parameterization is not working correctly for FROM queries

If I use the FROM syntax during an UPDATE statement, it seems that the parameterize of this library always assumes “text” event when it shouldn’t be. I have written a fully working example here: https://gist.github.com/nhumrich/d330d167b4650f32cc33cfcb992123c0

If you run a basic query where bar is a DOUBLE PRECISION column, everything works. But if you use this syntax instead, it says its text for some reason:

'UPDATE foo d SET bar=v.bar FROM (values ($1, $2)) as v(id,bar) WHERE d.id=v.id', ['abc', 4]

You get the following error form postgres:

error: column “bar” is of type double precision but expression is of type text

If I dont use parameters, and instead use the exact values in the query, it works perfectly, as expected. You can see this example in the gist. Obviously, “not using parameters” is not a workaround, because of sql injection.

[nhumrich]

PostgreSQL is what assumes text when nothing is giving it better information.

Thats fair. I did try other libraries in other languages though, like sqlalchemy (python, which has the same mapping problem as javascript), and none of them have this problem. I will look into this though.

[shaneosullivan]

I see the same issue but for UPDATE queries that use the CASE/WHEN syntax like

UPDATE test_repro
    SET
      num = (
        CASE
          WHEN id = $1 then $2
        END
      )
    WHERE id in ($3)
;

See the full script at https://gist.github.com/shaneosullivan/555419454e536823d6f56fbc04612096