HHH-15482 Add test for issue

Author: dreab8

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

@@ -0,0 +1,125 @@
+/*
+ * 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 java.util.List;
+
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.orm.junit.EntityManagerFactoryScope;
+import org.hibernate.testing.orm.junit.Jpa;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+import jakarta.persistence.Tuple;
+import jakarta.persistence.criteria.CriteriaBuilder;
+import jakarta.persistence.criteria.CriteriaQuery;
+import jakarta.persistence.criteria.Join;
+import jakarta.persistence.criteria.Root;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@Jpa(
+		annotatedClasses = {
+				SelectCaseTest.Address.class,
+				SelectCaseTest.Person.class
+		}
+)
+@TestForIssue(jiraKey = "HHH-15482")
+public class SelectCaseTest {
+
+	@BeforeEach
+	public void setUp(EntityManagerFactoryScope scope) {
+		scope.inTransaction(
+				entityManager -> {
+					Address address = new Address( "RM", "Via Fori Imperiali", "Roma" );
+					Person person = new Person( 1, "Roberto", 70, address );
+					entityManager.persist( address );
+					entityManager.persist( person );
+
+					Address address2 = new Address( "GR", "Via Roma", "Gradoli" );
+					Person person2 = new Person( 2, "Andrea", 50, address2 );
+					entityManager.persist( address2 );
+					entityManager.persist( person2 );
+				}
+		);
+	}
+
+	@Test
+	public void testSelectCaseStringExpressionReturningAnIntegerValues(EntityManagerFactoryScope scope) {
+		scope.inTransaction(
+				entityManager -> {
+					CriteriaBuilder cb = entityManager.getCriteriaBuilder();
+					CriteriaQuery<Tuple> criteriaQuery = cb.createTupleQuery();
+					Root<Person> personRoot = criteriaQuery.from( Person.class );
+
+					Join<Object, Object> secondaryJoin = personRoot.join( "address" );
+					criteriaQuery.multiselect(
+							cb.selectCase( secondaryJoin.get( "code" ) )
+									.when( "GR", personRoot.get( "age" ) )
+									.otherwise( cb.nullLiteral( Integer.class ) )
+									.alias( "person_age" )
+					).orderBy( cb.asc( personRoot.get( "id" ) ) );
+
+					List<Tuple> ages = entityManager.createQuery( criteriaQuery ).getResultList();
+					assertThat( ages.size() ).isEqualTo( 2 );
+					assertThat( ages.get( 0 ).get( "person_age" ) ).isNull();
+					assertThat( ages.get( 1 ).get( "person_age" ) ).isEqualTo( 50 );
+				}
+		);
+
+	}
+
+	@Entity
+	@Table(name = "PERSON_TABLE")
+	public class Person {
+
+		@Id
+		private int id;
+
+		private String name;
+
+		private Integer age;
+
+		@ManyToOne
+		private Address address;
+
+		public Person() {
+		}
+
+		public Person(int id, String name, Integer age, Address address) {
+			this.id = id;
+			this.name = name;
+			this.age = age;
+			this.address = address;
+		}
+	}
+
+	@Entity
+	@Table(name = "ADDRESS_TABLE")
+	public static class Address {
+
+		@Id
+		private String code;
+
+		private String street;
+
+		private String city;
+
+		public Address() {
+		}
+
+		public Address(String code, String street, String city) {
+			this.code = code;
+			this.street = street;
+			this.city = city;
+		}
+	}
+}