//$Id: SubqueryExpression.java 15240 2008-10-01 19:32:11Z [email protected] $
package org.hibernate.criterion;
import org.hibernate.Criteria;
import org.hibernate.EntityMode;
import org.hibernate.HibernateException;
import org.hibernate.engine.QueryParameters;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.engine.TypedValue;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.impl.CriteriaImpl;
import org.hibernate.loader.criteria.CriteriaJoinWalker;
import org.hibernate.loader.criteria.CriteriaQueryTranslator;
import org.hibernate.persister.entity.OuterJoinLoadable;
import org.hibernate.type.Type;
/**
* @author Gavin King
*/
public abstract class SubqueryExpression implements Criterion {
private CriteriaImpl criteriaImpl;
private String quantifier;
private String op;
private QueryParameters params;
private Type[] types;
private CriteriaQueryTranslator innerQuery;
protected Type[] getTypes() {
return types;
}
protected SubqueryExpression(String op, String quantifier, DetachedCriteria dc) {
this.criteriaImpl = dc.getCriteriaImpl();
this.quantifier = quantifier;
this.op = op;
}
protected abstract String toLeftSqlString(Criteria criteria, CriteriaQuery outerQuery);
public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
final SessionFactoryImplementor factory = criteriaQuery.getFactory();
final OuterJoinLoadable persister =
( OuterJoinLoadable ) factory.getEntityPersister( criteriaImpl.getEntityOrClassName() );
createAndSetInnerQuery( criteriaQuery, factory );
criteriaImpl.setSession( deriveRootSession( criteria ) );
CriteriaJoinWalker walker = new CriteriaJoinWalker(
persister,
innerQuery,
factory,
criteriaImpl,
criteriaImpl.getEntityOrClassName(),
criteriaImpl.getSession().getEnabledFilters(),
innerQuery.getRootSQLALias()
);
String sql = walker.getSQLString();
final StringBuffer buf = new StringBuffer( toLeftSqlString(criteria, criteriaQuery) );
if ( op != null ) {
buf.append( ' ' ).append( op ).append( ' ' );
}
if ( quantifier != null ) {
buf.append( quantifier ).append( ' ' );
}
return buf.append( '(' ).append( sql ).append( ')' )
.toString();
}
private SessionImplementor deriveRootSession(Criteria criteria) {
if ( criteria instanceof CriteriaImpl ) {
return ( ( CriteriaImpl ) criteria ).getSession();
}
else if ( criteria instanceof CriteriaImpl.Subcriteria ) {
return deriveRootSession( ( ( CriteriaImpl.Subcriteria ) criteria ).getParent() );
}
else {
// could happen for custom Criteria impls. Not likely, but...
// for long term solution, see HHH-3514
return null;
}
}
public TypedValue[] getTypedValues(Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException {
//the following two lines were added to ensure that this.params is not null, which
//can happen with two-deep nested subqueries
SessionFactoryImplementor factory = criteriaQuery.getFactory();
createAndSetInnerQuery(criteriaQuery, factory);
Type[] ppTypes = params.getPositionalParameterTypes();
Object[] ppValues = params.getPositionalParameterValues();
TypedValue[] tv = new TypedValue[ppTypes.length];
for ( int i=0; i<ppTypes.length; i++ ) {
tv[i] = new TypedValue( ppTypes[i], ppValues[i], EntityMode.POJO );
}
return tv;
}
/**
* Creates the inner query used to extract some useful information about types, since it is needed in both methods.
*
* @param criteriaQuery The criteria query
* @param factory The session factory.
*/
private void createAndSetInnerQuery(CriteriaQuery criteriaQuery, SessionFactoryImplementor factory) {
if ( innerQuery == null ) {
//with two-deep subqueries, the same alias would get generated for
//both using the old method (criteriaQuery.generateSQLAlias()), so
//that is now used as a fallback if the main criteria alias isn't set
String alias;
if ( this.criteriaImpl.getAlias() == null ) {
alias = criteriaQuery.generateSQLAlias();
}
else {
alias = this.criteriaImpl.getAlias() + "_";
}
innerQuery = new CriteriaQueryTranslator(
factory,
criteriaImpl,
criteriaImpl.getEntityOrClassName(), //implicit polymorphism not supported (would need a union)
alias,
criteriaQuery
);
params = innerQuery.getQueryParameters();
types = innerQuery.getProjectedTypes();
}
}
}
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