Question

I’m starting to develop an application using MySQL and although I’ve developed apps before using databases, I’ve normally gone to the incrementing id method. The other day I was reading a posting somewhere and saw someone being picked apart for this, for not properly “normalising the database”. I’m not a big database person, but I wanted to make sure I’m doing this right.

Any ideas, help / guidance?

Answer 1

There are two main methods for picking a primary key:

• Selecting the primary key from existing natural candidate keys.
• Creating a surrogate key, and setting it as the primary key. Unlike a natural key, a surrogate key is not derived from application data. This is the type of key you were having with the auto incrementing method.

There are general advantages and disadvantages for both methods, and you may want to chose a natural key in some situations and a surrogate key in others.

I hope this serves as a brief introduction, so that you may be able to go further into your research on how to choose appropriate primary keys.