ALTER TABLE request_rdo_replacements ADD COLUMN accrued_rdo_item_id INT DEFAULT NULL UNIQUE;
ALTER TABLE request_rdo_replacements ADD CONSTRAINT FOREIGN KEY (accrued_rdo_item_id) REFERENCES request_items (id);

ALTER TABLE request_rdo_replacements ADD COLUMN accrued_rdo_other DATE DEFAULT NULL;
ALTER TABLE request_rdo_replacements ADD KEY idx_accrued_rdo_other (accrued_rdo_other);

ALTER TABLE request_accrued_rdos DROP COLUMN been_taken;