/*******************************************************************************
* Copyright (c) 2011, 2015 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation
*
******************************************************************************/
package org.eclipse.persistence.jpa.jpql.tools.model.query;
import org.eclipse.persistence.jpa.jpql.parser.SimpleSelectStatement;
import org.eclipse.persistence.jpa.jpql.tools.model.ISimpleSelectExpressionStateObjectBuilder;
/**
* This state object represents a subquery, which has at least a <code><b>SELECT</b></code> clause
* and a <code><b>FROM</b></code> clause. The other clauses are optional.
* <p>
* <b>BNF:</b> <code>subquery ::= simple_select_clause subquery_from_clause [where_clause] [groupby_clause] [having_clause]</code><p>
*
* @see SimpleSelectStatement
*
* @version 2.4
* @since 2.4
* @author Pascal Filion
*/
public class SimpleSelectStatementStateObject extends AbstractSelectStatementStateObject {
/**
* Creates a new <code>SimpleSelectStatementStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public SimpleSelectStatementStateObject(StateObject parent) {
super(parent);
}
/**
* {@inheritDoc}
*/
public void accept(StateObjectVisitor visitor) {
visitor.visit(this);
}
/**
* Adds a new derived collection declaration to the <code><b>FROM</b></code> clause.
*
* @return The {@link CollectionMemberDeclarationStateObject} representing the collection
* declaration
*/
public CollectionMemberDeclarationStateObject addDerivedCollectionDeclaration() {
return getFromClause().addDerivedCollectionDeclaration();
}
/**
* Adds a new derived collection declaration to the <code><b>FROM</b></code> clause.
*
* @param collectionValuedPath The collection-valued path expression
* @return The {@link CollectionMemberDeclarationStateObject} representing the collection
* declaration
*/
public CollectionMemberDeclarationStateObject addDerivedCollectionDeclaration(String collectionValuedPath) {
return getFromClause().addDerivedCollectionDeclaration(collectionValuedPath);
}
/**
* Adds a new derived identification variable declaration to the <code><b>FROM</b></code> clause.
*
* @return The {@link DerivedPathIdentificationVariableDeclarationStateObject} representing the collection
* declaration
*/
public DerivedPathIdentificationVariableDeclarationStateObject addDerivedPathDeclaration() {
return getFromClause().addDerivedPathDeclaration();
}
/**
* Adds a new derived identification variable declaration to the <code><b>FROM</b></code> clause.
*
* @param path Either the derived singled-valued object field or the collection-valued path expression
* @param identificationVariable The identification variable defining the given path
* @return The {@link DerivedPathIdentificationVariableDeclarationStateObject} representing the
* path declaration
*/
public DerivedPathIdentificationVariableDeclarationStateObject addDerivedPathDeclaration(String path,
String identificationVariable) {
return getFromClause().addDerivedPathDeclaration(path, identificationVariable);
}
/**
* {@inheritDoc}
*/
@Override
protected AbstractFromClauseStateObject buildFromClause() {
return new SimpleFromClauseStateObject(this);
}
/**
* {@inheritDoc}
*/
@Override
protected AbstractSelectClauseStateObject buildSelectClause() {
return new SimpleSelectClauseStateObject(this);
}
/**
* {@inheritDoc}
*/
@Override
public SimpleSelectStatement getExpression() {
return (SimpleSelectStatement) super.getExpression();
}
/**
* {@inheritDoc}
*/
@Override
public SimpleFromClauseStateObject getFromClause() {
return (SimpleFromClauseStateObject) super.getFromClause();
}
/**
* Creates and returns a new {@link ISimpleSelectExpressionStateObjectBuilder} that can be used
* to programmatically create a single select expression and once the expression is complete,
* {@link ISimpleSelectExpressionStateObjectBuilder#commit()} will push the {@link StateObject}
* representation of that expression as this clause's select expression.
*
* @return A new builder that can be used to quickly create a select expression
*/
public ISimpleSelectExpressionStateObjectBuilder getSelectBuilder() {
return getSelectClause().getBuilder();
}
/**
* {@inheritDoc}
*/
@Override
public SimpleSelectClauseStateObject getSelectClause() {
return (SimpleSelectClauseStateObject) super.getSelectClause();
}
/**
* Keeps a reference of the {@link SimpleSelectStatement parsed object} object, which should only
* be done when this object is instantiated during the conversion of a parsed JPQL query into
* {@link StateObject StateObjects}.
*
* @param expression The {@link SimpleSelectStatement parsed object} representing a subquery
* <code><b>SELECT</b></code> statement
*/
public void setExpression(SimpleSelectStatement expression) {
super.setExpression(expression);
}
/**
* Sets the given {@link StateObject} as the <code><b>SELECT</b></code> clause's select item.
*
* @param stateObject The {@link StateObject} representing the single select item
*/
public void setSelectItem(StateObject stateObject) {
getSelectClause().setSelectItem(stateObject);
}
/**
* 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.
*
* @param jpqlFragment The portion of the query representing one or several select items
*/
public void setSelectItem(String jpqlFragment) {
getSelectClause().parse(jpqlFragment);
}
}