Re: cast needed - but where and why?

Steve Clark <sclark@netwolves.com> writes:
> I am getting the following error after upgrading from 7.4.6 to 8.3.6
> and can't figure out what is wrong. Any help would be greatly appreciated.
> 2009-04-02 10:45:10 EDT:srm2api:ERROR:  column "event_ref_log_no" is of type integer but expression is of type text
atcharacter 146 

I don't know ecpg very well, but if it doesn't provide any information
about parameter datatypes then the backend would resolve this:

    case  when  $7  > 0 then  $8  else null end

as producing a result of type "text".  7.4 would have allowed that to be
cast to int silently, but 8.3 won't (and the runtime cast involved
would've been expensive anyway).  I suggest sticking a cast directly
on the ambiguous parameter, ie

>             case     when :h_event_ref_log_no > 0
>                     then :h_event_ref_log_no :: integer
>                     else null end,

(You needn't cast the null, since the type attached to the other case
arm is a sufficient cue.)

            regards, tom lane