INSERT INTO … FROM SELECT … RETURNING id mappings

Question

I\'m using PostgreSQL 9.3.

I want to duplicate some of the db records. Since I\'m using an auto-increment pk id for the table, I want to get back the id mappings fro

Answer 1

if id column of posts generated by nextval('posts_id_seq'::regclass) you can manually call this function for every new row

with
sel as (
  SELECT id, title, nextval('posts_id_seq'::regclass) new_id
  FROM   posts
  WHERE  id IN (1,2)
),
ins as (
  INSERT INTO posts (id, title)
  SELECT new_id, title
  FROM sel
)
SELECT id, new_id
FROM sel

it'l works with any data, include non-unique title