make sure tests drop tables

Signed-off-by: Lukas Jungmann <lukas.jungmann@oracle.com>
diff --git a/foundation/eclipselink.core.test/src/org/eclipse/persistence/testing/models/employee/relational/EmployeeSystem.java b/foundation/eclipselink.core.test/src/org/eclipse/persistence/testing/models/employee/relational/EmployeeSystem.java
index d51e826..33bb8ec 100644
--- a/foundation/eclipselink.core.test/src/org/eclipse/persistence/testing/models/employee/relational/EmployeeSystem.java
+++ b/foundation/eclipselink.core.test/src/org/eclipse/persistence/testing/models/employee/relational/EmployeeSystem.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2018 Oracle and/or its affiliates. All rights reserved.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
  * which accompanies this distribution.
@@ -50,6 +50,12 @@ public void createTables(DatabaseSession session) {
      * Drop table constraints
      */
     public void dropTableConstraints(Session session) {
+        if (session.getLogin().getPlatform().isMySQL()) {
+            try {
+                session.executeNonSelectingCall(new SQLCall("SET FOREIGN_KEY_CHECKS = 0"));
+            } catch (Exception e) {
+            }
+        }
         if (!SchemaManager.FAST_TABLE_CREATOR && !useFastTableCreatorAfterInitialCreate) {
             if (session.getLogin().getPlatform().isOracle()) {
                 try {
@@ -152,6 +158,12 @@ public void dropTableConstraints(Session session) {
             } catch (Exception e) {
             }
         }
+        if (session.getLogin().getPlatform().isMySQL()) {
+            try {
+                session.executeNonSelectingCall(new SQLCall("SET FOREIGN_KEY_CHECKS = 1"));
+            } catch (Exception e) {
+            }
+        }
     }
 
     /**
diff --git a/foundation/eclipselink.core.test/src/org/eclipse/persistence/testing/tests/history/HistoricalEmployeeSystem.java b/foundation/eclipselink.core.test/src/org/eclipse/persistence/testing/tests/history/HistoricalEmployeeSystem.java
index 96f64f9..21edb14 100644
--- a/foundation/eclipselink.core.test/src/org/eclipse/persistence/testing/tests/history/HistoricalEmployeeSystem.java
+++ b/foundation/eclipselink.core.test/src/org/eclipse/persistence/testing/tests/history/HistoricalEmployeeSystem.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2018 Oracle and/or its affiliates. All rights reserved.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
  * which accompanies this distribution.
@@ -76,6 +76,9 @@ public void createTables(DatabaseSession session) {
                 executeCall(session, "drop table EMPLOYEE CASCADE CONSTRAINTS");
                 executeCall(session, "drop table ADDRESS CASCADE CONSTRAINTS");
             } else {
+                if (session.getPlatform().isMySQL()) {
+                    executeCall(session, "SET FOREIGN_KEY_CHECKS = 0");
+                }
                 executeCall(session, "drop table PHONE");
                 executeCall(session, "drop table RESPONS");
                 executeCall(session, "drop table SALARY");
@@ -84,6 +87,9 @@ public void createTables(DatabaseSession session) {
                 executeCall(session, "drop table PROJECT");
                 executeCall(session, "drop table EMPLOYEE");
                 executeCall(session, "drop table ADDRESS");
+                if (session.getPlatform().isMySQL()) {
+                    executeCall(session, "SET FOREIGN_KEY_CHECKS = 1");
+                }
             }
         }