Re: Joining tables

[Christian Mack]

Roger Smith wrote:
> 
> Hey all, I have a db with many tables and each table has this field
> "machine_id" as a field.  I have the following statement:
> 
> $query = "SELECT * FROM birth,physical,deployment
>          WHERE( ($machine_id = birth.machine_id) OR
>                 ($machine_id=physical.machine_id) OR ($machine_id =
>                 deployment.machine_id))";
> and this doesn't return any information if the birth table had information
> in it but the physical table doesn't and the deployment table doesn't.
> Can you tell me what I am doing wrong and how I may correct it, thanks.
> 
> Roger R. Smith

Hi Roger

You must have at least one row in each of the tables to get out something, or you have to
use LEFT JOIN instead.

Tschau
Christian