[mapguide-users] Is it possible to create join on join ?

[Dave Wilson]

For performance reasons if you are querying 2 tables on the same instance it's much faster to create a view in the database than do a second join which isn't currently supported anyway.

The use case that isn't currently handled is when you have 2 tables on 2 different database instances or even platforms. Although in some cases it's possible to implement a view on the database that queries both Oracle and SQL Server for example.

Dave

-----Original Message-----
From: mapguide-users-bounces at lists.osgeo.org [mailto:mapguide-users-bounces at lists.osgeo.org] On Behalf Of David Nuell
Sent: Wednesday, July 23, 2008 10:08 AM
To: mapguide-users at lists.osgeo.org
Subject: Re: [mapguide-users] Is it possible to create join on join ?


Krunoslav -

I do not believe that it is possible.  I also tried this a while back and
was frustrated that it could not be done.  One solution that was given was
to create a query that encapsulates all the records you want in all tables
then join that query to your initial table/file.

Cheers.


Krunoslav wrote:
>
> For example, 3 tables:
>
> Table1 <-> Table2 = Join1
>
> This is ok, i understand this. Is it possible to join Join1 with Table3 ?
>
> This are tables from OracleXE, and I can join first two tables, but when I
> create New Join, I cannot select this Join1 as primary join source. How to
> do this?
>

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