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1 package org.hibernate.criterion;
3
4 import org.hibernate.Criteria;
5 import org.hibernate.HibernateException;
6 import org.hibernate.MappingException;
7 import org.hibernate.QueryException;
8 import org.hibernate.engine.SessionFactoryImplementor;
9 import org.hibernate.engine.TypedValue;
10 import org.hibernate.persister.collection.QueryableCollection;
11 import org.hibernate.persister.entity.Loadable;
12 import org.hibernate.persister.entity.PropertyMapping;
13 import org.hibernate.sql.ConditionFragment;
14 import org.hibernate.type.CollectionType;
15 import org.hibernate.type.Type;
16
17
22 public abstract class AbstractEmptinessExpression implements Criterion {
23
24 private static final TypedValue[] NO_VALUES = new TypedValue[0];
25
26 protected final String  propertyName;
27
28 protected AbstractEmptinessExpression(String propertyName) {
29 this.propertyName = propertyName;
30 }
31
32 protected abstract boolean excludeEmpty();
33
34 public final String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
35 String entityName = criteriaQuery.getEntityName( criteria, propertyName );
36 String actualPropertyName = criteriaQuery.getPropertyName( propertyName );
37 String sqlAlias = criteriaQuery.getSQLAlias( criteria, propertyName );
38
39 SessionFactoryImplementor factory = criteriaQuery.getFactory();
40 QueryableCollection collectionPersister = getQueryableCollection( entityName, actualPropertyName, factory );
41
42 String [] collectionKeys = collectionPersister.getKeyColumnNames();
43 String [] ownerKeys = ( ( Loadable ) factory.getEntityPersister( entityName ) ).getIdentifierColumnNames();
44
45 String innerSelect = "(select 1 from " + collectionPersister.getTableName()
46 + " where "
47 + new ConditionFragment().setTableAlias( sqlAlias ).setCondition( ownerKeys, collectionKeys ).toFragmentString()
48 + ")";
49
50 return excludeEmpty()
51 ? "exists " + innerSelect
52 : "not exists " + innerSelect;
53 }
54
55
56 protected QueryableCollection getQueryableCollection(String entityName, String propertyName, SessionFactoryImplementor factory)
57 throws HibernateException {
58 PropertyMapping ownerMapping = ( PropertyMapping ) factory.getEntityPersister( entityName );
59 Type type = ownerMapping.toType( propertyName );
60 if ( !type.isCollectionType() ) {
61 throw new MappingException(
62 "Property path [" + entityName + "." + propertyName + "] does not reference a collection"
63 );
64 }
65
66 String role = ( ( CollectionType ) type ).getRole();
67 try {
68 return ( QueryableCollection ) factory.getCollectionPersister( role );
69 }
70 catch ( ClassCastException cce ) {
71 throw new QueryException( "collection role is not queryable: " + role );
72 }
73 catch ( Exception e ) {
74 throw new QueryException( "collection role not found: " + role );
75 }
76 }
77
78 public final TypedValue[] getTypedValues(Criteria criteria, CriteriaQuery criteriaQuery)
79 throws HibernateException {
80 return NO_VALUES;
81 }
82
83 public final String toString() {
84 return propertyName + ( excludeEmpty() ? " is not empty" : " is empty" );
85 }
86 }
87 |
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