From: Martijn Tonies
Date: January 5 2004 2:04pm
Subject: Re: Enum default values
List-Archive: http://lists.mysql.com/mysql/156847
Message-Id: <05ec01c3d394$c9798230$0e02a8c0@martijn>
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Hi,

> [snip]
> > If you insert an invalid value into an ENUM (that is, a string not
> > present in the list of allowed values), the empty string is inserted
> > instead as a special error value. This string can be distinguished
> from
> > a 'normal' empty string by the fact that this string has the numerical
> > value 0. More about this later.
>
> "changeday" is NOT NULL -> but you still can enter
> '' ... Strange and, IMO, a bug. What's the use of
> restricting to a set of possible values without enforcing it?
> [/snip]
>
> On an INSERT it allows you to get or track entry errors. You have to
> apply error checking to your application to enforce the integrity of the
> enum field.

So, basically, an ENUM has no real use when it comes to
checking its values?

>This has been one of those excessively debated issues over
> the years.

I sure hope so :-) ... I'm still new to MySQL though :-)

>I have used this 'feature' for error checking for a long time


With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL
Server.
Upscene Productions
http://www.upscene.com

> now.