ALTER TABLE costing_op_headers
    ADD COLUMN primary_data_set_id BIGINT UNSIGNED NULL AFTER style_number,
    ADD KEY idx_costing_op_primary_data (primary_data_set_id),
    ADD CONSTRAINT fk_costing_op_primary_data
        FOREIGN KEY (primary_data_set_id) REFERENCES costing_op_primary_data_sets (id);