Re: Referencing named attribute in where clause doesn't work with 7.1.2?

Andreas Joseph Krogh writes:

> Hi, this is my first post to this list so please...
> I have problems getting this query to work, any ideas?
>
> select article.title_text_key,
> (select on_text.text_value from on_text where
>     on_text.text_key = title_text_key
>     AND NOT title_text_key is NULL
>     AND on_text.lang_id = (select code.id from code, code_group where
>          code.code_group_id = code_group.id
>           AND code_group.description = 'lang' AND code.code_key = 'lang.NO'
>           )
>     )
> as title_text_value from article where NOT title_text_value is NULL;
>
> ERROR:  Attribute 'title_text_value' not found

The select list is not in scope for the where clause.  Basically, the
order of processing and approximately the nesting of scopes is:

from -> where -> group -> having -> select -> order

Any names generated by an element on the right cannot be in scope in
elements on the left.  (In some cases it might work as a convenience
anyway, but not in your case.)

I think you might be better off writing this query as a proper join
anyway.

-- 
Peter Eisentraut   peter_e@gmx.net   http://funkturm.homeip.net/~peter