org.h2.expression
Class Function

java.lang.Object
  org.h2.expression.Expression
      org.h2.expression.Function

All Implemented Interfaces:

FunctionCall

Direct Known Subclasses:

TableFunction

public class Function
extends Expression
implements FunctionCall

This class implements most built-in functions of this database.

Field Summary

static int	ABS
static int	ACOS
protected Expression[]	args
static int	ARRAY_GET
static int	ARRAY_LENGTH
static int	ASCII
static int	ASIN
static int	ATAN
static int	ATAN2
static int	AUTOCOMMIT
static int	BIT_LENGTH
static int	BITAND
static int	BITOR
static int	BITXOR
static int	CANCEL_SESSION
static int	CASE
static int	CASEWHEN
static int	CAST
static int	CEILING
static int	CHAR
static int	CHAR_LENGTH
static int	COALESCE
static int	COMPRESS
static int	CONCAT
static int	CONVERT
static int	COS
static int	COT
static int	CSVREAD
static int	CSVWRITE
static int	CURDATE
static int	CURRENT_DATE
static int	CURRENT_TIME
static int	CURRENT_TIMESTAMP
static int	CURRENT_USER
static int	CURRVAL
static int	CURTIME
static int	DATABASE
static int	DATABASE_PATH
static int	DATE_ADD
static int	DATE_DIFF
static int	DAY_NAME
static int	DAY_OF_MONTH
static int	DAY_OF_WEEK
static int	DAY_OF_YEAR
static int	DECRYPT
static int	DEGREES
static int	DIFFERENCE
static int	ENCRYPT
static int	EXP
static int	EXPAND
static int	EXTRACT
static int	FILE_READ
static int	FLOOR
static int	FORMATDATETIME
static int	GREATEST
static int	HASH
static int	HEXTORAW
static int	HOUR
static int	IDENTITY
static int	IFNULL
static int	INSERT
static int	INSTR
static int	ISO_DAY_OF_WEEK
static int	ISO_WEEK
static int	ISO_YEAR
static int	LCASE
static int	LEAST
static int	LEFT
static int	LENGTH
static int	LINK_SCHEMA
static int	LOCATE
static int	LOCK_MODE
static int	LOCK_TIMEOUT
static int	LOG
static int	LOG10
static int	LOWER
static int	LPAD
static int	LTRIM
static int	MEMORY_FREE
static int	MEMORY_USED
static int	MINUTE
static int	MOD
static int	MONTH
static int	MONTH_NAME
static int	NEXTVAL
static int	NOW
static int	NULLIF
static int	OCTET_LENGTH
static int	PARSEDATETIME
static int	PI
static int	POSITION
static int	POWER
static int	QUARTER
static int	RADIANS
static int	RAND
static int	RANDOM_UUID
static int	RAWTOHEX
static int	READONLY
static int	REGEXP_REPLACE
static int	REPEAT
static int	REPLACE
static int	RIGHT
static int	ROUND
static int	ROUNDMAGIC
static int	RPAD
static int	RTRIM
static int	SCHEMA
static int	SCOPE_IDENTITY
static int	SECOND
static int	SECURE_RAND
static int	SESSION_ID
static int	SET
static int	SIGN
static int	SIN
static int	SOUNDEX
static int	SPACE
static int	SQRT
static int	STRINGDECODE
static int	STRINGENCODE
static int	STRINGTOUTF8
static int	SUBSTR
static int	SUBSTRING
static int	TABLE
static int	TABLE_DISTINCT
static int	TAN
static int	TRANSACTION_ID
static int	TRIM
static int	TRUNCATE
static int	UCASE
static int	UPPER
static int	USER
static int	UTF8TOSTRING
static int	WEEK
static int	XMLATTR
static int	XMLCDATA
static int	XMLCOMMENT
static int	XMLNODE
static int	XMLSTARTDOC
static int	XMLTEXT
static int	YEAR
static int	ZERO

Constructor Summary

protected

Function(Database database, org.h2.expression.FunctionInfo info)

