Re: Returning NULL to a set returning C type function

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

Bborie Park <bkpark(at)ucdavis(dot)edu> writes:
> I have a C type function that returns a set of a type.  The problem I 
> have is that the underlying function may return NULL.  When the 
> underlying function returns NULL, I get the error message:

> ERROR:  function returning set of rows cannot return null value

> I'm wondering what is the proper way to correct this problem?

Don't do that ;-).  You could choose either to not return any row
at all when this happens, or to construct an all-nulls row to return.
ExecMakeTableFunctionResult doesn't want to guess which behavior is
appropriate for your use-case, so it just complains.

			regards, tom lane