I have an Excel file with the set of records and I have a database called UserTable with a set of records. what I'm doing is comparing both the records with the field called UserId. there are some fields with null values and some with values in UserTable. If I compare the Excel with the database(UserTable) record it has to fetch the updated one with values in all fields. I have changed

I tried this:

public class UpdateData
    {
        public void Update(List<UserTable> users, List<UserTable> mappeddata)
        {
            //var result = from values in mappeddata join values2 in users on values.UserId equals values2.UserId select values;
            var valuestobeupdated = from m1 in mappeddata
                          join m2 in users on m1.UserId equals m2.UserId
                          where m1.ManagerUserId != m2.ManagerUserId
                            || m1.Department != m2.Department
                            || m1.Title != m2.Title ||  m1.Email != m2.Email || m1.FirstName != m2.FirstName    
                          select m1;
            Console.WriteLine("Updated");

        }
    }

but this is case sensitive for example if UserId=A24070 in users && UserId=a24070 in mappeddata it doesn't match, same goes with other field. Is there a way to make it case insensitive for example I did this in another statement var userIdnotinTable=userIdinExcel.Except(userIdinTable, StringComparer.OrdinalIgnoreCase); is there any example available for this? or is there any other way to do this?

thanks!!!