mysql把一个表的字段赋值到另一张表
有两个表用户表user表和用户积分表score表,两个表是一对一关系,score表有user_id字段关联了user表的id,现需求是score表即将废弃,需要将score表的字段num的值作为user表的字段score_num的值,
有以下SQL写法
UPDATE user,score SET user.score_num = score.num WHERE score.user_id = user.id
或者
UPDATE user set user.score_num = (SELECT score.num FROM score WHERE score.user_id = user.id)
或者
UPDATE user SET user.score_num = score.num FROM user INNER JOIN score on score.user_id = user.id