选择比插入所需更多的列以用于 RETURNING 语句

Question

为了说明，下面是 Postgres 9.6 中的一些 table：

people
 id | name 
----+------
  1 | a
  2 | b
  3 | c
  4 | d

groups
 id | name 
----+-------
 10 | xxx
 20 | yyy
 30 | zzz

people_in_group
person_id | group_id
----------+-------
1         | 10
2         | 10

我想在 people_in_group 中插入多个值，并将组名 return 发送给我。我已经有了 person_id (2)。以下有效，但不 return 名称。

INSERT INTO people_in_group(person_id, group_id) 
  SELECT '2' AS person_id, id as group_id FROM groups 
  WHERE name IN ('xxx', 'yyy', 'not there') 
  ON CONFLICT DO NOTHING 
  RETURNING *;

如果我将 name 添加到 SELECT 子句，我将得到 INSERT has more expressions than target columns。有什么方法可以让 table return 组的 name 发给我（通过 RETURNING 子句）？我知道我传入了组名，但是上面的查询将无法插入 'xxx'（重复键）和 'not there'（没有这样的组），所以它只会 return 'yyy'。理想情况下，我希望能够知道某些 INSERTs 失败的原因，但我会尽力而为。

Answer 1

with i as (
    insert into people_in_group(person_id, group_id) 
    select '2' as person_id, id as group_id
    from groups 
    where name in ('xxx', 'yyy', 'not there') 
    on conflict do nothing 
    returning *
)
select i.person_id, i.group_id, g.name
from i inner join groups g on g.id = i.group_id

选择比插入所需更多的列以用于 RETURNING 语句

Selecting more columns than necessary for insert for use in RETURNING statement

postgresql

sql-insert

bulkinsert

sql-returning