如何存储从SqlDataReader返回的结果？

Question

我是一个新手,正如我的问题所证明的那样,我正在使用datareader来查找与某个subId值相关联的行.我使用了一个while(dr.read)循环并在每种情况下与其他读者嵌套了一个switch case语句(下面的代码),但我抛出了异常"已经是一个与此命令关联的开放数据读取器,必须首先关闭它".有没有办法将第一个datareader的结果(subId = x的相关行)存储在数组或列表中,然后在我输入switch语句之前关闭该读取器？(我理解数组是什么程度,我想它会起作用,但我不知道语法会是什么样子).

string viewQuery = "SELECT ProductId FROM SubmissionProducts WHERE SubmissionId =" + x;



            using (SqlCommand viewcmd = new SqlCommand(viewQuery, editConn))
            {
                SqlDataReader dr = viewcmd.ExecuteReader();
                while (dr.Read())
                {
                    switch(dr.GetInt32(0))
                    {
                        case 1:
                            PanelEplShow.Visible = true;
                            using (SqlCommand eplviewcmd = new SqlCommand(epl, editConn))
                            {
                                SqlDataReader epldr = eplviewcmd.ExecuteReader();
                                epldr.Read();
                                LblEplShowEntity.Text = epldr.GetString(0);
                                LblEplShowTotalEmpl.Text = epldr.GetInt32(1).ToString();
                                LblEplShowCalEmpl.Text = epldr.GetInt32(2).ToString();
                                LblEplShowMichEmpl.Text = epldr.GetInt32(3).ToString();
                                LblEplShowNyEmpl.Text = epldr.GetInt32(4).ToString();
                                LblEplShowNjEmpl.Text = epldr.GetInt32(5).ToString();
                                LblEplShowPrimEx.Text = epldr.GetInt32(6).ToString();
                                LblEplShowLim.Text = epldr.GetInt32(7).ToString();
                                LblEplShowPrem.Text = epldr.GetInt32(8).ToString();
                                LblEplShowWage.Text = epldr.GetInt32(9).ToString();
                                LblEplShowInvestCost.Text = epldr.GetInt32(10).ToString();
                                epldr.Close();
                            }
                            break;
                        case 2:
                            PanelProfShow.Visible = true;
                            using (SqlCommand profcmd1 = new SqlCommand(prof, editConn))
                            {
                                SqlDataReader profdr = profcmd1.ExecuteReader();
                                profdr.Read();
                                LblProfShowPrimEx.Text = profdr.GetInt32(0).ToString();
                                LblProfShowType.Text = profdr.GetInt32(1).ToString();
                                LblProfShowLim.Text = profdr.GetInt32(2).ToString();
                                LblProfShowRetention.Text = profdr.GetInt32(3).ToString();
                                LblProfShowAtt.Text = profdr.GetInt32(4).ToString();
                                LblProfShowPrem.Text = profdr.GetInt32(5).ToString();
                                LblProfShowSublim.Text = profdr.GetInt32(5).ToString();
                                LblProfShowEntity.Text = profdr.GetInt32(6).ToString();
                                profdr.Close();
                            }
                            break;
                        case 3:
                            PanelCrimeShow.Visible = true;
                            using (SqlCommand crimcmd = new SqlCommand(crim, editConn))
                            {
                                SqlDataReader crimdr = crimcmd.ExecuteReader();
                                crimdr.Read();
                                LblCrimeShowEntity.Text = crimdr.GetString(0);
                                LblCrimeShowEmpl.Text = crimdr.GetInt32(1).ToString();
                                LblCrimeShowPrimEx.Text = crimdr.GetInt32(2).ToString();
                                LblCrimeShowLimA.Text = crimdr.GetInt32(3).ToString();
                                LblCrimeShowDedA.Text = crimdr.GetInt32(4).ToString();
                                LblCrimeShowPremA.Text = crimdr.GetInt32(5).ToString();
                                LblCrimeShowLimB.Text = crimdr.GetInt32(6).ToString();
                                LblCrimeShowDedB.Text = crimdr.GetInt32(7).ToString();
                                LblCrimeShowPremB.Text = crimdr.GetInt32(8).ToString();
                                crimdr.Close();
                            }
                            break;
                        case 4:
                            PanelFidShow.Visible = true;
                            using (SqlCommand fidcmd = new SqlCommand(fid, editConn))
                            {
                                SqlDataReader fiddr = fidcmd.ExecuteReader();
                                fiddr.Read();
                                LblFidShowEntity.Text = fiddr.GetString(0);
                                LblFidShowPrimEx.Text = fiddr.GetInt32(1).ToString();
                                LblFidShowLim.Text = fiddr.GetInt32(2).ToString();
                                LblFidShowSir.Text = fiddr.GetInt32(3).ToString();
                                LblFidShowAtt.Text = fiddr.GetInt32(4).ToString();