Method Summary

protected void	checkParameterCount(int len) Check if the parameter count is correct.
void	doneWithParameters() This method is called after all the parameters have been set.
Expression[]	getArgs() Get the function arguments.
int	getCost() Estimate the cost to process the expression.
int	getDisplaySize() Get the display size of this expression.
static Function	getFunction(Database database, java.lang.String name) Get an instance of the given function for this database.
static org.h2.expression.FunctionInfo	getFunctionInfo(java.lang.String name) Get the function info object for this function, or null if there is no such function.
int	getFunctionType()
java.lang.String	getName() Get the name of the function.
int	getParameterCount() Get the number of parameters.
long	getPrecision() Get the precision of this expression.
int	getScale() Get the scale of this expression.
java.lang.String	getSQL() Get the SQL statement of this expression.
int	getType() Return the data type.
Value	getValue(Session session) Return the resulting value for the current row.
ValueResultSet	getValueForColumnList(Session session, Expression[] argList) Get an empty result set with the column names set.
static boolean	isDatePart(java.lang.String part) Check if a given string is a valid date part string.
boolean	isDeterministic() Whether the function always returns the same result for the same parameters.
boolean	isEverything(ExpressionVisitor visitor) Check if this expression and all sub-expressions can fulfill a criteria.
void	mapColumns(ColumnResolver resolver, int level) Map the columns of the resolver to expression columns.
Expression	optimize(Session session) Try to optimize the expression.
void	setDataType(Column col)
void	setDataType(int dataType, long precision, int scale, int displaySize) Set the result data type of this function.
void	setEvaluatable(TableFilter tableFilter, boolean b) Tell the expression columns whether the table filter can return values now.
void	setParameter(int index, Expression param) Set the parameter expression at the given index.
void	updateAggregate(Session session) Update an aggregate value.

Methods inherited from class org.h2.expression.Expression

addFilterConditions, createIndexConditions, getAlias, getBooleanValue, getColumnName, getNonAliasExpression, getNotIfPossible, getNullable, getSchemaName, getTableAlias, getTableName, isAutoIncrement, isConstant, isEverything, isValueSet, isWildcard, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

