กด ปุ่ม search data gridview ไม่โชว์ค่ะ และไม่แสดง error ช่วยด้วยค่ะ T-T

protected void searchData()
    {
        string sql = "SELECT DISTINCT "
                     + "A.B_TYPE, A.B_YEAR, A.B_DIST, B1.GD_NAME AS Division, B2.GD_NAME AS Brand, B3.GD_NAME AS Gram, A.B_SOURCE, A.B_MAT_TYPE, A.B_DEST_cntry,"
                      + "A.b_ton1, A.b_baht1, A.b_ton2, A.b_baht2, A.b_ton3, A.b_baht3, A.b_ton4, A.b_baht4, A.b_ton5, A.b_baht5, A.b_ton6, A.b_baht6, A.b_ton7, A.b_baht7, A.b_ton8,"
                      + "A.b_baht8, A.b_ton9, A.b_baht9, A.b_ton10, A.b_baht10, A.b_ton11, A.b_baht11, A.b_ton12, A.b_baht12"
                      + " FROM MIS_BUDGET_AA3 AS A INNER JOIN "
                      + "[MIS_GEN_DETAILS ] AS B1 ON B1.GD_NO = A.B_DIV AND B1.GD_TYPE = 'div' INNER JOIN "
                      + "[MIS_GEN_DETAILS ] AS B2 ON B2.GD_NO = A.B_GROUP3 AND B2.GD_TYPE = 'MGRP3' INNER JOIN "
                      + "[MIS_GEN_DETAILS ] AS B3 ON B3.GD_NO = A.B_GROUP2 AND B3.GD_TYPE = 'MGRP2' "
                        + "WHERE B_TYPE=' " + ddlBudgetS.SelectedValue + "' AND B_YEAR='" + ddlYearS.SelectedValue
                        + "' AND B1.GD_NAME =' " + ddlDivisionS.SelectedValue + "' AND B_SOURCE =' " + ddlsourceS.SelectedValue
                        + "' AND B3.GD_NAME =' " + ddlgramS.SelectedValue + "' AND B2.GD_NAME =' " + ddlbrandS.SelectedValue
                        + "' AND B_MAT_TYPE =' " + ddlMS.SelectedValue+"'";

        SqlConnection con = new SqlConnection(con_string);
        SqlCommand cmd = new SqlCommand(sql,con);

        try {
            if (ddlBudgetS.SelectedValue!="")
            { cmd.Parameters.AddWithValue("@B_TYPE",ddlBudgetS.SelectedValue);
            }
            if (ddlbrandS.SelectedValue!= "")
            {
                cmd.Parameters.AddWithValue("@B_GROUP3",ddlbrandS.SelectedValue);
            }
            if (ddlgramS.SelectedValue!= "")
            {
                cmd.Parameters.AddWithValue("@B_GROUP2",ddlgramS.SelectedValue);
            }
            if (ddlMS.SelectedValue!= "")
            {
                cmd.Parameters.AddWithValue("@B_MAT_TYPE",ddlMS.SelectedValue);
            }
          if (ddlsourceS.SelectedValue!= "")
            {
                cmd.Parameters.AddWithValue("@B_SOURCE", ddlsourceS.SelectedValue);
            }
        if(ddlYearS.SelectedValue!=""){
                cmd.Parameters.AddWithValue("@B_YEAR",ddlYearS.SelectedValue);
       }
            if(ddlDivisionS.SelectedValue!=""){
                cmd.Parameters.AddWithValue("@B_DIV",ddlDivisionS.SelectedValue);
            }
        if (con.State == ConnectionState.Open)
            {
                con.Close();
            }
            con.Open();

            SqlDataAdapter da = new SqlDataAdapter(sql,con);
            DataSet ds = new DataSet();
            da.Fill(ds, "Data");
            int count = ds.Tables["Data"].Rows.Count;
            if (count > 0)
            {
                gvSearch.DataSource = ds.Tables["Data"];
                gvSearch.DataBind();
            }
        
        }catch (Exception ex) { lblError.Text = ex.ToString(); }
        finally { con.Close(); }
    }

protected void btnsearch_Click(object sender, EventArgs e)
    {
      
       
           this.searchData();
      
    
    }