grant access to database from entity framework

grantaccess.cs

var sql = "USE <DBNAME>;" +
          "create user [domain\\user] from login [domain\\user];" +
          "ALTER ROLE db_datareader ADD MEMBER [domain\\user] ;";           

            try
            {
                using (var ctx = new MyContext())
                {
                    Info($"Start Grant Acess to xx: {DateTime.Now}");
                    ctx.Database.ExecuteSqlCommand(sql);
                    Info($"End Grant Acess to xx: {DateTime.Now}");
                }
            }
            catch (Exception exc)
            {
                Error(exc);
            }