HHH-11957 : DB2 substring method needs to be exposed in DB297Dialect

(cherry picked from commit 385a18b11b)

hibernate-core/src/test/java/org/hibernate/test/hql/DB297SubStringFunctionsTest.java

@@ -0,0 +1,177 @@
+/*
+ * 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 javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.PersistenceException;
+
+import org.hibernate.cfg.Configuration;
+import org.hibernate.cfg.Environment;
+import org.hibernate.dialect.DB297Dialect;
+import org.hibernate.exception.SQLGrammarException;
+import org.hibernate.resource.jdbc.spi.StatementInspector;
+
+import org.hibernate.testing.RequiresDialect;
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.hibernate.testing.transaction.TransactionUtil.doInHibernate;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+/**
+ * DB2 has 2 functions for getting a substring: "substr" and "substring"
+ *
+ * @author Gail Badner
+ */
+@RequiresDialect(DB297Dialect.class)
+public class DB297SubStringFunctionsTest extends BaseCoreFunctionalTestCase {
+	private static final MostRecentStatementInspector mostRecentStatementInspector = new MostRecentStatementInspector();
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class[] {
+				AnEntity.class
+		};
+	}
+
+	@Override
+	protected void configure(Configuration configuration) {
+		super.configure( configuration );
+		configuration.getProperties().put( Environment.STATEMENT_INSPECTOR, mostRecentStatementInspector );
+	}
+
+	@Before
+	public void setup() {
+		AnEntity anEntity = new AnEntity();
+		anEntity.description = "A very long, boring description.";
+
+		doInHibernate(
+				this::sessionFactory, session -> {
+					session.persist( anEntity );
+				}
+		);
+	}
+
+	@After
+	public void cleanup() {
+		doInHibernate(
+				this::sessionFactory, session -> {
+					session.createQuery( "delete from AnEntity" ).executeUpdate();
+				}
+		);
+	}
+
+	@Test
+	@TestForIssue( jiraKey = "HHH-11957")
+	public void testSubstringWithStringUnits() {
+
+		mostRecentStatementInspector.clear();
+
+		doInHibernate(
+				this::sessionFactory, session -> {
+					String value = session.createQuery(
+							"select substring( e.description, 21, 11, octets ) from AnEntity e",
+							String.class
+					).uniqueResult();
+					assertEquals( "description", value );
+				}
+		);
+
+		assertTrue( mostRecentStatementInspector.mostRecentSql.contains( "substring(" ) );
+		assertTrue( mostRecentStatementInspector.mostRecentSql.contains( "octets" ) );
+	}
+
+	@Test
+	@TestForIssue( jiraKey = "HHH-11957")
+	public void testSubstringWithoutStringUnits() {
+
+		mostRecentStatementInspector.clear();
+
+		doInHibernate(
+				this::sessionFactory, session -> {
+					String value = session.createQuery(
+							"select substring( e.description, 21, 11 ) from AnEntity e",
+							String.class
+					).uniqueResult();
+					assertEquals( "description", value );
+				}
+		);
+		assertTrue( mostRecentStatementInspector.mostRecentSql.contains( "substr(" ) );
+	}
+
+	@Test
+	@TestForIssue( jiraKey = "HHH-11957")
+	public void testSubstrWithStringUnits() {
+
+		mostRecentStatementInspector.clear();
+
+		try {
+			doInHibernate(
+					this::sessionFactory, session -> {
+						String value = session.createQuery(
+								"select substr( e.description, 21, 11, octets ) from AnEntity e",
+								String.class
+						).uniqueResult();
+						assertEquals( "description", value );
+					}
+			);
+			fail( "Should have failed because substr cannot be used with string units." );
+		}
+		catch (PersistenceException expected) {
+			assertTrue( SQLGrammarException.class.isInstance( expected.getCause() ) );
+		}
+
+		assertTrue( mostRecentStatementInspector.mostRecentSql.contains( "substr(" ) );
+		assertTrue( mostRecentStatementInspector.mostRecentSql.contains( "octets" ) );
+	}
+
+	@Test
+	@TestForIssue( jiraKey = "HHH-11957")
+	public void testSubstrWithoutStringUnits() {
+
+		mostRecentStatementInspector.clear();
+
+		doInHibernate(
+				this::sessionFactory, session -> {
+					String value = session.createQuery(
+							"select substr( e.description, 21, 11 ) from AnEntity e",
+							String.class
+					).uniqueResult();
+					assertEquals( "description", value );
+				}
+		);
+		assertTrue( mostRecentStatementInspector.mostRecentSql.contains( "substr(" ) );
+	}
+
+	@Entity(name="AnEntity")
+	public static class AnEntity {
+		@Id
+		@GeneratedValue
+		private long id;
+		private String description;
+	}
+
+	private static class MostRecentStatementInspector implements StatementInspector {
+		private String mostRecentSql;
+
+		public String inspect(String sql) {
+			mostRecentSql = sql;
+			return sql;
+		}
+		private void clear() {
+			mostRecentSql = null;
+		}
+	}
+}