C# ต้องการ query ค้นหาข้อมูลที่มีใน dataset ที่มี่อยู่แล้ว ต้องทำยังไงครับ ช่วยดูโค๊ดหน่อยครับ

    public partial class Form4 : Form
    {
        private DBConnect conn = new DBConnect();
        private DataSet dsDataGrid;
        private DataSet dsMaster;
        private MySqlDataAdapter daDataGrid;

        public Form4()
        {
            InitializeComponent();
        }

        private void cbDataYear_SelectedIndexChanged(object sender, EventArgs e)
        {
            string sql;
            if (this.cbDataYear.SelectedValue.ToString() != "")
            {
                sql = "select wy.year_th,wd.data_month,wd.service_date,wd.wbc_no,wd.birthday,wd.cid,wd.hn,cp.pname,concat(wd.fname,' ',wd.lname) as pt_name ";
                sql += " ,wc.case_name,thp.PROVINCE_NAME,tha.AMPHUR_NAME,thd.DISTRICT_NAME ";
                sql += " FROM wbc_data wd ";
                sql += " left outer join c_pname cp on wd.pname = cp.oid";
                sql += " left outer join wbc_case wc on wd.`case` = wc.oid";
                sql += " left outer join ref_thaiaddress_province thp on wd.chwpart = thp.PROVINCE_CODE";
                sql += " left outer join ref_thaiaddress_amphur tha on concat(wd.chwpart,wd.amppart) = tha.AMPHUR_CODE";
                sql += " left outer join ref_thaiaddress_district thd on concat(wd.chwpart,wd.amppart,wd.tmbpart) = thd.DISTRICT_CODE";
                sql += " left outer join wbc_year wy on wd.data_year = wy.year_en";
                sql += " where wd.data_year = '" + this.cbDataYear.SelectedValue.ToString() + "' ";
                sql += " ORDER BY wd.hn asc";
                loadDataToDataGrid(sql);
            }
        }

       
            public void loadDataToDataGrid(string sql) {
            MySqlCommand command;
            daDataGrid = new MySqlDataAdapter();

                conn.OpenConn();
                command = new MySqlCommand(sql, conn.OpenConn());
                dsDataGrid = new DataSet();
                daDataGrid.SelectCommand = command;
                daDataGrid.Fill(dsDataGrid,"wbc_data2");   
                conn.CloseConn();

                dataGridView1.DataSource = dsDataGrid;
                dataGridView1.DataMember = "wbc_data2";    //Error !!! Child list for field wbc_data cannot be created.

dataGridView1.Columns[0].HeaderText = "ข้อมูลปี";
                dataGridView1.Columns[1].HeaderText = "ข้อมูลเดือน";     ///Error !!! ->Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
                dataGridView1.Columns[2].HeaderText = "วันที่รับบริการ";
                dataGridView1.Columns[3].HeaderText = "wbc_no";
                dataGridView1.Columns[4].HeaderText = "วันเกิด";
                dataGridView1.Columns[5].HeaderText = "CID";
                dataGridView1.Columns[6].HeaderText = "HN";
                dataGridView1.Columns[7].HeaderText = "pname";
                dataGridView1.Columns[8].HeaderText = "pt_name";
                dataGridView1.Columns[9].HeaderText = "case_name";
                dataGridView1.Columns[10].HeaderText = "PROVINCE_NAME";
                dataGridView1.Columns[11].HeaderText = "AMPHUR_NAME";
                dataGridView1.Columns[12].HeaderText = "DISTRICT_NAME";
        }

          public void test(){

            MySqlDataAdapter daMaster = new MySqlDataAdapter();
            MySqlCommand command;
            string sql1,sql2;
            sql1 = "select wy.year_th,wd.data_month,wd.service_date,wd.wbc_no,wd.birthday,wd.cid,wd.hn,cp.pname,concat(wd.fname,' ',wd.lname) as pt_name ";
            sql1 += " ,wc.case_name,thp.PROVINCE_NAME,tha.AMPHUR_NAME,thd.DISTRICT_NAME ";
            sql1 += " FROM wbc_data wd ";
            sql1 += " left outer join c_pname cp on wd.pname = cp.oid";
            sql1 += " left outer join wbc_case wc on wd.`case` = wc.oid";
            sql1 += " left outer join ref_thaiaddress_province thp on wd.chwpart = thp.PROVINCE_CODE";
            sql1 += " left outer join ref_thaiaddress_amphur tha on concat(wd.chwpart,wd.amppart) = tha.AMPHUR_CODE";
            sql1 += " left outer join ref_thaiaddress_district thd on concat(wd.chwpart,wd.amppart,wd.tmbpart) = thd.DISTRICT_CODE";
            sql1 += " left outer join wbc_year wy on wd.data_year = wy.year_en";
            sql1 += " where wd.data_year = '2013' ";
            sql1 += " ORDER BY wd.hn asc";

            conn.OpenConn();
            command = new MySqlCommand(sql1, conn.OpenConn());
            dsMaster = new DataSet();

            daMaster.SelectCommand = command;
            daMaster.Fill(dsMaster, "wbc_data1");

            daMaster.Dispose();
            command.Dispose();
            conn.CloseConn();

            dataGridView1.Columns.Clear(); // <-- clear columns

            dataGridView1.DataSource = dsMaster;
            dataGridView1.DataMember = "wbc_data1";


        }
        
        private void Form4_Load(object sender, EventArgs e)
        {
            test();
        }
        
    }