com.espertech.esper.client.soda
Class CountProjectionExpression

java.lang.Object
  com.espertech.esper.client.soda.ExpressionBase
      com.espertech.esper.client.soda.CountProjectionExpression

All Implemented Interfaces:

Expression, java.io.Serializable

public class CountProjectionExpression
extends ExpressionBase

Count of the (distinct) values returned by an expression, equivalent to "count(distinct property)"

See Also:

Serialized Form

Constructor Summary

CountProjectionExpression()
Ctor.

CountProjectionExpression(boolean isDistinct)
Ctor - for use to create an expression tree, without inner expression

CountProjectionExpression(Expression expression, boolean isDistinct)
Ctor - adds the expression to project.

Method Summary

boolean	getDistinct() Returns true if the projection considers distinct values only.
ExpressionPrecedenceEnum	getPrecedence() Returns precedence.
boolean	isDistinct() Returns true if the projection considers distinct values only.
void	setDistinct(boolean distinct) Set the distinct flag indicating the projection considers distinct values only.
void	toPrecedenceFreeEPL(java.io.StringWriter writer) Renders the expressions and all it's child expression, in full tree depth, as a string in language syntax.

Methods inherited from class com.espertech.esper.client.soda.ExpressionBase

addChild, getChildren, getTreeObjectName, renderAggregation, setChildren, setTreeObjectName, toEPL, toPrecedenceFreeEPL, toPrecedenceFreeEPL

Methods inherited from class java.lang.Object

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

Constructor Detail

CountProjectionExpression

public CountProjectionExpression()

Ctor.

CountProjectionExpression

public CountProjectionExpression(boolean isDistinct)

Ctor - for use to create an expression tree, without inner expression

Parameters:

isDistinct - true if distinct

CountProjectionExpression

public CountProjectionExpression(Expression expression,
                                 boolean isDistinct)

Ctor - adds the expression to project.

Parameters:

expression - returning values to project

isDistinct - true if distinct

Method Detail

getPrecedence

public ExpressionPrecedenceEnum getPrecedence()

Description copied from interface: Expression

Returns precedence.

Returns:

precedence

toPrecedenceFreeEPL

public void toPrecedenceFreeEPL(java.io.StringWriter writer)

Description copied from class: ExpressionBase

Renders the expressions and all it's child expression, in full tree depth, as a string in language syntax.

Specified by:

toPrecedenceFreeEPL in class ExpressionBase

Parameters:

writer - is the output to use

isDistinct

public boolean isDistinct()

Returns true if the projection considers distinct values only.

Returns:

true if distinct

getDistinct

public boolean getDistinct()

Returns true if the projection considers distinct values only.

Returns:

true if distinct

setDistinct

public void setDistinct(boolean distinct)

Set the distinct flag indicating the projection considers distinct values only.

Parameters:

distinct - true for distinct, false for not distinct