// $Id: IndexNode.java 7460 2005-07-12 20:27:29Z steveebersole $
package org.hibernate.hql.ast.tree;
import org.hibernate.QueryException;
import org.hibernate.engine.JoinSequence;
import org.hibernate.hql.ast.SqlGenerator;
import org.hibernate.hql.ast.util.SessionFactoryHelper;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.type.CollectionType;
import org.hibernate.type.Type;
import antlr.RecognitionException;
import antlr.SemanticException;
import antlr.collections.AST;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Represents the [] operator and provides it's semantics.
*
* @author josh Aug 14, 2004 7:07:10 AM
*/
public class IndexNode extends FromReferenceNode {
private static final Log log = LogFactory.getLog( IndexNode.class );
public void setScalarColumnText(int i) throws SemanticException {
throw new UnsupportedOperationException( "An IndexNode cannot generate column text!" );
}
public void prepareForDot(String propertyName) throws SemanticException {
FromElement fromElement = getFromElement();
if ( fromElement == null ) {
throw new IllegalStateException( "No FROM element for index operator!" );
}
QueryableCollection queryableCollection = fromElement.getQueryableCollection();
if ( queryableCollection != null && !queryableCollection.isOneToMany() ) {
FromReferenceNode collectionNode = ( FromReferenceNode ) getFirstChild();
String path = collectionNode.getPath() + "[]." + propertyName;
if ( log.isDebugEnabled() ) {
log.debug( "Creating join for many-to-many elements for " + path );
}
FromElementFactory factory = new FromElementFactory( fromElement.getFromClause(), fromElement, path );
// This will add the new from element to the origin.
FromElement elementJoin = factory.createElementJoin( queryableCollection );
setFromElement( elementJoin );
}
}
public void resolveIndex(AST parent) throws SemanticException {
throw new UnsupportedOperationException();
}
public void resolve(boolean generateJoin, boolean implicitJoin, String classAlias, AST parent)
throws SemanticException {
if ( isResolved() ) {
return;
}
FromReferenceNode collectionNode = ( FromReferenceNode ) getFirstChild();
SessionFactoryHelper sessionFactoryHelper = getSessionFactoryHelper();
collectionNode.resolveIndex( this ); // Fully resolve the map reference, create implicit joins.
Type type = collectionNode.getDataType();
if ( !type.isCollectionType() ) {
throw new SemanticException( "The [] operator cannot be applied to type " + type.toString() );
}
String collectionRole = ( ( CollectionType ) type ).getRole();
QueryableCollection queryableCollection = sessionFactoryHelper.requireQueryableCollection( collectionRole );
if ( !queryableCollection.hasIndex() ) {
throw new QueryException( "unindexed fromElement before []: " + collectionNode.getPath() );
}
// Generate the inner join -- The elements need to be joined to the collection they are in.
FromElement fromElement = collectionNode.getFromElement();
String elementTable = fromElement.getTableAlias();
FromClause fromClause = fromElement.getFromClause();
String path = collectionNode.getPath();
FromElement elem = fromClause.findCollectionJoin( path );
if ( elem == null ) {
FromElementFactory factory = new FromElementFactory( fromClause, fromElement, path );
elem = factory.createCollectionElementsJoin( queryableCollection, elementTable );
if ( log.isDebugEnabled() ) {
log.debug( "No FROM element found for the elements of collection join path " + path
+ ", created " + elem );
}
}
else {
if ( log.isDebugEnabled() ) {
log.debug( "FROM element found for collection join path " + path );
}
}
// Add the condition to the join sequence that qualifies the indexed element.
AST index = collectionNode.getNextSibling(); // The index should be a constant, which will have been processed already.
if ( index == null ) {
throw new QueryException( "No index value!" );
}
setFromElement( fromElement ); // The 'from element' that represents the elements of the collection.
// Sometimes use the element table alias, sometimes use the... umm... collection table alias (many to many)
String collectionTableAlias = elementTable;
if ( elem.getCollectionTableAlias() != null ) {
collectionTableAlias = elem.getCollectionTableAlias();
}
// TODO: get SQL rendering out of here, create an AST for the join expressions.
// Use the SQL generator grammar to generate the SQL text for the index expression.
JoinSequence joinSequence = fromElement.getJoinSequence();
String[] indexCols = queryableCollection.getIndexColumnNames();
if ( indexCols.length != 1 ) {
throw new QueryException( "composite-index appears in []: " + collectionNode.getPath() );
}
SqlGenerator gen = new SqlGenerator( getSessionFactoryHelper().getFactory() );
try {
gen.simpleExpr( index ); //TODO: used to be exprNoParens! was this needed?
}
catch ( RecognitionException e ) {
throw new QueryException( e.getMessage(), e );
}
String expression = gen.getSQL();
joinSequence.addCondition( collectionTableAlias + '.' + indexCols[0] + " = " + expression );
// Now, set the text for this node. It should be the element columns.
String[] elementColumns = queryableCollection.getElementColumnNames( elementTable );
setText( elementColumns[0] );
setResolved();
}
}
|