ABS

public static final int ABS

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ACOS

public static final int ACOS

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ASIN

public static final int ASIN

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ATAN

public static final int ATAN

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ATAN2

public static final int ATAN2

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BITAND

public static final int BITAND

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BITOR

public static final int BITOR

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BITXOR

public static final int BITXOR

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CEILING

public static final int CEILING

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COS

public static final int COS

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COT

public static final int COT

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DEGREES

public static final int DEGREES

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EXP

public static final int EXP

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FLOOR

public static final int FLOOR

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LOG

public static final int LOG

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LOG10

public static final int LOG10

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MOD

public static final int MOD

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PI

public static final int PI

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POWER

public static final int POWER

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RADIANS

public static final int RADIANS

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RAND

public static final int RAND

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ROUND

public static final int ROUND

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ROUNDMAGIC

public static final int ROUNDMAGIC

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SIGN

public static final int SIGN

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SIN

public static final int SIN

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SQRT

public static final int SQRT

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TAN

public static final int TAN

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TRUNCATE

public static final int TRUNCATE

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SECURE_RAND

public static final int SECURE_RAND

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HASH

public static final int HASH

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ENCRYPT

public static final int ENCRYPT

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DECRYPT

public static final int DECRYPT

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COMPRESS

public static final int COMPRESS

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EXPAND

public static final int EXPAND

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ZERO

public static final int ZERO

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RANDOM_UUID

public static final int RANDOM_UUID

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ASCII

public static final int ASCII

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BIT_LENGTH

public static final int BIT_LENGTH

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CHAR

public static final int CHAR

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CHAR_LENGTH

public static final int CHAR_LENGTH

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CONCAT

public static final int CONCAT

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DIFFERENCE

public static final int DIFFERENCE

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HEXTORAW

public static final int HEXTORAW

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INSERT

public static final int INSERT

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INSTR

public static final int INSTR

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LCASE

public static final int LCASE

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LEFT

public static final int LEFT

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LENGTH

public static final int LENGTH

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LOCATE

public static final int LOCATE

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LTRIM

public static final int LTRIM

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OCTET_LENGTH

public static final int OCTET_LENGTH

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RAWTOHEX

public static final int RAWTOHEX

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REPEAT

public static final int REPEAT

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REPLACE

public static final int REPLACE

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RIGHT

public static final int RIGHT

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RTRIM

public static final int RTRIM

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SOUNDEX

public static final int SOUNDEX

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SPACE

public static final int SPACE

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SUBSTR

public static final int SUBSTR

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SUBSTRING

public static final int SUBSTRING

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UCASE

public static final int UCASE

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LOWER

public static final int LOWER

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UPPER

public static final int UPPER

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POSITION

public static final int POSITION

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TRIM

public static final int TRIM

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STRINGENCODE

public static final int STRINGENCODE

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STRINGDECODE

public static final int STRINGDECODE

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STRINGTOUTF8

public static final int STRINGTOUTF8

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UTF8TOSTRING

public static final int UTF8TOSTRING

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XMLATTR

public static final int XMLATTR

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XMLNODE

public static final int XMLNODE

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XMLCOMMENT

public static final int XMLCOMMENT

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XMLCDATA

public static final int XMLCDATA

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XMLSTARTDOC

public static final int XMLSTARTDOC

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XMLTEXT

public static final int XMLTEXT

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REGEXP_REPLACE

public static final int REGEXP_REPLACE

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RPAD

public static final int RPAD

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LPAD

public static final int LPAD

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CURDATE

public static final int CURDATE

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CURTIME

public static final int CURTIME

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DATE_ADD

public static final int DATE_ADD

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DATE_DIFF

public static final int DATE_DIFF

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DAY_NAME

public static final int DAY_NAME

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DAY_OF_MONTH

public static final int DAY_OF_MONTH

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DAY_OF_WEEK

public static final int DAY_OF_WEEK

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DAY_OF_YEAR

public static final int DAY_OF_YEAR

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HOUR

public static final int HOUR

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MINUTE

public static final int MINUTE

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MONTH

public static final int MONTH

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MONTH_NAME

public static final int MONTH_NAME

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NOW

public static final int NOW

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QUARTER

public static final int QUARTER

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SECOND

public static final int SECOND

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WEEK

public static final int WEEK

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YEAR

public static final int YEAR

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CURRENT_DATE

public static final int CURRENT_DATE

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CURRENT_TIME

public static final int CURRENT_TIME

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CURRENT_TIMESTAMP

public static final int CURRENT_TIMESTAMP

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EXTRACT

public static final int EXTRACT

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FORMATDATETIME

public static final int FORMATDATETIME

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PARSEDATETIME

public static final int PARSEDATETIME

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ISO_YEAR

public static final int ISO_YEAR

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ISO_WEEK

public static final int ISO_WEEK

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ISO_DAY_OF_WEEK

public static final int ISO_DAY_OF_WEEK

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DATABASE

public static final int DATABASE

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USER

public static final int USER

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CURRENT_USER

public static final int CURRENT_USER

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IDENTITY

public static final int IDENTITY

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SCOPE_IDENTITY

public static final int SCOPE_IDENTITY

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AUTOCOMMIT

public static final int AUTOCOMMIT

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READONLY

public static final int READONLY

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DATABASE_PATH

public static final int DATABASE_PATH

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LOCK_TIMEOUT

public static final int LOCK_TIMEOUT

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IFNULL

public static final int IFNULL

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CASEWHEN

public static final int CASEWHEN

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CONVERT

public static final int CONVERT

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CAST

public static final int CAST

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COALESCE

public static final int COALESCE

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NULLIF

public static final int NULLIF

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CASE

public static final int CASE

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NEXTVAL

public static final int NEXTVAL

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CURRVAL

public static final int CURRVAL

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ARRAY_GET

public static final int ARRAY_GET

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CSVREAD

public static final int CSVREAD

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CSVWRITE

public static final int CSVWRITE

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MEMORY_FREE

public static final int MEMORY_FREE

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MEMORY_USED

public static final int MEMORY_USED

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LOCK_MODE

public static final int LOCK_MODE

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SCHEMA

public static final int SCHEMA

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SESSION_ID

public static final int SESSION_ID

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ARRAY_LENGTH

public static final int ARRAY_LENGTH

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LINK_SCHEMA

public static final int LINK_SCHEMA

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GREATEST

public static final int GREATEST

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LEAST

public static final int LEAST

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CANCEL_SESSION

public static final int CANCEL_SESSION

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SET

public static final int SET

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TABLE

public static final int TABLE

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TABLE_DISTINCT

public static final int TABLE_DISTINCT

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FILE_READ

public static final int FILE_READ

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TRANSACTION_ID

public static final int TRANSACTION_ID

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args

protected Expression[] args

Constructor Detail

Function

protected Function(Database database,
                   org.h2.expression.FunctionInfo info)

Method Detail

getFunctionInfo

public static org.h2.expression.FunctionInfo getFunctionInfo(java.lang.String name)

Get the function info object for this function, or null if there is no such function.

Parameters:

name - the function name

Returns:

the function info

getFunction

public static Function getFunction(Database database,
                                   java.lang.String name)

Get an instance of the given function for this database. If no function with this name is found, null is returned.

Parameters:

database - the database

name - the function name

Returns:

the function object or null

setParameter

public void setParameter(int index,
                         Expression param)

Set the parameter expression at the given index.

Parameters:

index - the index (0, 1,...)

param - the expression

getValue

public Value getValue(Session session)

Description copied from class: Expression

Return the resulting value for the current row.

