我有这个要求：
UPDATE PEOPLE SET ID_STATE = 5 WHERE ID_STATE IN (3,4);
我会提出相同的要求，但如果我不知道，ID_STATE只是labelStatePeople
SELECT ID_STATE FROM STATE_PEOPLE WHERE labelStatePeople = 'blue';
例子：
$1 = SELECT ID_STATE FROM STATE_PEOPLE WHERE labelStatePeople = 'blue';
$2 = SELECT ID_STATE FROM STATE_PEOPLE WHERE labelStatePeople = 'yellow';
$3 = SELECT ID_STATE FROM STATE_PEOPLE WHERE labelStatePeople = 'red';
最终要求： UPDATE PEOPLE SET ID_STATE = $1 WHERE ID_STATE IN ($2,$3);
只需有一个子查询即可返回那些陌生人的ID_STATE值：
UPDATE PEOPLE
SET ID_STATE = 5
WHERE ID_STATE IN (SELECT ID_STATE FROM STATE_PEOPLE
WHERE labelStatePeople = 'strange'
and ID_STATE IS NOT NULL)
（ID_STATE IS NOT NULL如果该列为，则可以删除子查询的一部分NOT NULL。）
本文收集自互联网，转载请注明来源。
如有侵权，请联系[email protected] 删除。
我来说两句