Update UserNames

How would you go about updating the usernames?

I tried it by updating aspnet_Users and Users tables, but I ran into two problems:

1. I successfully updated the UserName in aspnet_Users but then noticed the LowereUserName field so I thought I'd update it as well, but when I run           UPDATE aspnet_Users SET LoweredUserName =LOWER(UserName) 

I get

Cannot insert duplicate key row in object 'dbo.aspnet_Users' with unique index 'aspnet_Users_Index'.

I have no idea what this means... do I even need this field?

2.I created a view that I want to join with table Users and then update the UserName field but when I run

The message means you are trying to update a username to one that already exists.

I think the LoweredUserName field is the one that is actually used, so I would try to keep them in sync.

And you also need to update the Users table, which it looks like you are doing in the second query.

Are you trying to change them to something different based on a property of the profile? If so, then someone may have a value in that property field that is the same as a username that you already have.