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

java.lang.Object
  org.eclipse.persistence.jpa.jpql.model.query.AbstractStateObject
      org.eclipse.persistence.jpa.jpql.model.query.AbstractSelectClauseStateObject

All Implemented Interfaces:

StateObject

Direct Known Subclasses:

SelectClauseStateObject, SimpleSelectClauseStateObject

public abstract class AbstractSelectClauseStateObject
extends AbstractStateObject

This state object represents the abstract definition of a SELECT clause, which is either the SELECT clause of the top-level query or of a subquery.

Version:

2.4

See Also:

AbstractSelectStatementStateObject, SelectClauseStateObject, SubQuerySelectClauseStateObject, AbstractSelectClause

Author:

Pascal Filion

Since:

2.4

Field Summary

static java.lang.String

DISTINCT_PROPERTY Notifies the distinct property has changed.

Constructor Summary

protected

AbstractSelectClauseStateObject(AbstractSelectStatementStateObject parent) Creates a new AbstractSelectClauseStateObject.

Method Summary

AbstractSelectClause	getExpression() Returns the actual parsed object if this StateObject representation of the JPQL query was created by parsing an existing JPQL query.
AbstractFromClauseStateObject	getFromClause() Returns the AbstractFromClauseStateObject representing the FROM clause.
AbstractSelectStatementStateObject	getParent() Returns the parent of this StateObject.
boolean	hasDistinct() Sets whether the DISTINCT keyword should be part of the query, which is used to return only distinct (different) values
abstract boolean	hasSelectItem() Determines whether this SELECT clause has a select item defined (only one can be set for a subquery's SELECT clause and many for a top-level query).
boolean	isEquivalent(StateObject stateObject) Determines whether the given StateObject is equivalent to this one, i.e. the information of both StateObject is the same.
abstract void	parse(java.lang.String jpqlFragment) Parses the given JPQL fragment and create the select item.
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	toggleDistinct() Changes the state of the DISTINCT identifier; either adds it if it's not present or removes it if it's present.

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

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

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 distinct property has changed.

See Also:

Constant Field Values

Constructor Detail

AbstractSelectClauseStateObject

protected AbstractSelectClauseStateObject(AbstractSelectStatementStateObject parent)

Creates a new AbstractSelectClauseStateObject.

Parameters:

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

Throws:

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

Method Detail

getExpression

public AbstractSelectClause 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 AbstractStateObject

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)

getFromClause

public AbstractFromClauseStateObject getFromClause()

Returns the AbstractFromClauseStateObject representing the FROM clause.

Returns:

The state object representing the FROM clause

getParent

public AbstractSelectStatementStateObject getParent()

Returns the parent of this StateObject.

Specified by:

getParent in interface StateObject

Overrides:

getParent in class AbstractStateObject

Returns:

Returns the parent of this StateObject, which is null only when this is the root of the hierarchy

hasDistinct

public boolean hasDistinct()

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

hasSelectItem

public abstract boolean hasSelectItem()

Determines whether this SELECT clause has a select item defined (only one can be set for a subquery's SELECT clause and many for a top-level query).

Returns:

true if this state object has children; false otherwise

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 AbstractStateObject

Parameters:

stateObject - The StateObject to compare its content to this one

Returns:

true if both object are equivalent; false otherwise

parse

public abstract void parse(java.lang.String jpqlFragment)

Parses the given JPQL fragment and create the select item. For the top-level query, the fragment can contain several select items but for a subquery, it can represent only one.

Parameters:

jpqlFragment - The portion of the query representing one or several select items

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

toggleDistinct

public void toggleDistinct()

Changes the state of the DISTINCT identifier; either adds it if it's not present or removes it if it's present.