HHH-9182 Test and fix HQL rules to allow more expression types in aggregate functions

hibernate-core/src/main/antlr/hql.g

@@ -842,9 +842,9 @@ castedIdentPrimaryBase
     ;
 
 aggregate
-	: ( SUM^ | AVG^ | MAX^ | MIN^ ) OPEN! ( additiveExpression | selectStatement ) CLOSE! { #aggregate.setType(AGGREGATE); }
+	: ( SUM^ | AVG^ | MAX^ | MIN^ ) OPEN! ( concatenation | subQuery ) CLOSE! { #aggregate.setType(AGGREGATE); }
 	// Special case for count - It's 'parameters' can be keywords.
-	|  COUNT^ OPEN! ( STAR { #STAR.setType(ROW_STAR); } | ( ( DISTINCT | ALL )? ( path | collectionExpr | NUM_INT | caseExpression ) ) ) CLOSE!
+	|  COUNT^ OPEN! ( STAR { #STAR.setType(ROW_STAR); } | ( ( DISTINCT | ALL )? ( concatenation | subQuery ) ) ) CLOSE!
 	|  collectionExpr
 	;
 

hibernate-core/src/test/java/org/hibernate/test/hql/CountExpressionTest.java

@@ -0,0 +1,149 @@
+/*
+ * 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.test.hql;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import javax.persistence.CollectionTable;
+import javax.persistence.ElementCollection;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.MapKeyColumn;
+import javax.persistence.OneToMany;
+
+import org.hibernate.dialect.DerbyDialect;
+import org.hibernate.dialect.H2Dialect;
+
+import org.hibernate.testing.RequiresDialect;
+import org.hibernate.testing.SkipForDialect;
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+import org.junit.Test;
+
+import static org.hibernate.testing.transaction.TransactionUtil.doInHibernate;
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Christian Beikov
+ */
+public class CountExpressionTest extends BaseCoreFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class[] {
+			Document.class,
+			Person.class
+		};
+	}
+
+	@Override
+	protected void prepareTest() throws Exception {
+		doInHibernate( this::sessionFactory, session -> {
+			Document document = new Document();
+			document.setId( 1 );
+
+			Person p1 = new Person();
+			Person p2 = new Person();
+
+			p1.getLocalized().put(1, "p1.1");
+			p1.getLocalized().put(2, "p1.2");
+			p2.getLocalized().put(1, "p2.1");
+			p2.getLocalized().put(2, "p2.2");
+
+			document.getContacts().put(1, p1);
+			document.getContacts().put(2, p2);
+
+			session.persist(p1);
+			session.persist(p2);
+			session.persist(document);
+		} );
+	}
+
+	@Override
+	protected boolean isCleanupTestDataRequired() {
+		return true;
+	}
+
+	@Test
+	@TestForIssue(jiraKey = "HHH-9182")
+	@SkipForDialect(value = DerbyDialect.class, comment = "Derby can't cast from integer to varchar i.e. it requires an intermediary step")
+	public void testCountDistinctExpression() {
+		doInHibernate( this::sessionFactory, session -> {
+			List results = session.createQuery(
+				"SELECT " +
+				"	d.id, " +
+				"	COUNT(DISTINCT CONCAT(CAST(KEY(l) AS java.lang.String), 'test')) " +
+				"FROM Document d " +
+				"LEFT JOIN d.contacts c " +
+				"LEFT JOIN c.localized l " +
+				"GROUP BY d.id")
+			.getResultList();
+
+			assertEquals(1, results.size());
+			Object[] tuple = (Object[]) results.get( 0 );
+			assertEquals(1, tuple[0]);
+		} );
+	}
+
+	@Entity(name = "Document")
+	public static class Document {
+
+		private Integer id;
+		private Map<Integer, Person> contacts = new HashMap<>();
+
+		@Id
+		public Integer getId() {
+			return id;
+		}
+
+		public void setId(Integer id) {
+			this.id = id;
+		}
+
+		@OneToMany
+		@CollectionTable
+		@MapKeyColumn(name = "position")
+		public Map<Integer, Person> getContacts() {
+			return contacts;
+		}
+
+		public void setContacts(Map<Integer, Person> contacts) {
+			this.contacts = contacts;
+		}
+	}
+
+
+	@Entity(name = "Person")
+	public static class Person {
+
+		private Integer id;
+
+		private Map<Integer, String> localized = new HashMap<>();
+
+		@Id
+		@GeneratedValue
+		public Integer getId() {
+			return id;
+		}
+
+		public void setId(Integer id) {
+			this.id = id;
+		}
+
+		@ElementCollection
+		public Map<Integer, String> getLocalized() {
+			return localized;
+		}
+
+		public void setLocalized(Map<Integer, String> localized) {
+			this.localized = localized;
+		}
+	}
+
+}