Comments on: The Meaning of Keys http://maggienelson.com/2009/02/the-meaning-of-keys/ databases and code goodness Thu, 01 Apr 2010 23:53:35 -0400 http://wordpress.org/?v=2.9.2 hourly 1 By: The Rules of (Software) Engagement - Maggie Nelson http://maggienelson.com/2009/02/the-meaning-of-keys/comment-page-1/#comment-200 The Rules of (Software) Engagement - Maggie Nelson Mon, 09 Mar 2009 02:45:44 +0000 http://maggienelson.com/?p=196#comment-200 [...] in how different databases implement standard SQL (I talked about this a little bit in a post about The Meaning of Keys). When you see something that Oracle has and MySQL and vice versa is sometimes tied to this [...] [...] in how different databases implement standard SQL (I talked about this a little bit in a post about The Meaning of Keys). When you see something that Oracle has and MySQL and vice versa is sometimes tied to this [...]

]]> By: Cal Evans http://maggienelson.com/2009/02/the-meaning-of-keys/comment-page-1/#comment-153 Cal Evans Mon, 23 Feb 2009 08:38:33 +0000 http://maggienelson.com/?p=196#comment-153 Hi Maggie! I totally agree with this statement: "A primary key only has one purpose: to uniquely identify a record in a table." I think it should be tattooed on every CS101 student to get the point across. I also totally agree with this statement: "As you can see: keys with meaning aren’t good or bad - they simply serve a purpose." On the surface, the may seem to be contradictory except for one key word in the first statement, PRIMARY. A primary key's sole function is to identify a record. it should have no meaning other than that. it's fine to have other keys that are unique to a record (email address, phone number, SSN, etc) but these should be considered CANDIDATE keys, not primary keys. Keys with meaning are fine. Primary keys with meaning will cause the space-time continuum to fold in on itself. :) IMHO, etc. =C= p.s. GREAT article, thanks for sharing. Hi Maggie!

I totally agree with this statement:

“A primary key only has one purpose: to uniquely identify a record in a table.” I think it should be tattooed on every CS101 student to get the point across.

I also totally agree with this statement:

“As you can see: keys with meaning aren’t good or bad – they simply serve a purpose.”

On the surface, the may seem to be contradictory except for one key word in the first statement, PRIMARY. A primary key’s sole function is to identify a record. it should have no meaning other than that. it’s fine to have other keys that are unique to a record (email address, phone number, SSN, etc) but these should be considered CANDIDATE keys, not primary keys.

Keys with meaning are fine. Primary keys with meaning will cause the space-time continuum to fold in on itself. :)

IMHO, etc.
=C=

p.s. GREAT article, thanks for sharing.

]]>