// $Id: FromElementType.java 10825 2006-11-16 19:33:19Z steve.ebersole@jboss.com $
package org.hibernate.hql.ast.tree;
import java.util.Map;
import org.hibernate.MappingException;
import org.hibernate.QueryException;
import org.hibernate.util.ArrayHelper;
import org.hibernate.engine.JoinSequence;
import org.hibernate.hql.CollectionProperties;
import org.hibernate.hql.CollectionSubqueryFactory;
import org.hibernate.hql.NameGenerator;
import org.hibernate.hql.antlr.HqlSqlTokenTypes;
import org.hibernate.persister.collection.CollectionPropertyMapping;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.persister.entity.Joinable;
import org.hibernate.persister.entity.PropertyMapping;
import org.hibernate.persister.entity.Queryable;
import org.hibernate.type.EntityType;
import org.hibernate.type.Type;
import org.hibernate.type.TypeFactory;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Delegate that handles the type and join sequence information for a FromElement.
*
* @author josh Feb 12, 2005 10:17:34 AM
*/
class FromElementType {
private static final Log log = LogFactory.getLog( FromElementType.class );
private FromElement fromElement;
private EntityType entityType;
private EntityPersister persister;
private QueryableCollection queryableCollection;
private CollectionPropertyMapping collectionPropertyMapping;
private JoinSequence joinSequence;
private String collectionSuffix;
public FromElementType(FromElement fromElement, EntityPersister persister, EntityType entityType) {
this.fromElement = fromElement;
this.persister = persister;
this.entityType = entityType;
if ( persister != null ) {
fromElement.setText( ( ( Queryable ) persister ).getTableName() + " " + getTableAlias() );
}
}
private String getTableAlias() {
return fromElement.getTableAlias();
}
private String getCollectionTableAlias() {
return fromElement.getCollectionTableAlias();
}
public String getCollectionSuffix() {
return collectionSuffix;
}
public void setCollectionSuffix(String suffix) {
collectionSuffix = suffix;
}
public EntityPersister getEntityPersister() {
return persister;
}
public Type getDataType() {
if ( persister == null ) {
if ( queryableCollection == null ) {
return null;
}
return queryableCollection.getType();
}
else {
return entityType;
}
}
public Type getSelectType() {
if (entityType==null) return null;
boolean shallow = fromElement.getFromClause().getWalker().isShallowQuery();
return TypeFactory.manyToOne( entityType.getAssociatedEntityName(), shallow );
}
/**
* Returns the Hibernate queryable implementation for the HQL class.
*
* @return the Hibernate queryable implementation for the HQL class.
*/
public Queryable getQueryable() {
return ( persister instanceof Queryable ) ? ( Queryable ) persister : null;
}
/**
* Render the identifier select, but in a 'scalar' context (i.e. generate the column alias).
*
* @param i the sequence of the returned type
* @return the identifier select with the column alias.
*/
String renderScalarIdentifierSelect(int i) {
checkInitialized();
String[] cols = getPropertyMapping( EntityPersister.ENTITY_ID ).toColumns( getTableAlias(), EntityPersister.ENTITY_ID );
StringBuffer buf = new StringBuffer();
// For property references generate <tablealias>.<columnname> as <projectionalias>
for ( int j = 0; j < cols.length; j++ ) {
String column = cols[j];
if ( j > 0 ) {
buf.append( ", " );
}
buf.append( column ).append( " as " ).append( NameGenerator.scalarName( i, j ) );
}
return buf.toString();
}
/**
* Returns the identifier select SQL fragment.
*
* @param size The total number of returned types.
* @param k The sequence of the current returned type.
* @return the identifier select SQL fragment.
*/
String renderIdentifierSelect(int size, int k) {
checkInitialized();
// Render the identifier select fragment using the table alias.
if ( fromElement.getFromClause().isSubQuery() ) {
// TODO: Replace this with a more elegant solution.
String[] idColumnNames = ( persister != null ) ?
