Can there be more than one primary key in a database? If so why?

Question

This is with regard to MS Access.

Answer 1

no, there should only be 1 primary key...for each table..

Answer 2

Hi,

You can have only one primary key for a table in ms access. A key that links two tables is called a foreign key and a primary key that is made up of a combination of more than one column is called a composite key.

If you need to create data sorted in a different sequence to the prinmary but have faster access then using the "order By" statement, you can create an index over the table concerned.

I found this article:

http://www.ehow.com/how_13622_create-index-microsoft.html

that shows you how to create an index.

Hope this helps

Answer 3

I am not really sure about MS Access, but yes, there can be more than one primary key in a database. Especially, in RDBMS, you can have more than one primary key, mostly because of the reason that the primary key is a combination of two fields in your table. One key would serve the purpose in simple tables, but you need two keys if you want to join the tables with other tables in the databse, for reporting purposes.