Re: mysql foreign key syntax / tutorial
| From: | Torsten Roehr | Date: | Wed, 21 Apr 2004 21:13:52 +0000 |
| Subject: | Re: mysql foreign key syntax / tutorial | ||
| References: | 1 | Groups: | php.db |
| Request: | Send a blank email to php-db+get-34027@lists.php.net to get a copy of this message | ||
"Uzi Klein" <uzi@bmby.com> wrote in message
news:005901c427ed$526e76c0$f805a8c0@p4...
> Hi.
>
> Any body got an idea how to use hte foreign keys in mysql innodb tables
> and how whould the change affect the performance of the server?
>
> lets say i have Items table, Clients table, and Sales table
> the Sales table always stores ClientID and ItemID
> but not every client/item is there
> a sale can be deleted without harming the client
> nor the item.
>
> i guess (not sure at all) it should go like :
>
> ALTER TABLE Sales
> ADD FOREIGN KEY ClientID(ClientID)
> REFERENCES Clients(ClientID)
> ON DELETE RESTRICT;
>
> ALTER TABLE Sales
> ADD FOREIGN KEY ItemID(ItemID)
> REFERENCES Items(ItemID)
> ON DELETE RESTRICT;
>
> Am I correct?
>
> thanks.
Take a look here:
http://dev.mysql.com/doc/mysql/en/InnoDB_foreign_key_constraints.html
Regards,
Torsten Roehr