如何在postgresql中的with子句之后使用delete子句？

Question

查询 1：

with table1 as (select * from table2) delete * from table1;

查询 2：

with table1 as (select * from table2) delete * from table1 where col1 = 'something';

以上两个查询执行后都返回错误？有人可以帮我吗？

Answer 1

根据评论区的问题陈述，您可以使用下面的查询来删除重复项

delete from rohilla a using rohilla b where a=b and a.ctid < b.ctid;

使用 with 子句，您可以执行以下操作来删除重复项。（如果整行重复，下面的 Col1 可以是任何列）

WITH x AS 
( 
         SELECT   col1, 
                  Min(ctid) AS min 
         FROM     rohilla 
         GROUP BY col1
         HAVING   Count(col1) > 1 ) 
DELETE 
FROM   rohilla b 
using  x 
WHERE  x.col1 = b.col1
AND    x.min <> b.ctid;

Answer 2

您不能从 Postgres 的 CTE 中删除。显然，我相信您知道您可以这样做：

delete from table2
    where col1 = 'something';

如果你想涉及 CTE，那么你可以使用某种过滤，通常是在主键上：

with table1 as (
      select * from table2
     )
delete from table2 t2 using
     table1 t1
     where t1.<primary key> = t2.<primary key> and
           t1.col1 = 'something';

如何在postgresql中的with子句之后使用delete子句？

How to use delete clause after with clause in postgresql?

sql

postgresql

duplicates

sql-delete