Thanks to both Martin and Aage.

Yes, Aage, I needed paranthesis around the expression in the CAST. I had
tried CASTing, too, and it didn't work. The parathesis helped.

Chuck

Aage Johansen wrote:

> Chuck Belanger wrote:
>
> > Hi, all:
> >
> > Is there any way to do a UNION and use the string operator || ?
> >
> > I found another way to do this. Its just to fill a combobox, but still
> > wondering why the problem.
> >
> > Each half of the UNION works fine on its own.
> >
> > I keep getting
> > SQL error code -104
> > Invalid command
> > Data type unknown
> >
> > for the following (its the field with || in it)
> >
> > select v1.ml_item || '/' || v2.ml_item as Root_Node ,
> > v1.ml_id as id,
> > v2.ml_parentid ,
> > v1.root_id
> > from masterlibrary v1, masterlibrary v2
> > where v1.root_id = v2.ml_parentid
> > and v1.ml_parentid = -1
> > UNION
> > select v3.ml_item || '/' as Root_Node ,
> > v3.ml_id as id,
> > v3.ml_parentid ,
> > v3.root_id
> > from masterlibrary v3
> > where v3.ml_id = v3.root_id
> > order by 1
>
> Try to cast both expessions to the same type.
>
> select cast(v1.ml_item || '/' || v2.ml_item as varchar(xxx)) Root_Node,
> ...
> union
> ...
> select cast(v3.ml_item || '/' as varchar(xxx)) Root_Node,
> ...
>
> - maybe you need some parentheseses(!) around the expressions.
>
> --
> Aage J.
>
>
>
> Yahoo! Groups Links
>
>
>
>