org.eclipse.persistence.jpa.jpql
Class FromSubqueryResolver

java.lang.Object
  org.eclipse.persistence.jpa.jpql.Resolver
      org.eclipse.persistence.jpa.jpql.FromSubqueryResolver

public class FromSubqueryResolver
extends Resolver

This Resolver wraps a subquery that is used as the "root" object in a query's declaration.

Example:

 SELECT e.firstName
 FROM Employee e, (SELECT count(e2), e2.firstName FROM Employee e2) e3
 WHERE e.firstName = e3.firstName

Version:

2.4

Author:

Pascal Filion

Since:

2.4

Nested Class Summary

protected class	FromSubqueryResolver.VirtualManagedType This IManagedType represents a virtual managed type where its content will be derived from the subquery.
protected class	FromSubqueryResolver.VirtualMapping This virtual IMapping wraps one of the select items.
protected class	FromSubqueryResolver.VirtualMappingBuilder This visitor will traverse the SELECT clause and create virtual mappings for the state field path expressions and any expression aliased with a result variable.

Constructor Summary

FromSubqueryResolver(Resolver parent, JPQLQueryContext queryContext, SimpleSelectStatement subquery)
Creates a new FromSubqueryResolver.

Method Summary

void	accept(ResolverVisitor visitor) Visits this Resolver by the given visitor.
protected IType	buildType() Resolves the IType of the property handled by this Resolver.
protected ITypeDeclaration	buildTypeDeclaration() Resolves the ITypeDeclaration of the property handled by this Resolver.
IManagedType	getManagedType() Returns the IManagedType associated with the field handled by this Resolver.

Methods inherited from class org.eclipse.persistence.jpa.jpql.Resolver

addChild, checkParent, getChild, getMapping, getParent, getParentManagedType, getParentMapping, getParentType, getParentTypeDeclaration, getProvider, getQuery, getType, getType, getType, getTypeDeclaration, getTypeHelper, getTypeRepository, isNullAllowed, setNullAllowed

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FromSubqueryResolver

public FromSubqueryResolver(Resolver parent,
                            JPQLQueryContext queryContext,
                            SimpleSelectStatement subquery)

Creates a new FromSubqueryResolver.

Parameters:

parent - The parent of this resolver, which is never null

queryContext - The context used to query information about the application metadata and cached information

subquery -

Throws:

java.lang.NullPointerException - If the parent is null

Method Detail

accept

public void accept(ResolverVisitor visitor)

Visits this Resolver by the given visitor.

Specified by:

accept in class Resolver

Parameters:

visitor - The visitor to visit this object

buildType

protected IType buildType()

Resolves the IType of the property handled by this Resolver.

Overrides:

buildType in class Resolver

Returns:

Either the IType that was resolved by this Resolver or the IType for IType.UNRESOLVABLE_TYPE if it could not be resolved

buildTypeDeclaration

protected ITypeDeclaration buildTypeDeclaration()

Resolves the ITypeDeclaration of the property handled by this Resolver.

Specified by:

buildTypeDeclaration in class Resolver

Returns:

Either the ITypeDeclaration that was resolved by this Resolver or the ITypeDeclaration for IType.UNRESOLVABLE_TYPE if it could not be resolved

getManagedType

public IManagedType getManagedType()

Returns the IManagedType associated with the field handled by this Resolver. If this Resolver does not handle a field that has a IManagedType, then null should be returned.

For example: "SELECT e FROM Employee e", the Resolver for e would be returning the IManagedType for Employee.

Overrides:

getManagedType in class Resolver

Returns:

Either the IManagedType, if it could be resolved; null otherwise