sql236

delete from
    titles_test
where
    titles_test.id not in (
        select
            t.minid
        from
            (
                select
                    min(id) minid
                from
                    titles_test
                group by
                    emp_no
            ) as t
    )

知识点 delete + where 可删除指定行

但要遵循mysql运行逻辑，假设要更新的表是A，不可以引用A的元素来更新A。

否则会报错：You can't specify target table 'CUP_TEST_CLASS_LIST' for update in FROM clause

解决方法：利用子查询创立一个派生表过渡即可