EclipseLink 2.4.2, build 'v20130514-5956486' API Reference

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

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

EclipseLink 2.4.2, build 'v20130514-5956486' API Reference