LinQ to EF插入Mysql数据乱码如何解决？

            var db = new Entities();

            var username = txtLogin.Text;

            var res = db.users.Where((u) => u.name == username);

            user curuser;

            if (res.Count() > 0)

            {

                curuser = res.First();

            }

            else

            {

                curuser = new user();

                curuser.name = username;

                curuser.appendix = "";

                db.users.Add(curuser);

                db.SaveChanges();

            }