ALTER TABLE vn.invoiceOut ADD COLUMN IF NOT EXISTS customsAgentFk INT(11) DEFAULT NULL AFTER siiTrascendencyInvoiceOutFk;

ALTER TABLE vn.invoiceOut ADD CONSTRAINT invoiceOut_customsAgentFk FOREIGN KEY (customsAgentFk)
    REFERENCES vn.customsAgent (id) ON DELETE RESTRICT ON UPDATE CASCADE;

UPDATE vn.invoiceOut i
		JOIN vn.client c ON c.id = io.clientFk 
		JOIN vn.address a ON a.id = c.defaultAddressFk 
    SET i.customsAgentFk = a.customsAgentFk;