE
DB_OBJECT_TOTAL_SIZE ( ' TABLE ' , schemaNameString , objectNameString ) |
Returns the approximate amount of space used by the specified table and all its indexes. Only size of version used by the current transaction is estimated. Size of large LOBs currently is not included into estimation. This function may be expensive since it has to load every page in the table and its indexes. Use DB_OBJECT_APPROXIMATE_TOTAL_SIZE for a faster coarse approximation.
Example:
CALL DB_OBJECT_TOTAL_SIZE('TABLE', 'PUBLIC', 'MY_TABLE');
DB_OBJECT_APPROXIMATE_SIZE
DB_OBJECT_APPROXIMATE_SIZE ( |
| , schemaNameString , objectNameString ) |
Returns the coarse approximate amount of space used by the specified table (excluding its indexes) or index. Only size of version used by the current transaction is estimated. Size of large LOBs currently is not included into estimation.
Example:
CALL DB_OBJECT_APPROXIMATE_SIZE('TABLE', 'PUBLIC', 'MY_TABLE');
DB_OBJECT_APPROXIMATE_TOTAL_SIZE
DB_OBJECT_APPROXIMATE_TOTAL_SIZE ( ' TABLE ' , schemaNameString , objectNameString ) |
Returns the coarse approximate amount of space used by the specified table and all its indexes. Only size of version used by the current transaction is estimated. Size of large LOBs currently is not included into estimation.
Example:
CALL DB_OBJECT_APPROXIMATE_TOTAL_SIZE('TABLE', 'PUBLIC', 'MY_TABLE');
DECODE
Returns the first matching value. NULL is considered to match NULL. If no match was found, then NULL or the last parameter (if the parameter count is even) is returned. This function is provided for Oracle compatibility, use CASE instead of it.
Example:
CALL DECODE(RAND()>0.5, 0, 'Red', 1, 'Black');
DISK_SPACE_USED
DISK_SPACE_USED ( tableNameString ) |
Returns the approximate amount of space used by the table specified. Only size of version used by the current transaction is estimated. Does not currently take into account indexes or LOB's. This function may be expensive since it has to load every page in the table. This function is deprecated, use DB_OBJECT_SIZE instead of it.
Example:
CALL DISK_SPACE_USED('my_table');
SIGNAL
SIGNAL ( sqlStateString , messageString ) |
Throw an SQLException with the passed SQLState and reason.
Example:
CALL SIGNAL('23505', 'Duplicate user ID: ' || user_id);
ESTIMATED_ENVELOPE
ESTIMATED_ENVELOPE ( tableNameString , columnNameString ) |
Returns the estimated minimum bounding box that encloses all specified GEOMETRY values. Only 2D coordinate plane is supported. NULL values are ignored. Column must have a spatial index. This function is fast, but estimation may include uncommitted data (including data from other transactions), may return approximate bounds, or be different with actual value due to other reasons. Use with caution. If estimation is not available this function returns NULL. For accurate and reliable result use ESTIMATE aggregate function instead.
Example:
CALL ESTIMATED_ENVELOPE('MY_TABLE', 'GEOMETRY_COLUMN');
FILE_READ
FILE_READ ( fileNameString |
| ) |
Returns the contents of a file. If only one parameter is supplied, the data are returned as a BLOB. If two parameters are used, the data is returned as a CLOB (text). The second parameter is the character set to use, NULL meaning the default character set for this system.
File names and URLs are supported. To read a stream from the classpath, use the prefix classpath:.
Admin rights are required to execute this command.
Example:
SELECT LENGTH(FILE_READ('~/.h2.server.properties')) LEN;
SELECT FILE_READ('http://localhost:8182/stylesheet.css', NULL) CSS;
FILE_WRITE
FILE_WRITE ( blobValue , fileNameString ) |
Write the supplied parameter into a file. Return the number of bytes written.
Write access to folder, and admin rights are required to execute this command.
Example:
SELECT FILE_WRITE('Hello world', '/tmp/hello.txt')) LEN;
GREATEST
Returns the largest value or NULL if any value is NULL or the largest value cannot be determined. For example, ROW (NULL, 1) is neither equal to nor smaller than nor larger than ROW (1, 1). If IGNORE NULLS is specified, NULL values are ignored.
