Re: using UID in DB

On Tue, Mar 30, 2010 at 02:18:53PM -0700, Tommy Pham wrote: > On Tue, Mar 30, 2010 at 2:04 PM, Paul M Foster <paulf@quillandmouse.com> wrote: > > On Tue, Mar 30, 2010 at 01:36:27PM -0700, Tommy Pham wrote: > > > >> Hi, > >> > >> I'm just wondering if anyone on this list using some type of > >> UID/UUID/GUID in any of the DB?  If so, what DBMS/RDBMS are you using > >> and how many rows do you have for the table(s) using it?  What data > >> type are you using for that column? > > > > If I understand you correctly, I use a single table, "users". Either > > MySQL or PostgreSQL (depending on the application). There is one record > > per user, and that record contains a serial/sequential ID, set by the > > system, a user ID which is varchar(8), email address which is > > varchar(255), username which is varchar(50) and a password which is > > varchar(32) and stored encrypted. > > > > Hi Paul, > > In the case of mysql, it would be UUID and the value would look like this: > > 22ea1df1-3c40-11df-ab7a-200cd91e08cf > > and the case of postgresql, > > A0EEBC99-9C0B-4EF8-BB6D-6BB9BD380A11 > {a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11} > a0eebc999c0b4ef8bb6d6bb9bd380a11 > > which is 36 CHAR length (including dashes not braces) and is not quite > like identity insert (autoincrement). You could store it as > binary(16) - in mysql - but you'll need to implement UDFs to convert > between binary & char. Is that what you're using? or Are you using an > INT type? Unless you have some compelling need to store a number like this, I don't see the need to. What I store is what is called in PostgreSQL a "serial" value. MySQL calls it "auto_increment". You store all the other values as a row, and the DBMS adds in the "auto_increment"/"serial" value for you. It's an integer, *usually* one larger than the last value entered. Paul -- Paul M. Foster