>> But now, I have another problem in this context. If I use text in the
>> SELECT statement (so, that the final output gives me the name of the
>> selected variables, plus the year and the value) than I get this
>> error message: ERROR: failed to find conversion function from
>> "unknown" to text
>
> [squint...] Try casting those literals to text explicitly, ie
> SELECT 'pop_density'::text AS name. There's some code in there
> that makes this work for simple UNION cases, but maybe not so much
> for select with a left join and order by and limit inside a union :-(
You guys are really great! Yep, it works like that like a charm...
Thanks a lot for your help!