org.hibernate.hql.internal.ast.tree.QueryNode Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
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*
*/
package org.hibernate.hql.internal.ast.tree;
import org.hibernate.hql.internal.antlr.HqlSqlTokenTypes;
import org.hibernate.hql.internal.antlr.SqlTokenTypes;
import org.hibernate.hql.internal.ast.util.ASTUtil;
import org.hibernate.hql.internal.ast.util.ColumnHelper;
import org.hibernate.internal.CoreLogging;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.type.Type;
import antlr.SemanticException;
import antlr.collections.AST;
/**
* Defines a top-level AST node representing an HQL select statement.
*
* @author Joshua Davis
*/
public class QueryNode extends AbstractRestrictableStatement implements SelectExpression {
private static final CoreMessageLogger LOG = CoreLogging.messageLogger( QueryNode.class );
private OrderByClause orderByClause;
private int scalarColumnIndex = -1;
@Override
public int getStatementType() {
return HqlSqlTokenTypes.QUERY;
}
@Override
public boolean needsExecutor() {
return false;
}
@Override
protected int getWhereClauseParentTokenType() {
return SqlTokenTypes.FROM;
}
@Override
protected CoreMessageLogger getLog() {
return LOG;
}
/**
* Locate the select clause that is part of this select statement.
*
* Note, that this might return null as derived select clauses (i.e., no
* select clause at the HQL-level) get generated much later than when we
* get created; thus it depends upon lifecycle.
*
* @return Our select clause, or null.
*/
public final SelectClause getSelectClause() {
// Due to the complexity in initializing the SelectClause, do not generate one here.
// If it is not found; simply return null...
//
// Also, do not cache since it gets generated well after we are created.
return (SelectClause) ASTUtil.findTypeInChildren( this, SqlTokenTypes.SELECT_CLAUSE );
}
public final boolean hasOrderByClause() {
OrderByClause orderByClause = locateOrderByClause();
return orderByClause != null && orderByClause.getNumberOfChildren() > 0;
}
public final OrderByClause getOrderByClause() {
if ( orderByClause == null ) {
orderByClause = locateOrderByClause();
// if there is no order by, make one
if ( orderByClause == null ) {
LOG.debug( "getOrderByClause() : Creating a new ORDER BY clause" );
orderByClause = (OrderByClause) getWalker().getASTFactory().create( SqlTokenTypes.ORDER, "ORDER" );
// Find the WHERE; if there is no WHERE, find the FROM...
AST prevSibling = ASTUtil.findTypeInChildren( this, SqlTokenTypes.WHERE );
if ( prevSibling == null ) {
prevSibling = ASTUtil.findTypeInChildren( this, SqlTokenTypes.FROM );
}
// Now, inject the newly built ORDER BY into the tree
orderByClause.setNextSibling( prevSibling.getNextSibling() );
prevSibling.setNextSibling( orderByClause );
}
}
return orderByClause;
}
private OrderByClause locateOrderByClause() {
return (OrderByClause) ASTUtil.findTypeInChildren( this, SqlTokenTypes.ORDER );
}
private String alias;
@Override
public String getAlias() {
return alias;
}
@Override
public FromElement getFromElement() {
return null;
}
@Override
public boolean isConstructor() {
return false;
}
@Override
public boolean isReturnableEntity() throws SemanticException {
return false;
}
@Override
public boolean isScalar() throws SemanticException {
return true;
}
@Override
public void setAlias(String alias) {
this.alias = alias;
}
@Override
public void setScalarColumn(int i) throws SemanticException {
scalarColumnIndex = i;
setScalarColumnText( i );
}
@Override
public int getScalarColumnIndex() {
return scalarColumnIndex;
}
@Override
public void setScalarColumnText(int i) throws SemanticException {
ColumnHelper.generateSingleScalarColumn( this, i );
}
@Override
public Type getDataType() {
return ( (SelectExpression) getSelectClause().getFirstSelectExpression() ).getDataType();
}
}