 
 CREATE TABLE skr_purchase_orders (
     id integer NOT NULL,
-    visible_id integer NOT NULL,
+    visible_id character varying NOT NULL,
     state smallint DEFAULT 0 NOT NULL,
     vendor_id integer NOT NULL,
     location_id integer NOT NULL,


CREATE TABLE skr_pick_tickets (
    id integer NOT NULL,
    visible_id integer NOT NULL,
    sales_order_id integer NOT NULL,
    location_id integer NOT NULL,
    shipped_at date,


CREATE TABLE skr_po_receipts (
    id integer NOT NULL,
    visible_id character varying NOT NULL,
    location_id integer NOT NULL,
    freight numeric(15,2) DEFAULT 0.0 NOT NULL,
    purchase_order_id integer NOT NULL,
