如何使用数据表从SQL表中获取数据

本文介绍了如何使用数据表从SQL表中获取数据的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我现在正在使用数据阅读器，但我需要在下面的方法中使用Datatable。请告诉我如何使用数据表而不是使用数据阅读器来实现以下方法。 我尝试过的方法： 尝试 { con.Open（） ; cmd.CommandText = SELECT c.UHFID，c.EmployeeName，c.EmpRank，c.EmpUnit， c.EmpPNo，c.EmpAdhaarNo，c.EmpDOI，c.EmpValidity，c.EmpPhoto，c.VehicleType，c.VehicleModelNo，c.VehicleNo，c.VehicleOwner，c.VehiclePhoto，c.VisitorsName，c.VisitorType，c。 VisitorsValidity，c.VisitorsVehicle，c.VisitorsAddress，c.VisitorsPhotoIdentity，c.VisitorsPhotoIdentityNo，c.VisitorsPhoto，c.Remarks，c.SemiVisitorName，c.SemiVisitorType，c.SemiVisitorValidity，c.SemiVisitorVehicle，c.SemiVisitorAddress，c.SemiVisitorEmployedLocation， SemiVisitorPhoto FROM RegistrationDetails c内部联接Category.Caster on c.Category = p.Id其中UHFID =' + textBox1.Text + '; cmd.Connection = con; rdr = cmd.ExecuteReader（）; while （rdr.Read（）） { if （rdr [ UHFID]。ToString（）== textBox1 .Text） { // for employye if （rdr [ EmployeeName]。ToString （）！= ） { lbl_empname.Text = rdr [ EmployeeName]。ToString（）; lbl_rank.Text = rdr [ EmpRank]。ToString（）; lbl_unit.Text = rdr [ EmpUnit]。ToString（）; lbl_pno.Text = rdr [ EmpPNo]。ToString（）; lbl_adhar.Text = rdr [ EmpAdhaarNo]。ToString（）; DOI = rdr [ EmpDOI]。ToString（）; lbl_DOI.Text = DOI.Substring（ 0 ， 10 ）; empvalidity = rdr [ EmpValidity]。ToString（）; lbl_validity.Text = empvalidity.Substring（ 0 ， 10 ）; byte [] bytes =（ byte []）rdr [ EmpPhoto]; MemoryStream ms = new MemoryStream（字节）; pb_employee.Image = Image.FromStream（ms）; panel_emp.Location = new 点（ 15 ， 36 ）; panel_emp.Size = new 大小（ 1878 ， 856 ）; panel_semivisitor.Visible = false ; panel_vehicle.Visible = false ; panel_visitor.Visible = false ; panel_emp.Visible = true ; } // 访客 else if （rdr [ VisitorsName]。ToString（）！= && rdr [ 备注]。ToString（）！= ） { lbl_visitorname.Text = rdr [ VisitorsName]。ToString（）; lbl_visitortype.Text = rdr [ VisitorsType]。ToString（）; validityvisitor = rdr [ VisitorsValidity]。ToString（）; lbl_visitorvalidity.Text = validityvisitor.Substring（ 0 ， 10 ）; lbl_visitorehicle.Text = rdr [ VisitorsVehicle]。ToString（） ; lbl_tomeet.Text = rdr [ 备注]。ToString（）; lbl_photoidproof.Text = rdr [ VisitorsPhotoIdentity]]。ToString（）; lbl_idproofdetails.Text = rdr [ VisitorsPhotoIdentityNo]。ToString（）; byte [] bytes =（ byte []）rdr [ VisitorsPhoto]; MemoryStream ms = new MemoryStream（字节）; pb_visitor.Image = Image.FromStream（ms）; panel_visitor.Location = new 点（ 15 ， 36 ）; panel_visitor.Size = new 大小（ 1878 ， 856 ）; panel_visitor.Visible = true ; panel_semivisitor.Visible = false ; panel_emp.Visible = false ; panel_vehicle.Visible = false ; } // 车辆 else if （rdr [ VehicleType]。ToString（）！= ） { lbl_vehicletype.Text = rdr [ VehicleType]的ToString（）; lbl_vehichlemake.Text = rdr [ VehicleModelNo]。ToString（）; lbl_vehicleno.Text = rdr [ VehicleNo]。ToString（）; lbl_vehicleowner.Text = rdr [ VehicleOwner]。