HHH-17908 Allow varchar for STRING enums on MySQL in schema validation

hibernate-core/src/main/java/org/hibernate/dialect/Dialect.java

@@ -236,6 +236,7 @@ import static org.hibernate.type.SqlTypes.TIME_WITH_TIMEZONE;
 import static org.hibernate.type.SqlTypes.TINYINT;
 import static org.hibernate.type.SqlTypes.VARBINARY;
 import static org.hibernate.type.SqlTypes.VARCHAR;
+import static org.hibernate.type.SqlTypes.isEnumType;
 import static org.hibernate.type.SqlTypes.isFloatOrRealOrDouble;
 import static org.hibernate.type.SqlTypes.isNumericOrDecimal;
 import static org.hibernate.type.SqlTypes.isVarbinaryType;
@@ -1609,6 +1610,9 @@ public abstract class Dialect implements ConversionContext, TypeContributor, Fun
 			|| isFloatOrRealOrDouble(typeCode1) && isFloatOrRealOrDouble(typeCode2)
 			|| isVarcharType(typeCode1) && isVarcharType(typeCode2)
 			|| isVarbinaryType(typeCode1) && isVarbinaryType(typeCode2)
+			// HHH-17908: Since the runtime can cope with enum on the DDL side,
+			// but varchar on the ORM expectation side, let's treat the types as equivalent
+			|| isEnumType( typeCode1 ) && isVarcharType( typeCode2 )
 			|| sameColumnType(typeCode1, typeCode2);
 	}
 

hibernate-core/src/test/java/org/hibernate/orm/test/schemavalidation/ExistingVarcharEnumColumnValidationTest.java

@@ -0,0 +1,112 @@
+package org.hibernate.orm.test.schemavalidation;
+
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.registry.StandardServiceRegistry;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.cfg.AvailableSettings;
+import org.hibernate.dialect.H2Dialect;
+import org.hibernate.dialect.MySQLDialect;
+import org.hibernate.tool.hbm2ddl.SchemaValidator;
+
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+import org.hibernate.testing.orm.junit.JiraKey;
+import org.hibernate.testing.orm.junit.RequiresDialect;
+import org.hibernate.testing.transaction.TransactionUtil;
+import org.hibernate.testing.util.ServiceRegistryUtil;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+
+import static jakarta.persistence.GenerationType.IDENTITY;
+
+@JiraKey("HHH-17908")
+@RequiresDialect( H2Dialect.class )
+@RequiresDialect( MySQLDialect.class )
+public class ExistingVarcharEnumColumnValidationTest extends BaseCoreFunctionalTestCase {
+
+	private StandardServiceRegistry ssr;
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class<?>[] { EntityE.class };
+	}
+
+	@Before
+	public void setUp() {
+		try {
+			tearDown();
+		}
+		catch (Exception ex) {
+			// ignore
+		}
+		TransactionUtil.doInHibernate( this::sessionFactory, session -> {
+			session.createNativeQuery(
+							"create table en (id integer not null, sign_position varchar(255) check (sign_position in ('AFTER_NO_SPACE','AFTER_WITH_SPACE','BEFORE_NO_SPACE','BEFORE_WITH_SPACE')), primary key (id))" )
+					.executeUpdate();
+		} );
+	}
+
+	@After
+	public void tearDown() {
+		TransactionUtil.doInHibernate( this::sessionFactory, session -> {
+			session.createNativeQuery( "drop table en cascade" ).executeUpdate();
+		} );
+	}
+
+	@Test
+	public void testEnumDataTypeSchemaValidator() {
+		ssr = ServiceRegistryUtil.serviceRegistryBuilder()
+				.applySetting( AvailableSettings.HBM2DDL_AUTO, "validate" )
+				.build();
+		try {
+			final MetadataSources metadataSources = new MetadataSources( ssr );
+			metadataSources.addAnnotatedClass( EntityE.class );
+
+			new SchemaValidator().validate( metadataSources.buildMetadata() );
+		}
+		finally {
+			StandardServiceRegistryBuilder.destroy( ssr );
+		}
+	}
+
+
+	@Entity(name = "en")
+	@Table(name = "en")
+	public static class EntityE {
+		@Id
+		@Column(name = "id", nullable = false, updatable = false)
+		private Integer id;
+
+		@Enumerated(EnumType.STRING)
+		@Column(name = "sign_position")
+		private SignPosition signPosition;
+
+		public Integer getId() {
+			return id;
+		}
+
+		public void setId(Integer id) {
+			this.id = id;
+		}
+
+		public SignPosition getSignPosition() {
+			return signPosition;
+		}
+
+		public void setSignPosition(SignPosition signPosition) {
+			this.signPosition = signPosition;
+		}
+	}
+
+	public enum SignPosition {
+		AFTER_NO_SPACE, AFTER_WITH_SPACE, BEFORE_NO_SPACE, BEFORE_WITH_SPACE
+	}
+}