HI,
Does it make any sense to create an index on the primary key?
Ken
----- Original Message -----
From: "Paul DuBois" <[EMAIL PROTECTED]>
To: "Fournier Jocelyn [Presence-PC]" <[EMAIL PROTECTED]>;
<[EMAIL PROTECTED]>
Sent: Friday, July 06, 2001 3:49 PM
Subject: Re: Perhaps a stupid question about KEY...
> At 12:14 AM +0200 7/7/01, Fournier Jocelyn [Presence-PC] wrote:
> >Hi,
> >
> >Is there any structural difference between a PRIMARY KEY and a UNIQUE key
?
> >
> >Thanks ;)
> >
> >Jocelyn Fournier
> >Presence-PC
> >www.presence-pc.com
>
> They're mostly the same, with these differences:
>
> There can only be one PRIMARY KEY per table, whereas you can have multiple
> UNIQUE keys.
>
> Any columns in a PRIMARY KEY must be declared NOT NULL; UNIQUE keys do
> not have this restriction.
>
> --
> Paul DuBois, [EMAIL PROTECTED]
>
> ---------------------------------------------------------------------
> Before posting, please check:
> http://www.mysql.com/manual.php (the manual)
> http://lists.mysql.com/ (the list archive)
>
> To request this thread, e-mail <[EMAIL PROTECTED]>
> To unsubscribe, e-mail
<[EMAIL PROTECTED]>
> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
>
---------------------------------------------------------------------
Before posting, please check:
http://www.mysql.com/manual.php (the manual)
http://lists.mysql.com/ (the list archive)
To request this thread, e-mail <[EMAIL PROTECTED]>
To unsubscribe, e-mail <[EMAIL PROTECTED]>
Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
