PostgreSQL DELETE FROM（SELECT * FROM table FETCH FIRST 10 ROWS ONLY）

Question

如何在postgreSQL中只删除几行？ 我想在子查询中获取要删除的10行。

我的表

Answer 1

您需要根据您的要求使用where条件，如下所示：

delete from mytable where id in(1,2,3,4,5,6,7,8,9,10)

或

delete from mytable where id in(select id from mytable where someconditon)

如果您想使用ctid删除前10名，可以尝试这样做：

DELETE FROM mytable 
WHERE ctid IN (
    SELECT ctid
    FROM mytable 
    GROUP BY s.serialId, s.valuetimestamp
    ORDER BY s.serialId
    LIMIT 10
)

如果您要删除表格中的重复项，请尝试以下操作：

DELETE FROM mytable
 WHERE ctid NOT IN
  (SELECT MAX(s.ctid)
    FROM table s
    GROUP BY s.serialId, s.valuetimestamp);

Answer 2

如果你有一些独特的标识符（序列号，让我们在你的表中调用它＆＃34; id＆＃34;），那么只需输入：

DELETE FROM table WHERE table.id IN (SELECT table.id FROM table WHERE *whatever*)

添加或不包含＆＃34; LIMIT 0,10＆＃34;