org.eclipse.persistence.jpa.jpql.model.query
Class NullIfExpressionStateObject

java.lang.Object
  org.eclipse.persistence.jpa.jpql.model.query.AbstractStateObject
      org.eclipse.persistence.jpa.jpql.model.query.AbstractEncapsulatedExpressionStateObject
          org.eclipse.persistence.jpa.jpql.model.query.AbstractDoubleEncapsulatedExpressionStateObject
              org.eclipse.persistence.jpa.jpql.model.query.NullIfExpressionStateObject

All Implemented Interfaces:

StateObject

public class NullIfExpressionStateObject
extends AbstractDoubleEncapsulatedExpressionStateObject

NULLIF returns the first expression if the two expressions are not equal. If the expressions are equal, NULLIF returns a null value of the type of the first expression.

NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL.

Returns the same type as the first expression.

BNF: nullif_expression::= NULLIF(scalar_expression, scalar_expression)

Version:

2.4

See Also:

NullIfExpression

Author:

Pascal Filion

Since:

2.4

Field Summary

Fields inherited from class org.eclipse.persistence.jpa.jpql.model.query.AbstractDoubleEncapsulatedExpressionStateObject

FIRST_STATE_OBJECT_PROPERTY, SECOND_STATE_OBJECT_PROPERTY

Constructor Summary

NullIfExpressionStateObject(StateObject parent)
Creates a new NullIfExpressionStateObject.

NullIfExpressionStateObject(StateObject parent, StateObject firstStateObject, StateObject secondStateObject)
Creates a new NullIfExpressionStateObject.

NullIfExpressionStateObject(StateObject parent, java.lang.String firstJpqlFragment, java.lang.String secondJpqlFragment)
Creates a new NullIfExpressionStateObject.

Method Summary

void	accept(StateObjectVisitor visitor) Visits this StateObject by the given visitor.
NullIfExpression	getExpression() Returns the actual parsed object if this StateObject representation of the JPQL query was created by parsing an existing JPQL query.
protected java.lang.String	getFirstQueryBNFId() Returns the unique identifier of the BNF that will be used to parse a JPQL fragment as the first encapsulated expression.
java.lang.String	getIdentifier() Returns the JPQL identifier of the expression represented by this AbstractSingleEncapsulatedExpressionStateObject.
protected java.lang.String	getSecondQueryBNFId() Returns the unique identifier of the BNF that will be used to parse a JPQL fragment as the second encapsulated expression.
void	setExpression(NullIfExpression expression) Keeps a reference of the parsed object object, which should only be done when this object is instantiated during the conversion of a parsed JPQL query into StateObjects.

Methods inherited from class org.eclipse.persistence.jpa.jpql.model.query.AbstractDoubleEncapsulatedExpressionStateObject

addChildren, getFirst, getSecond, hasFirst, hasSecond, isEquivalent, parseFirst, parseSecond, setFirst, setSecond, toTextEncapsulatedExpression

Methods inherited from class org.eclipse.persistence.jpa.jpql.model.query.AbstractEncapsulatedExpressionStateObject

toTextInternal

Methods inherited from class org.eclipse.persistence.jpa.jpql.model.query.AbstractStateObject

acceptUnknownVisitor, acceptUnknownVisitor, addProblems, addPropertyChangeListener, areEquivalent, buildProblem, buildProblem, buildStateObject, buildStateObjects, checkParent, children, decorate, equals, findIdentificationVariable, firePropertyChanged, getChangeSupport, getDeclaration, getDecorator, getGrammar, getManagedTypeProvider, getParent, getQueryBuilder, getRoot, getType, getType, getTypeHelper, getTypeRepository, hashCode, initialize, isDecorated, parent, parent, parent, removePropertyChangeListener, setExpression, setParent, toString, toString, toStringInternal, toStringItems, toText

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

NullIfExpressionStateObject

public NullIfExpressionStateObject(StateObject parent)

Creates a new NullIfExpressionStateObject.

Parameters:

parent - The parent of this state object, which cannot be null

Throws:

java.lang.NullPointerException - The given parent cannot be null

NullIfExpressionStateObject

public NullIfExpressionStateObject(StateObject parent,
                                   StateObject firstStateObject,
                                   StateObject secondStateObject)

Creates a new NullIfExpressionStateObject.

Parameters:

parent - The parent of this state object, which cannot be null

firstStateObject - The StateObject representing the first expression

secondStateObject - The StateObject representing the second expression

Throws:

java.lang.NullPointerException - The given parent cannot be null

NullIfExpressionStateObject

public NullIfExpressionStateObject(StateObject parent,
                                   java.lang.String firstJpqlFragment,
                                   java.lang.String secondJpqlFragment)

Creates a new NullIfExpressionStateObject.

Parameters:

parent - The parent of this state object, which cannot be null

firstJpqlFragment - The string representation of the first encapsulated expression to parse and to convert into a StateObject representation

secondJpqlFragment - The string representation of the second encapsulated expression to parse and to convert into a StateObject representation

Throws:

java.lang.NullPointerException - The given parent cannot be null

Method Detail

accept

public void accept(StateObjectVisitor visitor)

Visits this StateObject by the given visitor.

Parameters:

visitor - The visitor to visit this object

getExpression

public NullIfExpression getExpression()

Returns the actual parsed object if this StateObject representation of the JPQL query was created by parsing an existing JPQL query.

Specified by:

getExpression in interface StateObject

Overrides:

getExpression in class AbstractDoubleEncapsulatedExpressionStateObject

Returns:

The parsed object when a JPQL query is parsed and converted into a StateObject or null when the JPQL query is manually created (i.e. not from a string)

getFirstQueryBNFId

protected java.lang.String getFirstQueryBNFId()

Returns the unique identifier of the BNF that will be used to parse a JPQL fragment as the first encapsulated expression.

Specified by:

getFirstQueryBNFId in class AbstractDoubleEncapsulatedExpressionStateObject

Returns:

The query BNF ID for the first encapsulated expression

getIdentifier

public java.lang.String getIdentifier()

Returns the JPQL identifier of the expression represented by this AbstractSingleEncapsulatedExpressionStateObject.

Specified by:

getIdentifier in class AbstractEncapsulatedExpressionStateObject

Returns:

The JPQL identifier that is shown before the left parenthesis

getSecondQueryBNFId

protected java.lang.String getSecondQueryBNFId()

Returns the unique identifier of the BNF that will be used to parse a JPQL fragment as the second encapsulated expression.

Specified by:

getSecondQueryBNFId in class AbstractDoubleEncapsulatedExpressionStateObject

Returns:

The query BNF ID for the second encapsulated expression

setExpression

public void setExpression(NullIfExpression expression)

Keeps a reference of the parsed object object, which should only be done when this object is instantiated during the conversion of a parsed JPQL query into StateObjects.

Parameters:

expression - The parsed object representing a NULLIF expression