( ( Queryable ) persister ).getIdentifierColumnNames() : new String[0];
StringBuffer buf = new StringBuffer();
for ( int i = 0; i < idColumnNames.length; i++ ) {
buf.append( fromElement.getTableAlias() ).append( '.' ).append( idColumnNames[i] );
if ( i != idColumnNames.length - 1 ) buf.append( ", " );
}
return buf.toString();
}
else {
if (persister==null) {
throw new QueryException( "not an entity" );
}
String fragment = ( ( Queryable ) persister ).identifierSelectFragment( getTableAlias(), getSuffix( size, k ) );
return trimLeadingCommaAndSpaces( fragment );
}
}
private String getSuffix(int size, int sequence) {
return generateSuffix( size, sequence );
}
private static String generateSuffix(int size, int k) {
String suffix = size == 1 ? "" : Integer.toString( k ) + '_';
return suffix;
}
private void checkInitialized() {
fromElement.checkInitialized();
}
/**
* Returns the property select SQL fragment.
* @param size The total number of returned types.
* @param k The sequence of the current returned type.
* @return the property select SQL fragment.
*/
String renderPropertySelect(int size, int k, boolean allProperties) {
checkInitialized();
if ( persister == null ) {
return "";
}
else {
String fragment = ( ( Queryable ) persister ).propertySelectFragment(
getTableAlias(),
getSuffix( size, k ),
allProperties
);
return trimLeadingCommaAndSpaces( fragment );
}
}
String renderCollectionSelectFragment(int size, int k) {
if ( queryableCollection == null ) {
return "";
}
else {
if ( collectionSuffix == null ) {
collectionSuffix = generateSuffix( size, k );
}
String fragment = queryableCollection.selectFragment( getCollectionTableAlias(), collectionSuffix );
return trimLeadingCommaAndSpaces( fragment );
}
}
public String renderValueCollectionSelectFragment(int size, int k) {
if ( queryableCollection == null ) {
return "";
}
else {
if ( collectionSuffix == null ) {
collectionSuffix = generateSuffix( size, k );
}
String fragment = queryableCollection.selectFragment( getTableAlias(), collectionSuffix );
return trimLeadingCommaAndSpaces( fragment );
}
}
/**
* This accounts for a quirk in Queryable, where it sometimes generates ', ' in front of the
* SQL fragment. :-P
*
* @param fragment An SQL fragment.
* @return The fragment, without the leading comma and spaces.
*/
private static String trimLeadingCommaAndSpaces(String fragment) {
if ( fragment.length() > 0 && fragment.charAt( 0 ) == ',' ) {
fragment = fragment.substring( 1 );
}
fragment = fragment.trim();
return fragment.trim();
}
public void setJoinSequence(JoinSequence joinSequence) {
this.joinSequence = joinSequence;
}
public JoinSequence getJoinSequence() {
if ( joinSequence != null ) {
return joinSequence;
}
// Class names in the FROM clause result in a JoinSequence (the old FromParser does this).
if ( persister instanceof Joinable ) {
Joinable joinable = ( Joinable ) persister;
return fromElement.getSessionFactoryHelper().createJoinSequence().setRoot( joinable, getTableAlias() );
}
else {
return null; // TODO: Should this really return null? If not, figure out something better to do here.
}
}
public void setQueryableCollection(QueryableCollection queryableCollection) {
if ( this.queryableCollection != null ) {
throw new IllegalStateException( "QueryableCollection is already defined for " + this + "!" );
}
this.queryableCollection = queryableCollection;
if ( !queryableCollection.isOneToMany() ) {
// For many-to-many joins, use the tablename from the queryable collection for the default text.
fromElement.setText( queryableCollection.getTableName() + " " + getTableAlias() );
}
}
public QueryableCollection getQueryableCollection() {
return queryableCollection;
}
/**
* Returns the type of a property, given it's name (the last part) and the full path.
*
* @param propertyName The last part of the full path to the property.
* @return The type.
* @0param propertyPath The full property path.
*/
public Type getPropertyType(String propertyName, String propertyPath) {
checkInitialized();
Type type = null;
// If this is an entity and the property is the identifier property, then use getIdentifierType().
// Note that the propertyName.equals( propertyPath ) checks whether we have a component
// key reference, where the component class property name is the same as the
// entity id property name; if the two are not equal, this is the case and
// we'd need to "fall through" to using the property mapping.
if ( persister != null && propertyName.equals( propertyPath ) && propertyName.equals( persister.getIdentifierPropertyName() ) ) {
type = persister.getIdentifierType();
}
else { // Otherwise, use the property mapping.
