Re: [Haskelldb-users] Cartesian product

[Bjorn B. <d00...@dt...>]

Thomas L. Bevan wrote:
> Thanks. I had a problem with the code below. It compiles but generates a 
> runtime exception.
> 
> Fail: user error (SqlError {seState = "E", seNativeError = 7, seErrorMsg = 
> "ERROR:  column \"username1\" does not exist\n"})
> 
> userIds = do
>  users <- table phpbb_users
>  group <- table phpbb_user_group
>  -- restrict (users!(U.user_id) .==. group!(G.user_id) )
>  project ( username << users!username #
>            user_email << users!user_email #
>            user_regdate << users!user_regdate #
>            group_id << group!group_id )
> 
> If I uncomment the restriction everything runs smoothly. I suspect that there 
> is a lacunae in the SQL generation code for cases where the JOIN is 
> unqualified.

Thanks for reporting this, it sure looks like a bug. I get the same 
thing with other joins without a restrict too, never tried that before. 
We'll look into it.

/Bjorn