Обсуждение: Converting query to view - duplicate fields

Hello,

Trying to convert the query below to a view. The problem is
despite it working as a query when trying to save it as a
view  the database returns the error that the field tablealias.cmpname
is duplicated. (Which it is and has to be)

So how to a refer to the same table more than once and
get the data without getting the above error. (Basically it
is looking up different addresses depending on the codes
stored in mhdespatch table). Can I do this with a view, or
do I have to create several views and link them together.

Thanks

Richard
Postgresql 7.4.1,SuSE 8.1

Query Begins ==>

CREATE OR REPLACE VIEW public.test AS
SELECT mhdespatch.gdn, mhdespatch.date, mhdespatch.remarks, 
mhdespatch.sp_instruct1,
mhdespatch.sp_instruct2, mhdespatch.sp_instruct3, tbldelivery.cmpname,
tbldelivery.adds1, tbldelivery.adds2, tbldelivery.adds3, tbldelivery.town,
tbldelivery.county, tbldelivery.pcode, tbldelivery.country, tbldelivery.tel1,
mhdespatch.del_ref, tblsender.cmpname, mhdespatch.send_ref, 
tblhaulier.cmpname,
mhdespatch.haul_reg, mhdespatch.cov, tblhaulier.tel1
FROM mhdespatch
INNER JOIN tblfmna AS tblhaulier ON mhdespatch.haul_code = tblhaulier.code
INNER JOIN tblfmna AS tblsender ON mhdespatch.send_code = tblsender.code
INNER JOIN tblfmna AS tbldelivery ON mhdespatch.del_code = tbldelivery.code;

<=== Query Ends 

On Tue, 9 Mar 2004, Richard Grosse wrote:

> Trying to convert the query below to a view. The problem is
> despite it working as a query when trying to save it as a
> view  the database returns the error that the field tablealias.cmpname
> is duplicated. (Which it is and has to be)

You're going to need to use column aliases to alias (for example)
tbldeliver.cmpname, tblsender.cmpname, tblhaulier.cmpname to different
aliases in the view, perhaps
"tbldeliver.cmpname" "tblsender.cmpname" and "tblhaulier.cmpname"
(note the double quotes).

> CREATE OR REPLACE VIEW public.test AS
> SELECT mhdespatch.gdn, mhdespatch.date, mhdespatch.remarks,
> mhdespatch.sp_instruct1,
> mhdespatch.sp_instruct2, mhdespatch.sp_instruct3, tbldelivery.cmpname,
> tbldelivery.adds1, tbldelivery.adds2, tbldelivery.adds3, tbldelivery.town,
> tbldelivery.county, tbldelivery.pcode, tbldelivery.country, tbldelivery.tel1,
> mhdespatch.del_ref, tblsender.cmpname, mhdespatch.send_ref,
> tblhaulier.cmpname,
> mhdespatch.haul_reg, mhdespatch.cov, tblhaulier.tel1
> FROM mhdespatch
> INNER JOIN tblfmna AS tblhaulier ON mhdespatch.haul_code = tblhaulier.code
> INNER JOIN tblfmna AS tblsender ON mhdespatch.send_code = tblsender.code
> INNER JOIN tblfmna AS tbldelivery ON mhdespatch.del_code = tbldelivery.code;

At 02:17 10/03/2004, you wrote:
>On Tue, 9 Mar 2004, Richard Grosse wrote:
>
> > Trying to convert the query below to a view. The problem is
> > despite it working as a query when trying to save it as a
> > view  the database returns the error that the field tablealias.cmpname
> > is duplicated. (Which it is and has to be)
>
>You're going to need to use column aliases to alias (for example)
>tbldeliver.cmpname, tblsender.cmpname, tblhaulier.cmpname to different
>aliases in the view, perhaps
>"tbldeliver.cmpname" "tblsender.cmpname" and "tblhaulier.cmpname"
>(note the double quotes).

Great just what I needed to know. Works fine now :-)

Thanks

Richard