Database “key/ID” design ideas, Surrogate Key, Primary Key, etc

Question

So I\'ve seen several mentions of a surrogate key lately, and I\'m not really sure what it is and how it differs from a primary key.

I always assumed that ID was my prim

Answer 1

Wow, you opened a can of worms with this question. Database purists will tell you never to use surrogate keys (like you have above). On the other hand, surrogate keys can have some tremendous benefits. I use them all the time.

In SQL Server, a surrogate key is typically an auto-increment Identity value that SQL Server generates for you. It has NO relationship to the actual data stored in the table. The opposite of this is a Natural key. An example might be Social Security number. This does have a relationship to the data stored in the table. There are benefits to natural keys, but, IMO, the benefits to using surrogate keys outweigh natural keys.

I noticed in your example, you have a GUID for a primary key. You generally want to stay away from GUIDS as primary keys. The are big, bulky and can often be inserted into your database in a random way, causing major fragmentation.

Randy