Specified by:

getValue in interface FunctionCall

Specified by:

getValue in class Expression

Parameters:

session - the session

Returns:

the result

isDatePart

public static boolean isDatePart(java.lang.String part)

Check if a given string is a valid date part string.

Parameters:

part - the string

Returns:

true if it is

getType

public int getType()

Description copied from class: Expression

Return the data type. The data type may not be known before the optimization phase.

Specified by:

getType in interface FunctionCall

Specified by:

getType in class Expression

Returns:

the type

mapColumns

public void mapColumns(ColumnResolver resolver,
                       int level)

Description copied from class: Expression

Map the columns of the resolver to expression columns.

Specified by:

mapColumns in class Expression

Parameters:

resolver - the column resolver

level - the subquery nesting level

checkParameterCount

protected void checkParameterCount(int len)

Check if the parameter count is correct.

Parameters:

len - the number of parameters set

Throws:

java.sql.SQLException - if the parameter count is incorrect

doneWithParameters

public void doneWithParameters()

This method is called after all the parameters have been set. It checks if the parameter count is correct.

Throws:

java.sql.SQLException - if the parameter count is incorrect.

setDataType

public void setDataType(int dataType,
                        long precision,
                        int scale,
                        int displaySize)

Set the result data type of this function.

Parameters:

dataType - the data type

precision - the precision

scale - the scale

displaySize - the display size

setDataType

public void setDataType(Column col)

optimize

public Expression optimize(Session session)

Description copied from class: Expression

Try to optimize the expression.

Specified by:

optimize in interface FunctionCall

Specified by:

optimize in class Expression

Parameters:

session - the session

Returns:

the optimized expression

setEvaluatable

public void setEvaluatable(TableFilter tableFilter,
                           boolean b)

Description copied from class: Expression

Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.

Specified by:

setEvaluatable in class Expression

Parameters:

tableFilter - the table filter

b - true if the table filter can return value

getScale

public int getScale()

Description copied from class: Expression

Get the scale of this expression.

Specified by:

getScale in class Expression

Returns:

the scale

getPrecision

public long getPrecision()

Description copied from class: Expression

Get the precision of this expression.

Specified by:

getPrecision in class Expression

Returns:

the precision

getDisplaySize

public int getDisplaySize()

Description copied from class: Expression

Get the display size of this expression.

Specified by:

getDisplaySize in class Expression

Returns:

the display size

getSQL

public java.lang.String getSQL()

Description copied from class: Expression

Get the SQL statement of this expression. This may not always be the original SQL statement, specially after optimization.

Specified by:

getSQL in interface FunctionCall

Specified by:

getSQL in class Expression

Returns:

the SQL statement

updateAggregate

public void updateAggregate(Session session)

Description copied from class: Expression

Update an aggregate value. This method is called at statement execution time. It is usually called once for each row, but if the expression is used multiple times (for example in the column list, and as part of the HAVING expression) it is called multiple times - the row counter needs to be used to make sure the internal state is only updated once.

Specified by:

updateAggregate in class Expression

Parameters:

session - the session

getFunctionType

public int getFunctionType()

getName

public java.lang.String getName()

Description copied from interface: FunctionCall

Get the name of the function.

Specified by:

getName in interface FunctionCall

Returns:

the name

getParameterCount

public int getParameterCount()

Description copied from interface: FunctionCall

Get the number of parameters.

Specified by:

getParameterCount in interface FunctionCall

Returns:

the number of parameters

getValueForColumnList

public ValueResultSet getValueForColumnList(Session session,
                                            Expression[] argList)

Description copied from interface: FunctionCall

Get an empty result set with the column names set.

Specified by:

getValueForColumnList in interface FunctionCall

Parameters:

session - the session

argList - the argument list (some arguments may be null)

Returns:

the empty result set

getArgs

public Expression[] getArgs()

Description copied from interface: FunctionCall

Get the function arguments.

Specified by:

getArgs in interface FunctionCall

Returns:

argument list

isEverything

public boolean isEverything(ExpressionVisitor visitor)

Description copied from class: Expression

Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.

Specified by:

isEverything in class Expression

Parameters:

visitor - the visitor

Returns:

if the criteria can be fulfilled

getCost

public int getCost()

Description copied from class: Expression

Estimate the cost to process the expression. Used when optimizing the query, to calculate the query plan with the lowest estimated cost.

Specified by:

getCost in class Expression

Returns:

the estimated cost

isDeterministic

public boolean isDeterministic()

Description copied from interface: FunctionCall

Whether the function always returns the same result for the same parameters.

Specified by:

isDeterministic in interface FunctionCall

Returns:

true if it does