select teachers and username, looking for mismatch of email and username
SELECT [TeacherId]
,[FirstName]
,[LastName]
, U.UserName
,[Salutation]
,[Email]
,[ProviderUserKey]
,[IsActive]
,[ImportId]
,[DisplayName]
,[DefaultLocation]
FROM [Teacher] T
JOIN [aspnet_Users] U on U.UserId = T.ProviderUserKey
where IsActive = 1
and u.UserName not like '%'+Substring(Email, 1,Charindex('@', Email)-1)+'%'
Order by LastName