需要帮助将参数传递给ExecuteScalar

本文介绍了需要帮助将参数传递给ExecuteScalar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 29岁程序员，3月因学历无情被辞！ Hello all 我收到一条错误消息：对象引用未设置为对象的实例。行旁边：有人可以帮我修复此错误 var orderExists =（ Int32 ）ChkavailbleJobCMD.ExecuteScalar（）> 0 ; protected void LinkBut​​ton4_Click（ object sender，EventArgs e） { JobsMView.ActiveViewIndex = 2 ; 使用（ var UsOrderCon = new SqlConnection（cs）） { UsOrderCon.Open（）; string chksBervJobsSt = 选择JobNum，Jobtitle，Dept，VacCountry，Employer from Employer = @ Emp; SqlCommand ChkavailbleJobCMD = new SqlCommand（chksBervJobsSt，UsOrderCon）; ChkavailbleJobCMD.Parameters.AddWithValue（ @Emp， Berava）; var orderExists =（ Int32 ）ChkavailbleJobCMD.ExecuteScalar（）> 0 ; if （orderExists） { jobsAvaPan.Visible = 真; SqlDataAdapter BervJonavaADPA = new SqlDataAdapter（ SELECT JobNum，Jobtitle，Dept，VacCountry，Employer FROM jobs WHERE Employer = @Emp，cs）; BervJonavaADPA.SelectCommand.Parameters.AddWithValue（ @Emp， Berava）; DataSet BervJonavaDST = new DataSet（）; BervJonavaADPA.Fill（BervJonavaDST）; GridView1.DataSource = BervJonavaDST.Tables [ 0 ]; GridView1.DataBind（）; } else { NoJobAvPan.Visible = 真; NoJobLbl.Text = 抱歉，我们目前没有任何工作可用; } } } 解决方案 更改 选择 JobNum，Jobtitle，Dept，VacCountry，雇主来自的工作其中雇主= @Emp to 选择 count（*）来自作业其中雇主= @ EMP Hello allI am getting an error message: " Object reference not set to an instance of an object. " next to line: so can someone help me to fix this errorvar orderExists = (Int32)ChkavailbleJobCMD.ExecuteScalar() > 0;protected void LinkButton4_Click(object sender, EventArgs e) { JobsMView.ActiveViewIndex = 2; using (var UsOrderCon = new SqlConnection(cs)) { UsOrderCon.Open(); string chksBervJobsSt = "Select JobNum, Jobtitle, Dept, VacCountry, Employer from jobs where Employer=@Emp"; SqlCommand ChkavailbleJobCMD = new SqlCommand(chksBervJobsSt, UsOrderCon); ChkavailbleJobCMD.Parameters.AddWithValue("@Emp", "Berava"); var orderExists = (Int32)ChkavailbleJobCMD.ExecuteScalar() > 0; if (orderExists) { jobsAvaPan.Visible = true; SqlDataAdapter BervJonavaADPA = new SqlDataAdapter("SELECT JobNum, Jobtitle, Dept, VacCountry, Employer FROM jobs WHERE Employer = @Emp ", cs); BervJonavaADPA.SelectCommand.Parameters.AddWithValue("@Emp", "Berava"); DataSet BervJonavaDST = new DataSet(); BervJonavaADPA.Fill(BervJonavaDST); GridView1.DataSource = BervJonavaDST.Tables[0]; GridView1.DataBind(); } else { NoJobAvPan.Visible = true; NoJobLbl.Text = "Sorry, we don't have any job available at the moment"; } } } 解决方案 changeSelect JobNum, Jobtitle, Dept, VacCountry, Employer from jobs where Employer=@EmptoSelect count(*) from jobs where Employer=@Emp 这篇关于需要帮助将参数传递给ExecuteScalar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！ 上岸，阿里云！