我有“用户”
user_id usr_name email
1 john john@yahoo.com
2 mike mike@gmail.com
3 tom tom@hotmail.com
表“职位”
pod_id pos_name magic_id email
1 carpenter 22 mike@gmail.com
2 driver 33
3 guard 44 john@yahoo.com
4 cleaner 55 tom@hotmail.com
5 accountant 66
现在在表用户中我创建了列“magic_id”
有没有办法通过单个查询从表位置添加它?
e.g。
UPDATE users
LEFT JOIN positions on positions.email = users.email
SET users.magic_id = positions.magic_id
这会有用吗?
答案 0 :(得分:0)
这可以在这个SQLFiddle链接中看到:
http://sqlfiddle.com/#!2/431a9/1
UPDATE users
LEFT OUTER JOIN positions ON
positions.email = users.email
SET
users.magic_id = positions.magic_id;