MySQL中这句sql语句有问题吗？为什么总报错

Question

UPDATE zqbp_contract SET zqbp_contract.yingshou_money = zqbp_con_m.yingshou_money WHERE zqbp_contract.contract_id = zqbp_con_m.con_id报错：[Err] 1054 - Unknown column 'zqbp_con_m.con_id' in 'where clause'表结构：zqbp_con_m表中有con_id字段， 截图发不上来

Answer 1

UPDATE zqbp_contract,zqbp_con_m SET zqbp_contract.yingshou_money = zqbp_con_m.yingshou_money WHERE zqbp_contract.contract_id = zqbp_con_m.con_id

Answer 2

update 语句中 update后面的，就好比select中的from，你用到的表都要加入的

Answer 3

UPDATE zqbp_contract SET zqbp_contract.yingshou_money = (SELECT zqbp_con_m.yingshou_money FROM zqbp_con_m WHERE zqbp_contract.contract_id = zqbp_con_m.con_id)