Package com.aquima.interactions.expressions.optimizer.nodes

Class ExistsExpression

java.lang.Object

com.aquima.interactions.expressions.optimizer.nodes.ExistsExpression

All Implemented Interfaces:

IExpressionNode, Serializable

public class ExistsExpression
extends Object
implements IExpressionNode

The exists expression can be used to check if at least one of the selected values matches the condition.

Since:

6.4

Author:

O. Kerpershoek

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
ExistsExpression(IExpressionNode fromExpr, Identifier alias, IExpressionNode whereExpr)	Constructs the exists expression with the required arguments.

Method Summary

Modifier and Type	Method	Description
IValue	evaluate(IValueEnvironment environment)	This method evaluates the node using the environment passed as argument and returns the result as a value or null if the result is unknown.
protected Identifier	getAlias()
protected IExpressionNode	getFromExpr()
protected IExpressionNode	getWhereExpr()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

ExistsExpression

public ExistsExpression(IExpressionNode fromExpr,
 Identifier alias,
 IExpressionNode whereExpr)

Constructs the exists expression with the required arguments.

Parameters:

fromExpr - The expression that should be used to retrieve the values.

alias - The alias that is used for the values.

whereExpr - The condition that should be evaluated for each value.

Method Details

getAlias

protected Identifier getAlias()

getFromExpr

protected IExpressionNode getFromExpr()

getWhereExpr

protected IExpressionNode getWhereExpr()

evaluate

public IValue evaluate(IValueEnvironment environment)

Description copied from interface: IExpressionNode

This method evaluates the node using the environment passed as argument and returns the result as a value or null if the result is unknown.

Specified by:

evaluate in interface IExpressionNode

Parameters:

environment - The environment that should be used when evaluating the node.

Returns:

The result of the evaluation, or null if the result is unknown.

toString

public String toString()

Overrides:

toString in class Object