+CREATE UNIQUE INDEX [IX_users_username] ON [dbo].[users]([username],[mail_host]) ON [PRIMARY]\r
+GO\r
+\r
+CREATE INDEX [IX_users_alias] ON [dbo].[users]([alias]) ON [PRIMARY]\r
+GO\r
+\r
+ALTER TABLE [dbo].[identities] ADD CONSTRAINT [FK_identities_user_id] \r
+ FOREIGN KEY ([user_id]) REFERENCES [dbo].[users] ([user_id])\r
+ ON DELETE CASCADE ON UPDATE CASCADE\r
+GO\r
+\r
+ALTER TABLE [dbo].[contacts] ADD CONSTRAINT [FK_contacts_user_id]\r
+ FOREIGN KEY ([user_id]) REFERENCES [dbo].[users] ([user_id])\r
+ ON DELETE CASCADE ON UPDATE CASCADE\r
+GO\r
+\r
+ALTER TABLE [dbo].[contactgroups] ADD CONSTRAINT [FK_contactgroups_user_id]\r
+ FOREIGN KEY ([user_id]) REFERENCES [dbo].[users] ([user_id])\r
+ ON DELETE CASCADE ON UPDATE CASCADE\r
+GO\r
+\r
+ALTER TABLE [dbo].[cache] ADD CONSTRAINT [FK_cache_user_id]\r
+ FOREIGN KEY ([user_id]) REFERENCES [dbo].[users] ([user_id])\r
+ ON DELETE CASCADE ON UPDATE CASCADE\r
+GO\r
+\r
+ALTER TABLE [dbo].[messages] ADD CONSTRAINT [FK_messages_user_id]\r
+ FOREIGN KEY ([user_id]) REFERENCES [dbo].[users] ([user_id])\r
+ ON DELETE CASCADE ON UPDATE CASCADE\r
+GO\r
+\r
+ALTER TABLE [dbo].[contactgroupmembers] ADD CONSTRAINT [FK_contactgroupmembers_contactgroup_id]\r
+ FOREIGN KEY ([contactgroup_id]) REFERENCES [dbo].[contactgroups] ([contactgroup_id])\r
+ ON DELETE CASCADE ON UPDATE CASCADE\r