Question

I have this clause:

SELECT *
  FROM picture p
 WHERE p.id IN (2, 1, 3)

When I execute it I get the 3 elements, but ordered by its ‘id’ (1,2,3).

What I want is to get the elements in base of the order I’m giving: 2,1,3.

Answer 1

When I execute it I get the 3 elements, but ordered by its ‘id’
(1,2,3).

Not really. You basically get an arbitrary order. No ORDER BY clause means no reliable order.

If you are building your SQL dynamically, you’ll have to do something like this:

SELECT *
FROM picture p
WHERE p.id IN (2, 1, 3)
ORDER BY CASE p.id
    WHEN 2 THEN 1
    WHEN 1 THEN 2
    WHEN 3 THEN 3
END