[PHP] the opposite of a join?

[jd.pillion]

I have a company table and a contacts table.  In the contacts table, there
is a field called "companyID" which is a link to a row in the company table.

 

What is the easiest way to query the company table for all the company rows
whose ID is NOT linked to in the contact table? Basically, the opposite of a
join?

 

Thanks

 

J

 

[PHP] RE: the opposite of a join?

[jd.pillion]

> Hi J, 
> 
> 
> Checkout this,
> 
> 
> SELECT * FROM tbl_company where id not in (SELECT companyID from
> tbl_contacts)
> 
 
 
Brilliant! This is exactly what I was looking for, and is quite
logical/readable!  Thanks to everyone for the ideas!
 
J
 
 
 
 
 
 
> 
> 
> 
> 
> Regards,
> Lasitha Alawatta
> Application Developer
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> 
> -Original Message-
> From: John Pillion [mailto:[EMAIL PROTECTED] 
On Behalf Of
> [EMAIL PROTECTED]
> Sent: Wednesday, October 03, 2007 2:21 PM
> To: php-general@lists.php.net; [EMAIL PROTECTED]
> Subject: [PHP-DB] the opposite of a join?
> 
> I have a company table and a contacts table.  In the contacts table,
> there
> is a field called "companyID" which is a link to a row in the company
> table.
> 
>  
> 
> What is the easiest way to query the company table for all the company
> rows
> whose ID is NOT linked to in the contact table? Basically, the opposite
> of a
> join?
> 
>  
> 
> Thanks
> 
>  
> 
> J
> 
>  
> 
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