问存储过程在代码中返回所有内容，但在手动触发时返回一行

EN

        DataTable dt = new DataTable();
        using (SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["My_DB"].ConnectionString.ToString()))
        {
            using (SqlCommand cmd = new SqlCommand("sk.My_StoredProc", con))
            {
                using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                {
                    cmd.CommandType = CommandType.StoredProcedure;

                    //Add Parameter values
                    cmd.Parameters.Add("@StudentNumber", SqlDbType.VarChar).Value = studentNumber;
                    cmd.Parameters.Add("@StudentNameFragment", SqlDbType.VarChar).Value = studentNameFragment;
                    cmd.Parameters.Add("@SchoolYear", SqlDbType.VarChar).Value = this.schoolYr;

                    con.Open();
                    cmd.ExecuteNonQuery();

                    da.Fill(dt);
                }
            }
        }
        return dt;