PropertyMapping mapping = getPropertyMapping( propertyName );
type = mapping.toType( propertyPath );
}
if ( type == null ) {
throw new MappingException( "Property " + propertyName + " does not exist in " +
( ( queryableCollection == null ) ? "class" : "collection" ) + " "
+ ( ( queryableCollection == null ) ? fromElement.getClassName() : queryableCollection.getRole() ) );
}
return type;
}
String[] toColumns(String tableAlias, String path, boolean inSelect) {
return toColumns( tableAlias, path, inSelect, false );
}
String[] toColumns(String tableAlias, String path, boolean inSelect, boolean forceAlias) {
checkInitialized();
PropertyMapping propertyMapping = getPropertyMapping( path );
// If this from element is a collection and the path is a collection property (maxIndex, etc.) then
// generate a sub-query.
if ( !inSelect && queryableCollection != null && CollectionProperties.isCollectionProperty( path ) ) {
Map enabledFilters = fromElement.getWalker().getEnabledFilters();
String subquery = CollectionSubqueryFactory.createCollectionSubquery(
joinSequence,
enabledFilters,
propertyMapping.toColumns( tableAlias, path )
);
if ( log.isDebugEnabled() ) {
log.debug( "toColumns(" + tableAlias + "," + path + ") : subquery = " + subquery );
}
return new String[]{"(" + subquery + ")"};
}
else {
if ( forceAlias ) {
return propertyMapping.toColumns( tableAlias, path );
}
else if ( fromElement.getWalker().getStatementType() == HqlSqlTokenTypes.SELECT ) {
return propertyMapping.toColumns( tableAlias, path );
}
else if ( fromElement.getWalker().getCurrentClauseType() == HqlSqlTokenTypes.SELECT ) {
return propertyMapping.toColumns( tableAlias, path );
}
else if ( fromElement.getWalker().isSubQuery() ) {
// for a subquery, the alias to use depends on a few things (we
// already know this is not an overall SELECT):
// 1) if this FROM_ELEMENT represents a correlation to the
// outer-most query
// A) if the outer query represents a multi-table
// persister, we need to use the given alias
// in anticipation of one of the multi-table
// executors being used (as this subquery will
// actually be used in the "id select" phase
// of that multi-table executor)
// B) otherwise, we need to use the persister's
// table name as the column qualification
// 2) otherwise (not correlated), use the given alias
if ( isCorrelation() ) {
if ( isMultiTable() ) {
return propertyMapping.toColumns( tableAlias, path );
}
else {
return propertyMapping.toColumns( extractTableName(), path );
}
}
else {
return propertyMapping.toColumns( tableAlias, path );
}
}
else {
String[] columns = propertyMapping.toColumns( path );
log.trace( "Using non-qualified column reference [" + path + " -> (" + ArrayHelper.toString( columns ) + ")]" );
return columns;
}
}
}
private boolean isCorrelation() {
FromClause top = fromElement.getWalker().getFinalFromClause();
return fromElement.getFromClause() != fromElement.getWalker().getCurrentFromClause() &&
fromElement.getFromClause() == top;
}
private boolean isMultiTable() {
// should be safe to only ever expect EntityPersister references here
return fromElement.getQueryable() != null &&
fromElement.getQueryable().isMultiTable();
}
private String extractTableName() {
// should be safe to only ever expect EntityPersister references here
return fromElement.getQueryable().getTableName();
}
PropertyMapping getPropertyMapping(String propertyName) {
checkInitialized();
if ( queryableCollection == null ) { // Not a collection?
return ( PropertyMapping ) persister; // Return the entity property mapping.
}
// If the property is a special collection property name, return a CollectionPropertyMapping.
if ( CollectionProperties.isCollectionProperty( propertyName ) ) {
if ( collectionPropertyMapping == null ) {
collectionPropertyMapping = new CollectionPropertyMapping( queryableCollection );
}
return collectionPropertyMapping;
}
if ( queryableCollection.getElementType().isAnyType() ) {
// collection of <many-to-any/> mappings...
// used to circumvent the component-collection check below...
return queryableCollection;
}
if ( queryableCollection.getElementType().isComponentType() ) {
// Collection of components.
if ( propertyName.equals( EntityPersister.ENTITY_ID ) ) {
return ( PropertyMapping ) queryableCollection.getOwnerEntityPersister();
}
}
return queryableCollection;
}
public boolean isCollectionOfValuesOrComponents() {
if ( persister == null ) {
if ( queryableCollection == null ) {
return false;
}
else {
return !queryableCollection.getElementType().isEntityType();
}
}
else {
return false;
}
}
public boolean isEntity() {
return persister != null;
}
}
|