Example:
CALL GREATEST(1, 2, 3);
LEAST
Returns the smallest value or NULL if any value is NULL or the smallest value cannot be determined. For example, ROW (NULL, 1) is neither equal to nor smaller than nor larger than ROW (1, 1). If IGNORE NULLS is specified, NULL values are ignored.
Example:
CALL LEAST(1, 2, 3);
LOCK_MODE
LOCK_MODE ( ) |
Returns the current lock mode. See SET LOCK_MODE. This method returns an int.
Example:
CALL LOCK_MODE();
LOCK_TIMEOUT
LOCK_TIMEOUT ( ) |
Returns the lock timeout of the current session (in milliseconds).
Example:
LOCK_TIMEOUT()
MEMORY_FREE
MEMORY_FREE ( ) |
Returns the free memory in KB (where 1024 bytes is a KB). This method returns a long. The garbage is run before returning the value. Admin rights are required to execute this command.
Example:
MEMORY_FREE()
MEMORY_USED
MEMORY_USED ( ) |
Returns the used memory in KB (where 1024 bytes is a KB). This method returns a long. The garbage is run before returning the value. Admin rights are required to execute this command.
Example:
MEMORY_USED()
NEXTVAL
NEXTVAL ( |
| sequenceString ) |
Increments the sequence and returns its value. The current value of the sequence and the last identity in the current session are updated with the generated value. Used values are never re-used, even when the transaction is rolled back. This method exists only for compatibility, it's recommended to use the standard NEXT VALUE FOR sequenceName instead. If the schema name is not set, the current schema is used. When sequence is not found, the uppercase name is also checked. This method returns a long.
Example:
NEXTVAL('TEST_SEQ')
NULLIF
Returns NULL if 'a' is equal to 'b', otherwise 'a'.
Example:
NULLIF(A, B)
A / NULLIF(B, 0)
NVL2
If the test value is null, then 'b' is returned. Otherwise, 'a' is returned. The data type of the returned value is the data type of 'a' if this is a text type.
This function is provided for Oracle compatibility, use CASE or COALESCE instead of it.
Example:
NVL2(X, 'not null', 'null')
READONLY
READONLY ( ) |
Returns true if the database is read-only.
Example:
READONLY()
ROWNUM
ROWNUM ( ) |
Returns the number of the current row. This method returns a long value. It is supported for SELECT statements, as well as for DELETE and UPDATE. The first row has the row number 1, and is calculated before ordering and grouping the result set, but after evaluating index conditions (even when the index conditions are specified in an outer query). Use the ROW_NUMBER() OVER () function to get row numbers after grouping or in specified order.
Example:
SELECT ROWNUM(), * FROM TEST;
SELECT ROWNUM(), * FROM (SELECT * FROM TEST ORDER BY NAME);
SELECT ID FROM (SELECT T.*, ROWNUM AS R FROM TEST T) WHERE R BETWEEN 2 AND 3;
SESSION_ID
SESSION_ID ( ) |
Returns the unique session id number for the current database connection. This id stays the same while the connection is open. This method returns an int. The database engine may re-use a session id after the connection is closed.
Example:
CALL SESSION_ID()
SET
SET ( @variableName , value ) |
Updates a variable with the given value. The new value is returned. When used in a query, the value is updated in the order the rows are read. When used in a subquery, not all rows might be read depending on the query plan. This can be used to implement running totals / cumulative sums.
Example:
SELECT X, SET(@I, COALESCE(@I, 0)+X) RUNNING_TOTAL FROM SYSTEM_RANGE(1, 10)
TRANSACTION_ID
TRANSACTION_ID ( ) |
Returns the current transaction id for this session. This method returns NULL if there is no uncommitted change, or if the database is not persisted. Otherwise a value of the following form is returned: logFileId-position-sessionId. This method returns a string. The value is unique across database restarts (values are not re-used).
Example:
CALL TRANSACTION_ID()
TRUNCATE_VALUE
TRUNCATE_VALUE ( value , precisionInt , forceBoolean ) |
Truncate a value to the required precision. If force flag is set to FALSE fixed precision values are not truncated. The method returns a value with the same data type as the first parameter.
Example:
CALL TRUNCATE_VALUE(X, 10, TRUE);
CURRENT_PATH
CURRENT_PATH
Returns the comma-separated list of quoted schema names where user-defined functions are searched when they are referenced without the schema name.
Example:
CURRENT_PATH
CURRENT_ROLE
CURRENT_ROLE
Returns the name of the PUBLIC role.
