SQL Antipatterns

Objective: Establish Primary Key Conventions

The objective is to make sure every table has a primary key, but confusion about the nature of a primary key has resulted in an antipattern.

Everyone who has been introduced to database design knows that a primary key is an important, even mandatory, part of a table. This is true; primary keys are integral to good database design. A primary key is guaranteed to be unique over all rows in the table, so this is the logical mechanism to address individual rows and to prevent duplicate rows from being stored. A primary key is also referenced by foreign keys to create table associations.

The tricky part is choosing a column to serve as the primary key. The value of any attribute in most tables has ...