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IndexNode.javaAPI DocHibernate 3.2.55498Tue Jul 12 15:27:30 BST 2005org.hibernate.hql.ast.tree

IndexNode

public class IndexNode extends FromReferenceNode
Represents the [] operator and provides it's semantics.
author
josh Aug 14, 2004 7:07:10 AM

Fields Summary
private static final Log
log
Constructors Summary
Methods Summary
public voidprepareForDot(java.lang.String propertyName)

		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 voidresolve(boolean generateJoin, boolean implicitJoin, java.lang.String classAlias, antlr.collections.AST parent)

		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();
	
public voidresolveIndex(antlr.collections.AST parent)

		throw new UnsupportedOperationException();
	
public voidsetScalarColumnText(int i)


	      
		throw new UnsupportedOperationException( "An IndexNode cannot generate column text!" );