/*
* 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.engine.internal;
import org.hibernate.engine.spi.Mapping;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.internal.util.StringHelper;
import org.hibernate.internal.util.collections.ArrayHelper;
import org.hibernate.persister.entity.Joinable;
import org.hibernate.persister.entity.OuterJoinLoadable;
import org.hibernate.persister.entity.PropertyMapping;
import org.hibernate.type.AssociationType;
/**
* Helper for dealing with joins.
*
* @author Gavin King
*/
public final class JoinHelper {
/**
* Get the qualified (prefixed by alias) names of the columns of the owning entity which are to be used in the join
*
* @param type The association type for the association that represents the join
* @param alias The left-hand side table alias
* @param property The index of the property that represents the association/join
* @param lhsPersister The persister for the left-hand side of the association/join
* @param mapping The mapping (typically the SessionFactory).
*
* @return The qualified column names.
*/
public static String[] getAliasedLHSColumnNames(
AssociationType type,
String alias,
int property,
OuterJoinLoadable lhsPersister,
Mapping mapping) {
return getAliasedLHSColumnNames( type, alias, property, 0, lhsPersister, mapping );
}
/**
* Get the unqualified names of the columns of the owning entity which are to be used in the join.
*
* @param type The association type for the association that represents the join
* @param property The name of the property that represents the association/join
* @param lhsPersister The persister for the left-hand side of the association/join
* @param mapping The mapping (typically the SessionFactory).
*
* @return The unqualified column names.
*/
public static String[] getLHSColumnNames(
AssociationType type,
int property,
OuterJoinLoadable lhsPersister,
Mapping mapping) {
return getLHSColumnNames( type, property, 0, lhsPersister, mapping );
}
/**
*
*/
/**
* Get the qualified (prefixed by alias) names of the columns of the owning entity which are to be used in the join
*
* @param associationType The association type for the association that represents the join
* @param columnQualifier The left-hand side table alias
* @param propertyIndex The index of the property that represents the association/join
* @param begin The index for any nested (composites) attributes
* @param lhsPersister The persister for the left-hand side of the association/join
* @param mapping The mapping (typically the SessionFactory).
*
* @return The qualified column names.
*/
public static String[] getAliasedLHSColumnNames(
AssociationType associationType,
String columnQualifier,
int propertyIndex,
int begin,
OuterJoinLoadable lhsPersister,
Mapping mapping) {
if ( associationType.useLHSPrimaryKey() ) {
return StringHelper.qualify( columnQualifier, lhsPersister.getIdentifierColumnNames() );
}
else {
final String propertyName = associationType.getLHSPropertyName();
if ( propertyName == null ) {
return ArrayHelper.slice(
toColumns( lhsPersister, columnQualifier, propertyIndex ),
begin,
associationType.getColumnSpan( mapping )
);
}
else {
//bad cast
return ( (PropertyMapping) lhsPersister ).toColumns( columnQualifier, propertyName );
}
}
}
private static String[] toColumns(OuterJoinLoadable persister, String columnQualifier, int propertyIndex) {
if ( propertyIndex >= 0 ) {
return persister.toColumns( columnQualifier, propertyIndex );
}
else {
final String[] cols = persister.getIdentifierColumnNames();
final String[] result = new String[cols.length];
for ( int j = 0; j < cols.length; j++ ) {
result[j] = StringHelper.qualify( columnQualifier, cols[j] );
}
return result;
}
}
/**
* Get the columns of the owning entity which are to be used in the join
*
* @param type The type representing the join
* @param property The property index for the association type
* @param begin ?
* @param lhsPersister The persister for the left-hand-side of the join
* @param mapping The mapping object (typically the SessionFactory)
*
* @return The columns for the left-hand-side of the join
*/
public static String[] getLHSColumnNames(
AssociationType type,
int property,
int begin,
OuterJoinLoadable lhsPersister,
Mapping mapping) {
if ( type.useLHSPrimaryKey() ) {
//return lhsPersister.getSubclassPropertyColumnNames(property);
return lhsPersister.getIdentifierColumnNames();
}
else {
final String propertyName = type.getLHSPropertyName();
if ( propertyName == null ) {
//slice, to get the columns for this component
//property
return ArrayHelper.slice(
property < 0
? lhsPersister.getIdentifierColumnNames()
: lhsPersister.getSubclassPropertyColumnNames( property ),
begin,
type.getColumnSpan( mapping )
);
}
else {
//property-refs for associations defined on a
//component are not supported, so no need to slice
return lhsPersister.getPropertyColumnNames( propertyName );
}
}
}
/**
* Determine the name of the table that is the left-hand-side of the join. Usually this is the
* name of the main table from the left-hand-side persister. But that is not the case with property-refs.
*
* @param type The type representing the join
* @param propertyIndex The property index for the type
* @param lhsPersister The persister for the left-hand-side of the join
*
* @return The table name
*/
public static String getLHSTableName(
AssociationType type,
int propertyIndex,
OuterJoinLoadable lhsPersister) {
if ( type.useLHSPrimaryKey() || propertyIndex < 0 ) {
return lhsPersister.getTableName();
}
else {
final String propertyName = type.getLHSPropertyName();
if ( propertyName == null ) {
//if there is no property-ref, assume the join
//is to the subclass table (ie. the table of the
//subclass that the association belongs to)
return lhsPersister.getSubclassPropertyTableName( propertyIndex );
}
else {
//handle a property-ref
String propertyRefTable = lhsPersister.getPropertyTableName( propertyName );
if ( propertyRefTable == null ) {
//it is possible that the tree-walking in OuterJoinLoader can get to
//an association defined by a subclass, in which case the property-ref
//might refer to a property defined on a subclass of the current class
//in this case, the table name is not known - this temporary solution
//assumes that the property-ref refers to a property of the subclass
//table that the association belongs to (a reasonable guess)
//TODO: fix this, add: OuterJoinLoadable.getSubclassPropertyTableName(String propertyName)
propertyRefTable = lhsPersister.getSubclassPropertyTableName( propertyIndex );
}
return propertyRefTable;
}
}
}
/**
* Get the columns of the associated table which are to be used in the join
*
* @param type The type
* @param factory The SessionFactory
*
* @return The columns for the right-hand-side of the join
*/
public static String[] getRHSColumnNames(AssociationType type, SessionFactoryImplementor factory) {
final String uniqueKeyPropertyName = type.getRHSUniqueKeyPropertyName();
final Joinable joinable = type.getAssociatedJoinable( factory );
if ( uniqueKeyPropertyName == null ) {
return joinable.getKeyColumnNames();
}
else {
return ( (OuterJoinLoadable) joinable ).getPropertyColumnNames( uniqueKeyPropertyName );
}
}
private JoinHelper() {
}
}