- added foreign keys in mssql DDL

SQL/mssql.initial.sql

@@ -261,3 +261,38 @@ GO
 CREATE  INDEX [IX_users_alias] ON [dbo].[users]([alias]) ON [PRIMARY]
 GO
 
+ALTER TABLE [dbo].[identities] ADD
+    FOREIGN KEY ([FK_identities_user_id]) REFERENCES [dbo].[users] ([user_id])
+    ON DELETE CASCADE ON UPDATE CASCADE
+GO
+
+ALTER TABLE [dbo].[contacts] ADD
+    FOREIGN KEY ([FK_contacts_user_id]) REFERENCES [dbo].[users] ([user_id])
+    ON DELETE CASCADE ON UPDATE CASCADE
+GO
+
+ALTER TABLE [dbo].[contactgroups] ADD
+    FOREIGN KEY ([FK_contactgroups_user_id]) REFERENCES [dbo].[users] ([user_id])
+    ON DELETE CASCADE ON UPDATE CASCADE
+GO
+
+ALTER TABLE [dbo].[cache] ADD
+    FOREIGN KEY ([FK_cache_user_id]) REFERENCES [dbo].[users] ([user_id])
+    ON DELETE CASCADE ON UPDATE CASCADE
+GO
+
+ALTER TABLE [dbo].[messages] ADD
+    FOREIGN KEY ([FK_messages_user_id]) REFERENCES [dbo].[users] ([user_id])
+    ON DELETE CASCADE ON UPDATE CASCADE
+GO
+
+ALTER TABLE [dbo].[contactgroupmembers] ADD
+    FOREIGN KEY ([FK_contactgroupmembers_contactgroup_id]) REFERENCES [dbo].[contactgroups] ([contactgroup_id])
+    ON DELETE CASCADE ON UPDATE CASCADE
+GO
+
+ALTER TABLE [dbo].[contactgroupmembers] ADD
+    FOREIGN KEY ([FK_contactgroupmembers_contact_id]) REFERENCES [dbo].[contacts] ([contact_id])
+    ON DELETE CASCADE ON UPDATE CASCADE
+GO
+