错误原因

在同一语句中。不能先SELECT出同一表的某些值，在Update这个表

实例

错误实例

DELETE
FROM dupes
WHERE id NOT IN (SELECT MIN(id)
                 FROM dupes
                 GROUP BY name)

正确实例

DELETE
FROM dupes
WHERE id NOT IN (SELECT * FROM (SELECT MIN(id) FROM dupes GROUP BY name) z);