ToString（）; byte [] bytes =（ byte []）rdr [ VehiclePhoto]; MemoryStream ms = new MemoryStream（字节）; pb_vehicle.Image = Image.FromStream（ms）; panel_vehicle.Location = new 点（ 15 ， 36 ）; panel_vehicle.Size = new 大小（ 1878 ， 856 ）; panel_vehicle.Visible = true ; panel_visitor.Visible = false ; panel_semivisitor.Visible = false ; panel_emp.Visible = false ; } // for semivisitor else if （rdr [ SemiVisitorName]。ToString（）！= && rdr [ address]。ToString（）！= ） { lbl_seminame.Text = rdr [ SemiVisitorName]。ToString（）; lbl_semitype.Text = rdr [ SemiVisitorType]。ToString（）; validitysemivisitor = rdr [ SemiVisitorValidity]。ToString（）; lbl_semivalidity.Text = validitysemivisitor.Substring（ 0 ， 10 ）; lbl_semvehicle.Text = rdr [ SemiVisitorVehicle]。ToString（）; lbl_semiaddress.Text = rdr [ SemiVisitorAddress]。ToString（）; lbl_semilocation.Text = rdr [ SemiVisitorEmployedLocation]。ToString（）; byte [] bytes =（ byte []）rdr [ SemiVisitorPhoto]; MemoryStream ms = new MemoryStream（字节）; pb_semivisitor.Image = Image.FromStream（ms）; panel_semivisitor.Location = new 点（ 15 ， 36 ）; panel_semivisitor.Size = new 大小（ 1878 ， 856 ）; panel_semivisitor.Visible = true ; panel_emp.Visible = false ; panel_vehicle.Visible = false ; panel_visitor.Visible = false ; } } } con.Close（）; con.Open（）; ds = new DataSet（）; da = new SqlDataAdapter（ select *来自registrationdetails，con）; da.Fill（ds， registrationdetails）; con.Close（）; } catch （例外情况） { MessageBox.Show（ 无法读取UHF TAG， Ecartes-TAG READER，MessageBoxButtons.OK，MessageBoxIcon.Warning）; } 解决方案 I am using data reader right now, but I need to use Datatable in below method. Please let me know how can I implement below method using data table instead of using data reader.What I have tried:try{con.Open(); cmd.CommandText = "SELECT c.UHFID,c.EmployeeName,c.EmpRank, c.EmpUnit , c.EmpPNo , c.EmpAdhaarNo , c.EmpDOI , c.EmpValidity , c.EmpPhoto,c.VehicleType,c.VehicleModelNo,c.VehicleNo,c.VehicleOwner,c.VehiclePhoto,c.VisitorsName,c.VisitorType,c.VisitorsValidity,c.VisitorsVehicle,c.VisitorsAddress,c.VisitorsPhotoIdentity,c.VisitorsPhotoIdentityNo,c.VisitorsPhoto,c.Remarks,c.SemiVisitorName,c.SemiVisitorType,c.SemiVisitorValidity,c.SemiVisitorVehicle,c.SemiVisitorAddress,c.SemiVisitorEmployedLocation,SemiVisitorPhoto FROM RegistrationDetails c inner join CategoryMaster p on c.Category=p.Id where UHFID ='" + textBox1.Text + "'"; cmd.Connection = con; rdr = cmd.ExecuteReader(); while (rdr.Read()) { if (rdr["UHFID"].ToString() == textBox1.Text) { //for employye if (rdr["EmployeeName"].ToString() != "") { lbl_empname.Text = rdr["EmployeeName"].ToString(); lbl_rank.Text = rdr["EmpRank"].ToString(); lbl_unit.Text = rdr["EmpUnit"].ToString(); lbl_pno.Text = rdr["EmpPNo"].ToString(); lbl_adhar.Text = rdr["EmpAdhaarNo"].ToString(); DOI = rdr["EmpDOI"].ToString(); lbl_DOI.Text = DOI.Substring(0, 10); empvalidity = rdr["EmpValidity"].ToString(); lbl_validity.Text = empvalidity.Substring(0, 10); byte[] bytes = (byte[])rdr["EmpPhoto"]; MemoryStream ms = new MemoryStream(bytes); pb_employee.Image = Image.FromStream(ms); panel_emp.Location = new Point(15, 