Re: SQL LEFT OUTER join

[Trevor Perry <trevor@xxxxxxxxxx>]

David,

There is not a matching record in the right file for every record in the
left file. I want all the records in the left file to be in my select,
regardless of the right file having a match. So, LEFT OUTER JOIN does that
part. 

But, the field I am needing from the right file is a character field, and it
defaults to NULL when the right record does not exist. The NULL is causing a
problem with a tool I am using, so I wanted to have the default for that
field be blanks.

Something like this:
Select l.memberid, l.name, r.employername
from members as l left
outer join employers as r
on l.employer = r.employer

Became this:
Select l.memberid, l.name, coalesce(r.employername, ' ')
from members as l
left outer join employers as r
on l.employer = r.employer

Thanks to Michael and Steve for that quick fix.
Trevor



On 3/7/08 5:14 AM, "David FOXWELL" <David.FOXWELL@xxxxxxxxx> wrote:

> Hi,
>
> I read the replies to this post and don't quite understand. I am quite new to
> SQL.
>
> I don't understand why u r selecting the records on the left but u need the
> fields on the right?
>
> Does this mean your instructions are something like :
> Select * from leftfile l LEFT OUTER JOIN rightfile r on l.key = r.key  -?
>
> Shouldn't they be :
> Select l.* from leftfile l LEFT OUTER JOIN rightfile r on l.key = r.key  -?
>
>
> Thanks
>
>
>
>
>
>
> -----Message d'origine-----
> De : midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx]
> De la part de Trevor Perry
> Envoyé : jeudi 6 mars 2008 16:59
> À : Midrange Systems Technical Discussion
> Objet : SQL LEFT OUTER join
>
> All,
>
> I am using a LEFT OUTER JOIN to get all records in the ~left~ file ­
> regardless of a record existing in the ~right~ file. It works well, apart from
> one thing.
>
> The field I need from the ~right~ file is being filled with NULL when there is
> no record there. I really would like blanks in that field rather than NULL.
>
> How do I do that?
>
> Thanks in advance,
> Trevor
> --
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