Technote Details :: User name column not unique
Issue
When attempting to login to a site created with MX Kollection 3 tools, although I enter the correct user name and password, I get an error message saying "More than one user found."

Reason
This happens because there are two records with the same username in the user database. The username table column has not been set as an Unique key, and therefore, it allows two records to have the same value. When the login operation retrieves the sure account details to check the password, it finds two (or more) matching records.
Solution
There are two solutions to this problem:
When you create the user table, add to the username column the UNIQUE KEY attribute. To find out how to do this, consult your particular database software.
If you need to have a non-unique key attribute for the username column, then the username field should be checked each time a new user is added. To add this check, use the server behavior. For more information on this server behavior, see the Check Unique Key page.