                                LblFidShowPrem.Text = fiddr.GetInt32(5).ToString();
                                LblFidShowSublim.Text = fiddr.GetInt32(6).ToString();
                                fiddr.Close();
                            }
                            break;
                        case 5:
                            PanelNotShow.Visible = true;
                            using (SqlCommand notcmd = new SqlCommand(not, editConn))
                            {
                                SqlDataReader notdr = notcmd.ExecuteReader();
                                notdr.Read();
                                LblNotShowPrimEx.Text = notdr.GetInt32(0).ToString();
                                LblNotShowCov.Text = notdr.GetInt32(1).ToString();
                                LblNotShowSharedLim.Text = notdr.GetInt32(2).ToString();
                                LblNotShowTradLim.Text = notdr.GetInt32(3).ToString();
                                LblNotShowTradSir.Text = notdr.GetInt32(4).ToString();
                                LblNotShowEplLim.Text = notdr.GetInt32(5).ToString();
                                LblNotShowEplSir.Text = notdr.GetInt32(6).ToString();
                                LblNotShowEplPrem.Text = notdr.GetInt32(7).ToString();
                                LblNotShowSublim.Text = notdr.GetInt32(8).ToString();
                                notdr.Close();
                            }
                            break;
                        case 6:
                            PanelPrivShow.Visible = true;
                            using (SqlCommand privcmd = new SqlCommand(priv, editConn))
                            {
                                SqlDataReader privdr = privcmd.ExecuteReader();
                                privdr.Read();
                                LblPrivShowPrimEx.Text = privdr.GetInt32(0).ToString();
                                LblPrivShowSharedLim.Text = privdr.GetInt32(1).ToString();
                                LblPrivShowTradLim.Text = privdr.GetInt32(2).ToString();
                                LblPrivShowTradAtt.Text = privdr.GetInt32(3).ToString();
                                LblPrivShowTradSir.Text = privdr.GetInt32(4).ToString();
                                LblPrivShowTradPrem.Text = privdr.GetInt32(5).ToString();
                                LblPrivShowEplLim.Text = privdr.GetInt32(6).ToString();
                                LblPrivShowEplSir.Text = privdr.GetInt32(7).ToString();
                                LblPrivShowEplAtt.Text = privdr.GetInt32(8).ToString();
                                LblPrivShowEplPrem.Text = privdr.GetInt32(9).ToString();
                                LblPrivShowEplWage.Text = privdr.GetInt32(10).ToString();
                                LblPrivShowEplSublim.Text = privdr.GetInt32(11).ToString();
                                LblPrivShowFidLim.Text = privdr.GetInt32(12).ToString();
                                LblPrivShowFidSir.Text = privdr.GetInt32(13).ToString();
                                LblPrivShowFidAtt.Text = privdr.GetInt32(14).ToString();
                                LblPrivShowFidPrem.Text = privdr.GetInt32(15).ToString();
                                LblPrivShowFidSublim.Text = privdr.GetInt32(16).ToString();
                                privdr.Close();
                            }
                            break;
                        case 7:
                            PanelPubShow.Visible = true;
                            using (SqlCommand pubcmd = new SqlCommand(pub, editConn))
                            {
                                SqlDataReader pubdr = pubcmd.ExecuteReader();
                                pubdr.Read();
                                LblPubShowMark.Text = pubdr.GetInt32(0).ToString();
                                LblPubShowTick.Text = pubdr.GetInt32(1).ToString();
                                LblPubShowTrad.Text = pubdr.GetInt32(2).ToString();
                                LblPubShowDic.Text = pubdr.GetInt32(3).ToString();
                                LblPubShowLim.Text = pubdr.GetInt32(4).ToString();
                                LblPubShowSecSir.Text = pubdr.GetInt32(5).ToString();
                                LblPubShowAllSir.Text = pubdr.GetInt32(6).ToString();
                                LblPubShowPrem.Text = pubdr.GetInt32(7).ToString();
                                LblPubShowPrimEx.Text = pubdr.GetInt32(8).ToString();
                                LblPubShowAtt.Text = pubdr.GetInt32(9).ToString();
                                LblPubShowSublim.Text = pubdr.GetInt32(10).ToString();
                                pubdr.Close();
                            }
                            break;
                        default:
                            break;
                    }
                }
                dr.Close();`

Answer 1

加载到一个DataTable.

SqlDataReader pubdr = pubcmd.ExecuteReader();
DataTable dt = new DataTable();
dt.Load(pubdr);

要扩展评论:

foreach (DataRow dr in dt.Rows)
{
    LblEplShowEntity.Text = dr["FIELDNAME"].ToString();
    //...
}