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

java.lang.Object
  org.eclipse.persistence.jpa.jpql.model.query.AbstractStateObject
      org.eclipse.persistence.jpa.jpql.model.query.AbstractListHolderStateObject<VariableDeclarationStateObject>
          org.eclipse.persistence.jpa.jpql.model.query.AbstractFromClauseStateObject
              org.eclipse.persistence.jpa.jpql.model.query.SimpleFromClauseStateObject

All Implemented Interfaces:

DeclarationStateObject, ListHolderStateObject<VariableDeclarationStateObject>, StateObject

public class SimpleFromClauseStateObject
extends AbstractFromClauseStateObject

The FROM clause of a sub-query defines the domain of the sub-query by declaring identification variables. An identification variable is an identifier declared in the FROM clause of a sub-query. The domain of the sub-query may be constrained by path expressions. Identification variables designate instances of a particular entity abstract schema type. The FROM clause can contain multiple identification variable declarations separated by a comma (,).

BNF: subquery_from_clause ::= FROM subselect_identification_variable_declaration {, subselect_identification_variable_declaration}*

Version:

2.4

See Also:

SimpleFromClause

Author:

Pascal Filion

Since:

2.4

Field Summary

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

VARIABLE_DECLARATIONS_LIST

Constructor Summary

SimpleFromClauseStateObject(SimpleSelectStatementStateObject parent)
Creates a new SimpleFromClauseStateObject.

Method Summary

void	accept(StateObjectVisitor visitor) Visits this StateObject by the given visitor.
CollectionMemberDeclarationStateObject	addDerivedCollectionDeclaration() Adds a new derived collection declaration to the FROM clause.
CollectionMemberDeclarationStateObject	addDerivedCollectionDeclaration(java.lang.String collectionValuedPath) Adds a new derived collection declaration to the FROM clause.
DerivedPathIdentificationVariableDeclarationStateObject	addDerivedPathDeclaration() Adds a new derived identification variable declaration to the FROM clause.
DerivedPathIdentificationVariableDeclarationStateObject	addDerivedPathDeclaration(java.lang.String path, java.lang.String identificationVariable) Adds a new derived identification variable declaration to the FROM clause.
java.lang.String	declarationBNF() Returns the BNF of the declaration part of this clause.
IManagedType	findManagedType(StateObject stateObject) Returns the IManagedType for the given identification variable.
SimpleFromClause	getExpression() Returns the actual parsed object if this StateObject representation of the JPQL query was created by parsing an existing JPQL query.
SimpleSelectStatementStateObject	getParent() Returns the parent of this StateObject.
void	setExpression(SimpleFromClause 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.AbstractFromClauseStateObject

addCollectionDeclaration, addCollectionDeclaration, addProblems, addRangeDeclaration, addRangeDeclaration, addRangeDeclaration, declarations, findIdentificationVariable, getDeclaration, getManagedType, identificationVariables, isEquivalent, listName, parse, toTextInternal

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

addChildren, addItem, addItems, addListChangeListener, areChildrenEquivalent, canMoveDown, canMoveUp, getItem, hasItems, initialize, items, itemsSize, moveDown, moveUp, removeItem, removeItems, removeListChangeListener, toStringItems

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

acceptUnknownVisitor, acceptUnknownVisitor, addPropertyChangeListener, areEquivalent, buildProblem, buildProblem, buildStateObject, buildStateObjects, checkParent, children, decorate, equals, firePropertyChanged, getChangeSupport, getDecorator, getGrammar, getManagedTypeProvider, getQueryBuilder, getRoot, getType, getType, getTypeHelper, getTypeRepository, hashCode, 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

addPropertyChangeListener, children, decorate, getDecorator, getGrammar, getManagedTypeProvider, getQueryBuilder, getRoot, isDecorated, removePropertyChangeListener, setParent, toString, toText

Constructor Detail

SimpleFromClauseStateObject

public SimpleFromClauseStateObject(SimpleSelectStatementStateObject parent)

Creates a new SimpleFromClauseStateObject.

Parameters:

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

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

addDerivedCollectionDeclaration

public CollectionMemberDeclarationStateObject addDerivedCollectionDeclaration()

Adds a new derived collection declaration to the FROM clause.

Returns:

The CollectionMemberDeclarationStateObject representing the collection declaration

addDerivedCollectionDeclaration

public CollectionMemberDeclarationStateObject addDerivedCollectionDeclaration(java.lang.String collectionValuedPath)

Adds a new derived collection declaration to the FROM clause.

Parameters:

collectionValuedPath - The collection-valued path expression

Returns:

The CollectionMemberDeclarationStateObject representing the collection declaration

addDerivedPathDeclaration

public DerivedPathIdentificationVariableDeclarationStateObject addDerivedPathDeclaration()

Adds a new derived identification variable declaration to the FROM clause.

Returns:

The DerivedPathIdentificationVariableDeclarationStateObject representing the path declaration

addDerivedPathDeclaration

public DerivedPathIdentificationVariableDeclarationStateObject addDerivedPathDeclaration(java.lang.String path,
                                                                                         java.lang.String identificationVariable)

Adds a new derived identification variable declaration to the FROM clause.

Parameters:

path - Either the derived singled-valued object field or the collection-valued path expression

identificationVariable - The identification variable defining the given path

Returns:

The DerivedPathIdentificationVariableDeclarationStateObject representing the path declaration

declarationBNF

public java.lang.String declarationBNF()

Returns the BNF of the declaration part of this clause.

Specified by:

declarationBNF in class AbstractFromClauseStateObject

Returns:

The BNF of the declaration part of this clause

findManagedType

public IManagedType findManagedType(StateObject stateObject)

Returns the IManagedType for the given identification variable. If the declaration is for a subquery and there is no managed type associated with the identification then the search will traverse up the query hierarchy.

SELECT e FROM Department d JOIN KEY(d.employees).addresses a

In the above query, the managed type associated with the identification variable:

• d is "Department"
• a is "Address"

Parameters:

stateObject - The StateObject that should be an simple identification variable or an encapsulated identification variable with the identifier KEY or VALUE

Returns:

The IManagedType representing the domain object declared by the given identification variable

See Also:

DeclarationStateObject.getManagedType(StateObject)

getExpression

public SimpleFromClause 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 AbstractFromClauseStateObject

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)

getParent

public SimpleSelectStatementStateObject getParent()

Returns the parent of this StateObject.

Specified by:

getParent in interface StateObject

Overrides:

getParent in class AbstractFromClauseStateObject

Returns:

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

setExpression

public void setExpression(SimpleFromClause 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 subquery FROM