Question

I have this table Users
I need to sort select result by parameter, but I face a problem when I sort varchar fields
like userName field.
how can this be resolved ?

----------------------------------------
| userID | UserName | password |...... |
----------------------------------------
| int    | varchar  | varcahr  | ..... |

    declare @index varchar(100)
    set @index = 2
    select * From users
    order by case @index 
                            when 1 then Number
                            when 2 then CAST(LoginName AS INT)
                            Else Password
                End

Answer 1

cast number to char, not char to number

case @index
      WHEN 1 THEN RIGHT('0000000000'+ CAST(UserId AS VARCHAR(10)), 10)
      WHEN 2 THEN UserName -- or LoginName, maybe a typo ?
      ELSE Password
      end