Update or Insert (multiple rows and columns) from subquery in PostgreSQL

Question

I'm trying to do something like this in postgres:

UPDATE table1 SET (col1, col2) = (SELECT col2, col3 FROM othertable WHERE othertable.col1 = 123);
INSERT INTO table1 (col1, col2) VALUES (SELECT col1, col2 FROM othertable)

But point 1 is not possible even with postgres 9.0 as mentioned in the docs (http://www.postgresql.org/docs/9.0/static/sql-update.html)

Also point 2 seems not working. i'm getting the following error: subquery must return only one column.

Hope somebody has a workaround for me. otherwise the queries will take a looot of time :(.

FYI: I'm trying to select different columns from several tables and store them into a temporary table, so that another application can easily fetch the prepared data.

score 232 · Accepted Answer · edited Sep 17 '10 at 16:14

232

For the UPDATE

Use:

UPDATE table1 
   SET col1 = othertable.col2,
       col2 = othertable.col3 
  FROM othertable 
 WHERE othertable.col1 = 123;

For the INSERT

Use:

INSERT INTO table1 (col1, col2) 
SELECT col1, col2 
  FROM othertable

You don't need the VALUES syntax if you are using a SELECT to populate the INSERT values.

edited Sep 17 '10 at 16:14

Milen A. Radev

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answered Sep 17 '10 at 15:47

OMG Ponies

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1

Is it possible to combine Update & Insert so that if one fails, the other will be used without throwing an error (independently for each row). I think that would be a more complete solution to the question (for example: http://stackoverflow.com/a/6527838/781695) – user Dec 24 '14 at 05:08

score 38 · Answer 2 · answered Feb 15 '16 at 19:34

38

OMG Ponies's answer works perfectly, but just in case you need something more complex, here is an example of a slightly more advanced update query:

UPDATE table1 
SET col1 = subquery.col2,
    col2 = subquery.col3 
FROM (
    SELECT t2.foo as col1, t3.bar as col2, t3.foobar as col3 
    FROM table2 t2 INNER JOIN table3 t3 ON t2.id = t3.t2_id
    WHERE t2.created_at > '2016-01-01'
) AS subquery
WHERE table1.id = subquery.col1;

answered Feb 15 '16 at 19:34

David Namenyi

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perfect. this works best wherein you need to pick a subset based on a condition involving the updated table itself. – mythicalcoder Dec 28 '17 at 09:06
@David Namenyi can you explain this query? – Chintan Pathak Sep 08 '19 at 00:38

score 17 · Answer 3 · edited Dec 15 '11 at 21:09

17

UPDATE table1 SET (col1, col2) = (col2, col3) FROM othertable WHERE othertable.col1 = 123;

edited Dec 15 '11 at 21:09

answered Sep 05 '11 at 14:20

Walter

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Update or Insert (multiple rows and columns) from subquery in PostgreSQL

3 Answers3

For the UPDATE

For the INSERT

Linked