Re: Confused about CASE

[Thomas Kellerer <spam_eater(at)gmx(dot)net>]

Adam Rich wrote on 01.03.2008 01:02:
> > "The data types of all the result expressions must be convertible to a
> > single output type."
>
> The type of the field pg_class.relkind appears to be "char" which is
> described in the notes as:
>
> The type "char" (note the quotes) is different from char(1) in that it 
> only uses one byte of storage. It is internally used in the system catalogs 
> as a poor-man's enumeration type.
>
> http://www.postgresql.org/docs/8.3/interactive/datatype-character.html
>
> But one would expect "char" to be "convertible" to text for the purposes
> of CASE.  Both implicit and explicit cast to text seems to work fine.

OK, I'm glad it boils down to a datatype issue ;)

My SQL frontend reported that column as char(1) so I didn't notice the subtle 
difference (actually the JDBC driver returns char, not "char") and tested it 
agains a table with (int, char(1)).

Using c.relkind::text works fine.

Thanks for all the answers

Thomas