mysql update使用要update的字段查询

CREATE TABLE tmp_voucher
SELECT a.voucher_id
FROM voucher a, voucher_action b
WHERE a.stock_id = 50 AND a.status_id != 40 AND a.voucher_id = b.voucher_id AND b.action_id = 60
GROUP BY a.voucher_id

UPDATE voucher a, tmp_voucher b SET a.stock_id = 60
WHERE a.voucher_id = b.voucher_id

drop table tmp_voucher;



因为mysql不能直接update查询子句内的字段否则会报错“you can't specify target table 'xxxx' for update in from CLAUSE”