in general, should every table in a database have an identity field to use as a PK?

Question

This seems like a duplicate even as I ask it, but I searched and didn\'t find it. It seems like a good question for SO -- even though I\'m sure I can find it on many blogs e

Answer 1

Recognize the distinction between an Identity field and a key... Every table should have a key, to eliminate the data corruption of inadvertently entering multiple rows that represent the same 'entity'. If the only key a table has is a meaningless surrogate key, then this function is effectively missing.

otoh, No table 'needs' an identity, and certainly not every table benefits from one... Examples are: A table with a short and functional key, a table which does not have any other table referencing it through a foreign Key, or a table which is in a one to zero-or-one relationship with another table... none of these need an Identity