Question

I am designing my db tables in SQL Server 2005 and have come across a small design/architecture issue… I have my main Users table (username, password, lastlogin, etc.), but I also need to store 2 different user profiles, i.e. the profile data stored will be different between the two. I’ve put all the common user data into the Users table.

Do I create separate tables for Consumers and Marketers? And if so, should the primary key in these tables be [table-name]_UserID with a 1:1 relationship on Users_UserID?

Basically, upon registering, the user will be given the choice to register as a Consumer or Marketer. When a user logs in, the Users table will be queried, and their accompanying profile will be queried from either table.

I know this approach is messy, which is why I’ve come here to ask how best this can be achieved.

Thanks!

EDIT: Additionally, in the Users table I have a Users_UserType flag that will allow me to distinguish between users when they log in, hence knowing which Profile Table to query.

Answer 1

Your gut feeling is correct. You want to normalize your data. Using separate tables reduces data duplication, or empty/null columns.

Unfortunantly, with a reverse relationship like this, you won’t have a nice clean foreign key from User to Consumer or Marketer because it could be one table or another.

You would want to map a User_Id from the Consumer/Marketers table back to User though.

You could query it in a single query using left joins:

Select 
     u.*,
     c.*,
     m.*
     From Users u
        left join Consumers c on c.User_Id = u.ID
        left join Marketers m on m.User_Id = u.ID
     Where
        u.ID = @UserId