I would like to be able to remove a single Foo, without having to first remove all the associated data from the other 3 tables.  Or, I know the ID of the Foo I want to remove, so instead of running multiple queries to find the associated rows, lets just knock it out with a single, multi-table delete!

DELETE
  db.zap as z,
  db.baz as bz,
  db.bar as z,
  db.foo as f
FROM
  db.zap as b,
  db.baz as bz,
  db.bar as z,
  db.foo as f
WHERE
  b.baz_id = bz.id AND
  b.zap_id = z.id AND
  bz.foo_id = f.id AND
  z.foo_id = f.id AND
  f.id = ?

This will then remove the rows associated with the single Foo record I’ve referenced, in one fell swoop.

What I’ll be doing is going through some simple applications, and start modeling the tables and relationships, and intersperse some commentary where useful.  The discussion depends on interaction, and I’m of the opinion that a ‘good’ database designer can a) defend their design articulately and b) know when to concede a good point.

Database design is becoming organic.  Strict adherence to the normal forms isn’t required any longer.  Let me be clear though, denormalizing a table to make things easier for a developer is not a valid reason to denormalize.

The modeling tool I’ll be using for generating the images is MySQL Workbench.  Workbench is a very powerful tool, from the source of one of the most powerful (and used) databases today.  I cut my teeth on database design with DBDesigner4, whose creator went on to work for MySQL Workbench.

Stay tuned.