HHH-15106 - fk() SQM function

Author: sebersole

hibernate-core/src/main/java/org/hibernate/query/criteria/HibernateCriteriaBuilder.java

@@ -103,9 +103,12 @@ default <T> JpaCriteriaQuery<T> except(CriteriaQuery<? extends T> query1, Criter
 
 	<T> JpaCriteriaQuery<T> except(boolean all, CriteriaQuery<? extends T> query1, CriteriaQuery<?>... queries);
 
+
 	// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 	// Paths
 
+	<P, F> JpaExpression<F> fk(Path<P> path);
+
 	@Override
 	<X, T extends X> JpaPath<T> treat(Path<X> path, Class<T> type);
 

hibernate-core/src/main/java/org/hibernate/query/sqm/NodeBuilder.java

@@ -23,6 +23,7 @@
 import org.hibernate.query.criteria.JpaCompoundSelection;
 import org.hibernate.query.criteria.JpaExpression;
 import org.hibernate.query.criteria.JpaParameterExpression;
+import org.hibernate.query.criteria.JpaPath;
 import org.hibernate.query.criteria.JpaSearchedCase;
 import org.hibernate.query.criteria.JpaSelection;
 import org.hibernate.query.criteria.JpaSimpleCase;
@@ -146,6 +147,9 @@ <R> SqmTuple<R> tuple(
 	@Override
 	SqmPredicate wrap(Expression<Boolean>... expressions);
 
+	@Override
+	<P, F> SqmExpression<F> fk(Path<P> path);
+
 	@Override
 	<X, T extends X> SqmPath<T> treat(Path<X> path, Class<T> type);
 

hibernate-core/src/main/java/org/hibernate/query/sqm/internal/SqmCriteriaNodeBuilder.java

@@ -39,6 +39,7 @@
 import org.hibernate.metamodel.model.domain.spi.JpaMetamodelImplementor;
 import org.hibernate.query.ReturnableType;
 import org.hibernate.query.BindableType;
+import org.hibernate.query.SemanticException;
 import org.hibernate.query.sqm.BinaryArithmeticOperator;
 import org.hibernate.query.sqm.ComparisonOperator;
 import org.hibernate.query.sqm.NullPrecedence;
@@ -64,6 +65,8 @@
 import org.hibernate.query.sqm.tree.SqmTypedNode;
 import org.hibernate.query.sqm.tree.delete.SqmDeleteStatement;
 import org.hibernate.query.sqm.tree.domain.SqmBagJoin;
+import org.hibernate.query.sqm.tree.domain.SqmEntityValuedSimplePath;
+import org.hibernate.query.sqm.tree.domain.SqmFkExpression;
 import org.hibernate.query.sqm.tree.domain.SqmListJoin;
 import org.hibernate.query.sqm.tree.domain.SqmMapJoin;
 import org.hibernate.query.sqm.tree.domain.SqmPath;
@@ -132,6 +135,7 @@
 import jakarta.persistence.criteria.Selection;
 import jakarta.persistence.criteria.SetJoin;
 import jakarta.persistence.criteria.Subquery;
+import jakarta.persistence.metamodel.Bindable;
 
 import static java.util.Arrays.asList;
 import static org.hibernate.query.internal.QueryHelper.highestPrecedenceType;
@@ -342,6 +346,19 @@ public final SqmPredicate wrap(Expression<Boolean>... expressions) {
 		return new SqmJunctionPredicate( Predicate.BooleanOperator.AND, predicates, this );
 	}
 
+	@Override
+	public <P, F> SqmExpression<F> fk(Path<P> path) {
+		if ( path.getModel().getBindableType() != Bindable.BindableType.SINGULAR_ATTRIBUTE ) {
+			throw new SemanticException( "Path should refer to a to-one attribute : " + path );
+		}
+
+		if ( ! ( path instanceof SqmEntityValuedSimplePath ) ) {
+			throw new SemanticException( "Path should refer to a to-one attribute : " + path );
+		}
+
+		return new SqmFkExpression<>( (SqmEntityValuedSimplePath) path, this );
+	}
+
 	@Override
 	public <X, T extends X> SqmPath<T> treat(Path<X> path, Class<T> type) {
 		return ( (SqmPath<X>) path ).treatAs( type );

hibernate-core/src/test/java/org/hibernate/orm/test/query/criteria/NodeBuilderTests.java

@@ -0,0 +1,30 @@
+/*
+ * 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.orm.test.query.criteria;
+
+import org.hibernate.testing.orm.domain.StandardDomainModel;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Simple {@link org.hibernate.query.sqm.NodeBuilder} tests
+ *
+ * @author Steve Ebersole
+ */
+@DomainModel( standardModels = StandardDomainModel.RETAIL )
+@SessionFactory
+public class NodeBuilderTests {
+	@Test
+	public void testFkExpression(SessionFactoryScope scope) {
+		scope.inTransaction( (session) -> {
+			final String hql = "from Order o where fk(o.salesAssociate) = 1";
+			session.createSelectionQuery( hql ).getResultList();
+		} );
+	}
+}