Are there any good reasons to have a database table without an integer primary key?

Question

Although I\'m guilty of this crime, it seems to me there can\'t be any good reason for a table to not have an identity field primary key.

Pros: - whether you want to o

Answer 1

To be a properly normalised table, each row should only have a single identifiable key. Many tables will already have natural keys, such a unique invoice number. I agree, especially with storage being so cheap, there is little overhead in having an autonumber/identity key on all tables, but in this instance which is the real key.

Another area where I personally don't use this approach if for reference data, where typically we have a Description and a Value

Code, Description
'L', 'Live'
'O', 'Old'
'P', 'Pending'

In this situation making code a primary key ensures no duplicates, and is more human readable.