Class ConditionalExpression

java.lang.Object

ConditionalExpression

Direct Known Subclasses:

Comparison, NotExpression, OrExpression, TrueExpression

public abstract class ConditionalExpression
extends Object

An abstract class that represents a conditional expression like those found in the WHERE clause of a SQL statement.

Constructor Summary

Constructors

Constructor and Description
ConditionalExpression() Default constructor used when constructing an object of a subclass that has no subexpressions (e.g., a TrueExpression) or that has subexpressions that are not ConditionalExpressions (e.g., a Comparison).
ConditionalExpression(ConditionalExpression left, ConditionalExpression right) Constructor used when constructing an object of a subclass that has one or two subexpressions.

Method Summary

Modifier and Type	Method and Description
ConditionalExpression	getLeft() Returns the left (i.e., the first) subexpression of the expression represented by the called object.
ConditionalExpression	getRight() Returns the right (i.e., the second) subexpression of the expression represented by the called object.
abstract boolean	isTrue() Evaluates the expression represented by the called object, based on the current truth values of the subexpressions.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConditionalExpression

public ConditionalExpression()

Default constructor used when constructing an object of a subclass that has no subexpressions (e.g., a TrueExpression) or that has subexpressions that are not ConditionalExpressions (e.g., a Comparison).

ConditionalExpression

public ConditionalExpression(ConditionalExpression left,
                             ConditionalExpression right)

Constructor used when constructing an object of a subclass that has one or two subexpressions.

Parameters:

left - one of the conditional subexpressions

right - the other conditional subexpression

Method Detail

getLeft

public ConditionalExpression getLeft()

Returns the left (i.e., the first) subexpression of the expression represented by the called object.

Returns:

the left subexpression

getRight

public ConditionalExpression getRight()

Returns the right (i.e., the second) subexpression of the expression represented by the called object.

Returns:

the right subexpression

isTrue

public abstract boolean isTrue()

Evaluates the expression represented by the called object, based on the current truth values of the subexpressions.

Returns:

true if the expression is true, and false if it is false!