表A name user owner
machine1 1 2
machine2 3 4
表B userid username
1 aaa
2 bbb
3 ccc
4 ddd
以上两个表,表A 设备的用户id和所有者id,表B是用户id对应的名称如何用sql语句显示为下面的表
显示为 name user ower
machine1 aaa bbb
machine2 ccc ddd
sql:
SELECT name
, user=(
SELECT username
FROM B
WHERE B.userid = A.user)
, owner=(
SELECT username
FROM B
WHERE B.userid = A.owner)
FROM A
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