Problems with passing values Asp.net C#

Question

I’m having a problem when I’m going to assign the return of query for a variable of the type object she passes as null. I have other identical methods, and they work well, just the one that’s not passing the right value. I could see that the DbValue takes the right value, but at the time of assigning passes null. My code is like this:

public string getEmailUsuario(string loginRede)
        {
            object email = "";
            string Sql;

             Sql = "SELECT EMAIL FROM VIEW_ADUSERS_LAZ_BR WHERE LOGIN_REDE = @LOGIN";

            SqlConnection conn = new SqlConnection();
            conn.ConnectionString = ConfigurationManager.ConnectionStrings["ConnIntranet"].ConnectionString;
            SqlCommand cmd = new SqlCommand(Sql, conn);

            cmd.Parameters.AddWithValue("@LOGIN", loginRede);

            try
            {
                conn.Open();

                email = cmd.ExecuteScalar(); <--- Aqui dá o erro. Passa "null"

                if (email != DBNull.Value)
                {
                    return email.ToString();
                }

                return "Sem email";

            }
            catch (Exception e)
            {
                _MSGERROR = e.Message.ToString();
                return "Sem email";
            }
            finally { conn.Close(); }
        }

Answer 1

Deducing that your column LOGIN_REDE is varchar you should include the quotes in @LOGIN to make the comparison between varchars.

When you move the Query to the bank it will be executed like this:

SELECT EMAIL FROM VIEW_ADUSERS_LAZ_BR WHERE LOGIN_REDE = seulogin

Instead of:

"SELECT EMAIL FROM VIEW_ADUSERS_LAZ_BR WHERE LOGIN_REDE = @LOGIN"

Use:

"SELECT EMAIL FROM VIEW_ADUSERS_LAZ_BR WHERE LOGIN_REDE = '@LOGIN'"