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

Class SelectExpression

java.lang.Object

com.aquima.interactions.expressions.optimizer.nodes.SelectExpression

All Implemented Interfaces:

IExpressionNode, Serializable

public class SelectExpression
extends Object
implements IExpressionNode

The select expression can be used to retrieve one or more values that match the specified condition.

Since:

6.4

Author:

O. Kerpershoek

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
SelectExpression(Type resultType, IExpressionNode whatExpr, Identifier alias, IExpressionNode fromExpr, IExpressionNode whereExpr)	Constructs the select expression.

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.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

SelectExpression

public SelectExpression(Type resultType,
 IExpressionNode whatExpr,
 Identifier alias,
 IExpressionNode fromExpr,
 IExpressionNode whereExpr)

Constructs the select expression.

Parameters:

resultType - The type of the result (mandatory)

whatExpr - The expression that should be used to select the value(s) from the "from expression" (mandatory).

alias - The alias that is used for each item present in the result of the from expression (mandatory).

fromExpr - The expression that should be used to select the list of values the what expression should operate on (mandatory).

whereExpr - The condition that should be applied to each value in the result of the from expression (optional).

Method Details

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