Example:
CURRENT_ROLE
CURRENT_USER
CURRENT_USER | ||
SESSION_USER | ||
SYSTEM_USER | ||
USER |
Returns the name of the current user of this session.
Example:
CURRENT_USER
H2VERSION
H2VERSION ( ) |
Returns the H2 version as a String.
Example:
H2VERSION()
JSON Functions
JSON_OBJECT
JSON_OBJECT ( |
|
|
|
)
Returns a JSON object constructed from the specified properties. If ABSENT ON NULL is specified properties with NULL value are not included in the object. If WITH UNIQUE KEYS is specified the constructed object is checked for uniqueness of keys, nested objects, if any, are checked too.
Example:
JSON_OBJECT('id': 100, 'name': 'Joe', 'groups': '[2,5]' FORMAT JSON);
JSON_ARRAY
Returns a JSON array constructed from the specified values or from the specified single-column subquery. If NULL ON NULL is specified NULL values are included in the array.
Example:
JSON_ARRAY(10, 15, 20);
JSON_ARRAY(JSON_DATA_A FORMAT JSON, JSON_DATA_B FORMAT JSON);
JSON_ARRAY((SELECT J FROM PROPS) FORMAT JSON);
Table Functions
CSVREAD
CSVREAD ( fileNameString |
| ) |
Returns the result set of reading the CSV (comma separated values) file. For each parameter, NULL means the default value should be used.
If the column names are specified (a list of column names separated with the fieldSeparator), those are used, otherwise (or if they are set to NULL) the first line of the file is interpreted as the column names. In that case, column names that contain no special characters (only letters, '_', and digits; similar to the rule for Java identifiers) are processed is the same way as unquoted identifiers and therefore case of characters may be changed. Other column names are processed as quoted identifiers and case of characters is preserved. To preserve the case of column names unconditionally use caseSensitiveColumnNames option.
The default charset is the default value for this system, and the default field separator is a comma. Missing unquoted values as well as data that matches nullString is parsed as NULL. All columns are of type VARCHAR.
The BOM (the byte-order-mark) character 0xfeff at the beginning of the file is ignored.
This function can be used like a table: SELECT * FROM CSVREAD(...).
Instead of a file, a URL may be used, for example jar:file:///c:/temp/example.zip!/org/example/nested.csv. To read a stream from the classpath, use the prefix classpath:. To read from HTTP, use the prefix http: (as in a browser).
For performance reason, CSVREAD should not be used inside a join. Instead, import the data first (possibly into a temporary table) and then use the table.
Admin rights are required to execute this command.
Example:
SELECT * FROM CSVREAD('test.csv');
-- Read a file containing the columns ID, NAME with
SELECT * FROM CSVREAD('test2.csv', 'ID|NAME', 'charset=UTF-8 fieldSeparator=|');
SELECT * FROM CSVREAD('data/test.csv', null, 'rowSeparator=;');
-- Read a tab-separated file
SELECT * FROM CSVREAD('data/test.tsv', null, 'rowSeparator=' || CHAR(9));
SELECT "Last Name" FROM CSVREAD('address.csv');
SELECT "Last Name" FROM CSVREAD('classpath:/org/acme/data/address.csv');
LINK_SCHEMA
LINK_SCHEMA ( targetSchemaString , driverString , urlString , |
Creates table links for all tables in a schema. If tables with the same name already exist, they are dropped first. The target schema is created automatically if it does not yet exist. The driver name may be empty if the driver is already loaded. The list of tables linked is returned in the form of a result set. Admin rights are required to execute this command.
Example:
SELECT * FROM LINK_SCHEMA('TEST2', '', 'jdbc:h2:./test2', 'sa', 'sa', 'PUBLIC');
TABLE
Returns the result set. TABLE_DISTINCT removes duplicate rows.
Example:
SELECT * FROM TABLE(V INT = ARRAY[1, 2]);
SELECT * FROM TABLE(ID INT=(1, 2), NAME VARCHAR=('Hello', 'World'));
UNNEST
UNNEST ( arrayExpression , |
| ) |
|
Returns the result set. Number of columns is equal to number of arguments, plus one additional column with row number if WITH ORDINALITY is specified. Number of rows is equal to length of longest specified array. If multiple arguments are specified and they have different length, cells with missing values will contain null values.
Example:
SELECT * FROM UNNEST(ARRAY['a', 'b', 'c']);
SELECT * FROM UNNEST(JSON '["a", "b", "c"]');