这个应该怎么解决 请老鸟们留步【新手】

1.连接数据库
2.把数据读到DataTable中
3.遍历DataTable表
        public static DataTable ExecuteDataTable(string sql, params SqlParameter[] parameters)
        {
            using (SqlConnection conn = new SqlConnection(connStr))
            {
                conn.Open();
                using (SqlCommand cmd = conn.CreateCommand())
                {
                     = sql;
                    cmd.Parameters.AddRange(parameters);

                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                    DataSet dataset = new DataSet();
                    adapter.Fill(dataset);
                    return dataset.Tables[0];
                }
            }
        }

        private void button3_Click(object sender, RoutedEventArgs e)
        {
            DataTable table = SqlHelper.ExecuteDataTable("select * from T_Students where volk=@volk",
                new SqlParameter("@volk", "汉"));
            foreach (DataRow row in table.Rows)
            {
                string name = (string)row["Name"];
                MessageBox.Show(name);
            }
}

好像这样就可以拉。。
select * from 学生管理数据库表 where rtrim(sex)='男' and rtrim(volk)='汉'