/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.hql.internal.ast.tree;
import antlr.collections.AST;

Type definition for Statements which are restrictable via a where-clause (and
thus also having a from-clause).
Author:
Steve Ebersole/**
 * Type definition for Statements which are restrictable via a where-clause (and
 * thus also having a from-clause).
 *
 * @author Steve Ebersole
 */
public interface RestrictableStatement extends Statement {
	
Retrieve the from-clause in effect for this statement.
Returns:
The from-clause for this statement; could be null if the from-clause
has not yet been parsed/generated./**
	 * Retrieve the from-clause in effect for this statement.
	 *
	 * @return The from-clause for this statement; could be null if the from-clause
	 * has not yet been parsed/generated.
	 */
	public FromClause getFromClause();

	
Does this statement tree currently contain a where clause?
Returns:
True if a where-clause is found in the statement tree and
that where clause actually defines restrictions; false otherwise./**
	 * Does this statement tree currently contain a where clause?
	 *
	 * @return True if a where-clause is found in the statement tree and
	 * that where clause actually defines restrictions; false otherwise.
	 */
	public boolean hasWhereClause();

	
Retrieve the where-clause defining the restriction(s) in effect for
this statement.

Note that this will generate a where-clause if one was not found, so caution
needs to taken prior to calling this that restrictions will actually exist
in the resulting statement tree (otherwise "unexpected end of subtree" errors
might occur during rendering).
Returns:
The where clause./**
	 * Retrieve the where-clause defining the restriction(s) in effect for
	 * this statement.
	 * <p/>
	 * Note that this will generate a where-clause if one was not found, so caution
	 * needs to taken prior to calling this that restrictions will actually exist
	 * in the resulting statement tree (otherwise "unexpected end of subtree" errors
	 * might occur during rendering).
	 *
	 * @return The where clause.
	 */
	public AST getWhereClause();
}