HHH-11236 - JPA hbm2ddl auto-generation creates ddl with invalid syntax for Unique Key with any MySQLDialect

Add replicating test case that works just fine

hibernate-core/src/test/java/org/hibernate/test/annotations/uniqueconstraint/UniqueConstraintThrowsConstraintViolationExceptionTest.java

@@ -0,0 +1,82 @@
+/*
+ * 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.annotations.uniqueconstraint;
+
+import javax.persistence.Basic;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.PersistenceException;
+import javax.persistence.Table;
+
+import org.hibernate.exception.ConstraintViolationException;
+
+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;
+import static org.junit.Assert.fail;
+
+/**
+ * @author Vlad Mihalcea
+ */
+@TestForIssue(jiraKey = "HHH-11236")
+public class UniqueConstraintThrowsConstraintViolationExceptionTest extends BaseCoreFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class[] { Customer.class };
+	}
+
+	@Test
+	public void testUniqueConstraintWithEmptyColumnName() {
+		doInHibernate( this::sessionFactory, session -> {
+			Customer customer1 = new Customer();
+			customer1.customerId = "123";
+			session.persist( customer1 );
+		} );
+		try {
+			doInHibernate( this::sessionFactory, session -> {
+				Customer customer1 = new Customer();
+				customer1.customerId = "123";
+				session.persist( customer1 );
+			} );
+			fail( "Should throw" );
+		}
+		catch ( PersistenceException e ) {
+			assertEquals(
+					ConstraintViolationException.class,
+					e.getCause().getClass()
+			);
+		}
+	}
+
+	@Entity
+	@Table(name = "CUSTOMER")
+	public static class Customer {
+
+		@Id
+		@GeneratedValue(strategy = GenerationType.AUTO)
+		@Column(name = "CUSTOMER_ACCOUNT_NUMBER")
+		public Long customerAccountNumber;
+
+		@Basic
+		@Column(name = "CUSTOMER_ID", unique = true)
+		public String customerId;
+
+		@Basic
+		@Column(name = "BILLING_ADDRESS")
+		public String billingAddress;
+
+		public Customer() {
+		}
+	}
+}

libraries.gradle

@@ -95,7 +95,7 @@ ext {
             hsqldb:          "org.hsqldb:hsqldb:2.3.2",
             derby:           "org.apache.derby:derby:10.11.1.1",
             postgresql:      'org.postgresql:postgresql:9.4-1202-jdbc41',
-            mysql:             'mysql:mysql-connector-java:5.1.38',
+            mysql:             'mysql:mysql-connector-java:6.0.5',
             mariadb:         'org.mariadb.jdbc:mariadb-java-client:1.1.7',
             oracle:          'com.oracle.ojdbc:ojdbc7:12.1.0.2.0',
             mssql:             'com.microsoft.sqlserver:mssql-jdbc:6.1.0.jre8',