Question

我在Postgresql中遇到插入查询问题。

我有这样的查询：

select *
from (
  select *,
      row_number() over (partition by id order by id) as row_number
  from lookup_temp
     ) as rows
where row_number = 1

我希望将结果插入表lookup_temp。我怎么能这样做？

Answer 1

我假设您尝试插入lookup_temp，其中每个id只有一行重复 select （因为使用此select *,row_number() over (partition by id order by id) as row_numberfrom lookup_temp）到同一张桌子lookup_temp。如果是，下面的查询就足够了。

delete from lookup_temp where ctid in (
  select ctid from (
                  select ctid,
                  row_number() over (partition by id order by id) as row_number
                  from lookup_temp
                 ) as rows
  where row_number <> 1)

ctid

行表格中的行版本的物理位置。注意虽然ctid可用于非常快速地定位行版本，如果由VACUUM FULL更新或移动，则行的ctid将会更改。因此，ctid作为长期行标识符是无用的。 OID，或应该使用更好的用户定义的序列号来识别逻辑行。

Answer 2

您可以从SELECT执行INSERT以将结果导入lookup_temp表

INSERT into lookup_temp (specify your columns) VALUES
 (
  select *
  from (
       select *,
       row_number() over (partition by id order by id) as row_number
       from lookup_temp
       ) as rows
  where row_number = 1
 )

Answer 3

使用distinct on

，您的查询可以更简单

insert into lookup_temp
select distinct on (id) *
from lookup_temp

如果要插入另一个表，请指定列

insert into another_table (id, c1, c2...)
select distinct on (id) id, c1, c2...
from lookup_temp

http://www.postgresql.org/docs/current/static/sql-select.html#SQL-DISTINCT

Answer 4

- 就这样做吧。它应该工作正常

select *
INTO lookup_temp
from (
    select *, row_number() over (partition by id order by id) as row_number
    from lookup_temp
) as rows
where row_number = 1

将结果查询插入表中

4 个答案: