org.gvsig.expressionevaluator.impl.function.aggregate

Class CountFunction

java.lang.Object

org.gvsig.expressionevaluator.spi.AbstractFunction

org.gvsig.expressionevaluator.impl.function.aggregate.CountFunction

All Implemented Interfaces:

Function

public class CountFunction
extends AbstractFunction

Field Summary

Fields inherited from class org.gvsig.expressionevaluator.spi.AbstractFunction

LOGGER, TYPE_BIGDECIMAL, TYPE_BOOLEAN, TYPE_DATE, TYPE_DOUBLE, TYPE_FLOAT, TYPE_INT, TYPE_LONG, TYPE_NULL, TYPE_STRING

Fields inherited from interface org.gvsig.expressionevaluator.Function

GROUP_AGGREGATE, GROUP_BOOLEAN, GROUP_CONVERSION, GROUP_DATETIME, GROUP_NUMERIC, GROUP_OGC, GROUP_OTHER, GROUP_PROGRAMMING, GROUP_STRING

Constructor Summary

Constructors

Constructor and Description
CountFunction()

Method Summary

Modifier and Type	Method and Description
boolean	allowConstantFolding() Returns true if the function always returns the same value for the same parameters.
java.lang.Object	call(Interpreter interpreter, java.lang.Object[] args)

Methods inherited from class org.gvsig.expressionevaluator.spi.AbstractFunction

addAlias, aliases, argc, call, checkDoubleValue, checkFloatValue, description, descriptionArgs, getBigDecimal, getBoolean, getBoolean, getBoolean, getBoolean, getBoolean, getComparable, getComparable, getDate, getDate, getDouble, getDouble, getFile, getFile, getFloat, getFloat, getFullDescription, getInt, getInt, getInt, getJsonArray, getJsonArray, getJsonObject, getJsonObject, getJsonStructure, getJsonStructure, getList, getLocalDateTime, getLocalDateTime, getLong, getLong, getObject, getObject, getStr, getStr, getType, getURL, group, isHidden, isNull, isOperator, isSQLCompatible, name, returnType, template, toBoolean, toString, toString, toValue, useArgumentsInsteadObjects

Methods inherited from class java.lang.Object

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

Constructor Detail

CountFunction

public CountFunction()

Method Detail

allowConstantFolding

public boolean allowConstantFolding()

Description copied from interface: Function

Returns true if the function always returns the same value for the same parameters. If so, it is possible to optimize the generated code through the process of "constant folding". https://en.wikipedia.org/wiki/Constant_folding

Specified by:

allowConstantFolding in interface Function

Overrides:

allowConstantFolding in class AbstractFunction

Returns:

true if this function allow constant folding optimization.

call

public java.lang.Object call(Interpreter interpreter,
                             java.lang.Object[] args)