36); panel_emp.Size = new Size(1878, 856); panel_semivisitor.Visible = false; panel_vehicle.Visible = false; panel_visitor.Visible = false; panel_emp.Visible = true; } //for visitor else if (rdr["VisitorsName"].ToString() != "" && rdr["Remarks"].ToString() != "") { lbl_visitorname.Text = rdr["VisitorsName"].ToString(); lbl_visitortype.Text = rdr["VisitorsType"].ToString(); validityvisitor = rdr["VisitorsValidity"].ToString(); lbl_visitorvalidity.Text = validityvisitor.Substring(0, 10); lbl_visitorehicle.Text = rdr["VisitorsVehicle"].ToString(); lbl_tomeet.Text = rdr["Remarks"].ToString(); lbl_photoidproof.Text = rdr["VisitorsPhotoIdentity]"].ToString(); lbl_idproofdetails.Text = rdr["VisitorsPhotoIdentityNo"].ToString(); byte[] bytes = (byte[])rdr["VisitorsPhoto"]; MemoryStream ms = new MemoryStream(bytes); pb_visitor.Image = Image.FromStream(ms); panel_visitor.Location = new Point(15, 36); panel_visitor.Size = new Size(1878, 856); panel_visitor.Visible = true; panel_semivisitor.Visible = false; panel_emp.Visible = false; panel_vehicle.Visible = false; } //for vehicle else if (rdr["VehicleType"].ToString() != "") { lbl_vehicletype.Text = rdr["VehicleType"].ToString(); lbl_vehichlemake.Text = rdr["VehicleModelNo"].ToString(); lbl_vehicleno.Text = rdr["VehicleNo"].ToString(); lbl_vehicleowner.Text = rdr["VehicleOwner"].ToString(); byte[] bytes = (byte[])rdr["VehiclePhoto"]; MemoryStream ms = new MemoryStream(bytes); pb_vehicle.Image = Image.FromStream(ms); panel_vehicle.Location = new Point(15, 36); panel_vehicle.Size = new Size(1878, 856); panel_vehicle.Visible = true; panel_visitor.Visible = false; panel_semivisitor.Visible = false; panel_emp.Visible = false; } //for semivisitor else if (rdr["SemiVisitorName"].ToString() != "" && rdr["address"].ToString() != "") { lbl_seminame.Text = rdr["SemiVisitorName"].ToString(); lbl_semitype.Text = rdr["SemiVisitorType"].ToString(); validitysemivisitor = rdr["SemiVisitorValidity"].ToString(); lbl_semivalidity.Text = validitysemivisitor.Substring(0, 10); lbl_semvehicle.Text = rdr["SemiVisitorVehicle"].ToString(); lbl_semiaddress.Text = rdr["SemiVisitorAddress"].ToString(); lbl_semilocation.Text = rdr["SemiVisitorEmployedLocation"].ToString(); byte[] bytes = (byte[])rdr["SemiVisitorPhoto"]; MemoryStream ms = new MemoryStream(bytes); pb_semivisitor.Image = Image.FromStream(ms); panel_semivisitor.Location = new Point(15, 36); panel_semivisitor.Size = new Size(1878, 856); panel_semivisitor.Visible = true; panel_emp.Visible = false; panel_vehicle.Visible = false; panel_visitor.Visible = false; } } } con.Close(); con.Open(); ds = new DataSet(); da = new SqlDataAdapter("select * from registrationdetails", con); da.Fill(ds, "registrationdetails"); con.Close(); } catch (Exception ex) { MessageBox.Show("Unable to Read the UHF TAG", "Ecartes-TAG READER", MessageBoxButtons.OK, MessageBoxIcon.Warning); } 解决方案 这篇关于如何使用数据表从SQL表中获取数据的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！