GizmoLA.com

I have a small project that involves an implementation of Joomla (a fork of the popular PHP/Mysql based content management system Mambo). I started with Mambo and during the time I was configuring the site, the core developers of Mambo left to create the Joomla project. The reasons for this are discussed on their OpenSourceMatters website.

Suffice it to say, I find an Entity Relationships diagram to be very helpful in understanding the architecture of a database driven application like Joomla. There wasn't one available, so I decided to reverse engineer the database, and created these diagrams, which break the core database down into a few functional areas.

UPDATED At one time my pdf version of this was hosted by Joomla, but in one of the many moves of source code, the links to it were broken. You can get the pdf with all the views here.

User and Security Subsystem


Backend (modularity and extensibility) Subsystem


Content and Presentation Subsystem


Banners


Logging

Sometimes I see people attempting to use VARCHARS or CHARS to store dates in their MySQL database application. This is really fighting against MySQL, which has a variety of interchangeable date types. Internally MySQL is storing dates as numbers, which allows it to do all sorts of nice arithmetic and comparisons with very little effort on your part. For example, when you use a mysql DATE column to store a date, you don't have to worry about sortation, or comparing that date to another DATE, because MySQL already understands how to do those things internally. A lot of people also don't realize that they can output a DATE column in just about any way they choose using the DATE_FORMAT function. This causes people to shy away from using DATE, DATETIME, TIME, or TIMESTAMP columns, when they really should.

Continue reading "Exploring Mysql CURDATE and NOW. The same but different."