UPDATE delivery_order_items SET project_id = NULL WHERE project_id NOT IN (SELECT id FROM project);
UPDATE invoice SET project_id = NULL WHERE project_id NOT IN (SELECT id FROM project);
+DELETE FROM orderitems WHERE trans_id NOT IN (SELECT id FROM oe);
+
ALTER TABLE orderitems ADD FOREIGN KEY (trans_id) REFERENCES oe (id);
ALTER TABLE orderitems ADD FOREIGN KEY (project_id) REFERENCES project (id);
ALTER TABLE orderitems ADD FOREIGN KEY (pricegroup_id) REFERENCES pricegroup (id);