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

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.AbstractSingleEncapsulatedExpressionStateObject
              org.eclipse.persistence.jpa.jpql.model.query.AggregateFunctionStateObject

All Implemented Interfaces:

StateObject

Direct Known Subclasses:

AvgFunctionStateObject, CountFunctionStateObject, MaxFunctionStateObject, MinFunctionStateObject, SumFunctionStateObject

public abstract class AggregateFunctionStateObject
extends AbstractSingleEncapsulatedExpressionStateObject

In the SELECT clause the result of a query may be the result of an aggregate function applied to a path expression.

BNF: aggregate_expression ::= {AVG|MAX|MIN|SUM}([DISTINCT] state_field_path_expression) |
                              COUNT([DISTINCT] identification_variable | state_field_path_expression | single_valued_association_path_expression)

Version:

2.4

See Also:

AggregateFunction

Author:

Pascal Filion

Since:

2.4

Field Summary

static java.lang.String

DISTINCT_PROPERTY Notifies the visibility of the DISTINCT identifier has changed.

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

STATE_OBJECT_PROPERTY

Constructor Summary

protected	AggregateFunctionStateObject(StateObject parent) Creates a new AggregateFunctionStateObject.
protected	AggregateFunctionStateObject(StateObject parent, boolean distinct, StateObject stateObject) Creates a new AggregateStateObject.
protected	AggregateFunctionStateObject(StateObject parent, boolean distinct, java.lang.String path) Creates a new AggregateFunctionStateObject.
protected	AggregateFunctionStateObject(StateObject parent, StateObject stateObject) Creates a new AggregateStateObject.
protected	AggregateFunctionStateObject(StateObject parent, java.lang.String path) Creates a new AggregateFunctionStateObject.

Method Summary

AggregateFunction	getExpression() Returns the actual parsed object if this StateObject representation of the JPQL query was created by parsing an existing JPQL query.
boolean	hasDistinct() Sets whether the DISTINCT keyword should be part of the query, which is used to return only distinct (different) values.
boolean	isEquivalent(StateObject stateObject) Determines whether the given StateObject is equivalent to this one, i.e. the information of both StateObject is the same.
void	setDistinct(boolean distinct) Sets whether the DISTINCT keyword should be part of the query, which is used to return only distinct (different) values
void	setStateObject(StateObject stateObject) Sets the given StateObject to represent the new encapsulated expression.
void	toggleDistinct() Reverses the visibility of the DISTINCT identifier.
protected void	toTextEncapsulatedExpression(java.lang.Appendable writer) Prints out a string representation of this encapsulated information, which should not be used to define a true string representation of a JPQL query but should be used for debugging purposes.

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

addChildren, getQueryBNFId, getStateObject, hasStateObject, parse

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

getIdentifier, 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

Methods inherited from interface org.eclipse.persistence.jpa.jpql.model.query.StateObject

accept

Field Detail

DISTINCT_PROPERTY

public static final java.lang.String DISTINCT_PROPERTY

Notifies the visibility of the DISTINCT identifier has changed.

See Also:

Constant Field Values

Constructor Detail

AggregateFunctionStateObject

protected AggregateFunctionStateObject(StateObject parent)

Creates a new AggregateFunctionStateObject.

Parameters:

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

Throws:

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

AggregateFunctionStateObject

protected AggregateFunctionStateObject(StateObject parent,
                                       boolean distinct,
                                       StateObject stateObject)

Creates a new AggregateStateObject.

Parameters:

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

distinct - true to add DISTINCT to the query in order to have distinct values; false if it is not required

stateObject - The StateObject representing the encapsulated expression

Throws:

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

AggregateFunctionStateObject

protected AggregateFunctionStateObject(StateObject parent,
                                       boolean distinct,
                                       java.lang.String path)

Creates a new AggregateFunctionStateObject.

Parameters:

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

distinct - true to add DISTINCT to the query in order to have distinct values; false if it is not required

path - Either the identification variable or the state field path expression

Throws:

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

AggregateFunctionStateObject

protected AggregateFunctionStateObject(StateObject parent,
                                       StateObject stateObject)

Creates a new AggregateStateObject.

Parameters:

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

stateObject - The StateObject representing the encapsulated expression

Throws:

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

AggregateFunctionStateObject

protected AggregateFunctionStateObject(StateObject parent,
                                       java.lang.String path)

Creates a new AggregateFunctionStateObject.

Parameters:

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

path - Either the identification variable or the state field path expression

Throws:

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

Method Detail

getExpression

public AggregateFunction 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 AbstractSingleEncapsulatedExpressionStateObject

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)

hasDistinct

public boolean hasDistinct()

Sets whether the DISTINCT keyword should be part of the query, which is used to return only distinct (different) values.

Returns:

true to add DISTINCT to the query in order to have distinct values; false if it is not required

isEquivalent

public boolean isEquivalent(StateObject stateObject)

Determines whether the given StateObject is equivalent to this one, i.e. the information of both StateObject is the same.

Specified by:

isEquivalent in interface StateObject

Overrides:

isEquivalent in class AbstractSingleEncapsulatedExpressionStateObject

Parameters:

stateObject - The StateObject to compare its content to this one

Returns:

true if both object are equivalent; false otherwise

setDistinct

public void setDistinct(boolean distinct)

Sets whether the DISTINCT keyword should be part of the query, which is used to return only distinct (different) values

Parameters:

distinct - true to add DISTINCT to the query in order to have distinct values; false if it is not required

setStateObject

public void setStateObject(StateObject stateObject)

Sets the given StateObject to represent the new encapsulated expression.

Overrides:

setStateObject in class AbstractSingleEncapsulatedExpressionStateObject

Parameters:

stateObject - The new encapsulated StateObject

toggleDistinct

public void toggleDistinct()

Reverses the visibility of the DISTINCT identifier.

toTextEncapsulatedExpression

protected void toTextEncapsulatedExpression(java.lang.Appendable writer)
                                     throws java.io.IOException

Prints out a string representation of this encapsulated information, which should not be used to define a true string representation of a JPQL query but should be used for debugging purposes.

Overrides:

toTextEncapsulatedExpression in class AbstractSingleEncapsulatedExpressionStateObject

Parameters:

writer - The writer used to print out the string representation of the encapsulated information

Throws:

java.io.IOException - This should never happens, only required because Appendable is used instead of StringBuilder for instance