Question

我现在已经搜索了两天，无法想出这个。我是使用Razor的新手。无论我尝试什么，我都会收到以下错误。基本上我试图从数据库中提取数据并渲染图表（工作）。然后我还想要一个下拉菜单，以便用户可以选择要查看的特定点并让它呈现新图表这是最重要的代码：

    @{  var db = Database.Open("telecommConnectionString"); 
     var data = db.Query("select distinct employees.cost_center, costcenters.costcenterdesc from    dbo.invoices, dbo.employees, dbo.costcenters where invoices.emp_id = employees.emp_id and employees.supervisor = '11111111' and employees.cost_center = costcenters.costcenterid group by costcenterdesc,cost_center, bill_date");

var categories = data.Select(categorieslist =>new SelectListItem {
     Value = categorieslist.cost_center.ToString(),
     Text = categorieslist.costcenterdesc
 });
var filename="~MCCE2.jpg";
var cat = "";   
  if(!IsPost){

var dbdata = db.Query("select a.bill_date, a.costcenterdesc, a.total from (select invoices.bill_date, sum(invoices.total_current) as total, costcenters.costcenterdesc from dbo.invoices, dbo.employees, dbo.costcenters where invoices.emp_id = employees.emp_id and employees.supervisor = '11111111' and employees.cost_center = costcenters.costcenterid group by costcenterdesc, bill_date)a"); 

 var myChart = new Chart(width: 800, height: 500, theme: ChartTheme.Blue) 
.AddTitle("Count of Employees by Carrier") 
.AddLegend()
.DataBindCrossTable(dbdata, groupByField:"costcenterdesc", xField:"bill_date", yFields:"total")
.Save(filename);

 }

 if(IsPost){

     cat=Request.Form["costcenter"];
 var dbdata =  db.Query("select invoices.bill_date, sum(invoices.total_current) as total, costcenters.costcenterdesc from dbo.invoices, dbo.employees, dbo.costcenters where invoices.emp_id = employees.emp_id and employees.supervisor = '11111111' and employees.cost_center = costcenters.costcenterid and costcenters.costcenterid = @0 group by costcenterdesc, bill_date"); 

 var myChart = new Chart(width: 800, height: 500, theme: ChartTheme.Yellow) 
.AddTitle("Count of Employees by Carrier") 
.AddLegend()
.DataBindCrossTable(dbdata, groupByField:"costcenterdesc", xField:"bill_date", yFields:"total")
.Save(filename);
 }
 }

这是我的HTML来调用下拉列表和图表：

 <form method="post" action="MCCE2">
        Select Cost Center:
         @Html.DropDownList("costcenter", "--Choose Your Cost Center--", categories )
        <input type="submit" value="Submit">
    </form>

      <p>     
    </br>
    <img src="@Href(filename)" alt="@Href(filename)"/>

无论我尝试什么，这都是我得到的错误：

异常详细信息：

System.Data.SqlClient.SqlException: Must declare the scalar variable "@0".

Line 32:  var dbdata =  db.Query("select invoices.bill_date, sum(invoices.total_current) as total, costcenters.costcenterdesc from dbo.invoices, dbo.employees, dbo.costcenters where invoices.emp_id = employees.emp_id and employees.supervisor = '11111111' and employees.cost_center = costcenters.costcenterid and costcenters.costcenterid = @0 group by costcenterdesc, bill_date");

任何帮助都会很棒。感谢

Answer 1

这是因为你有SQL的WHERE子句：

costcenters.costcenterid = @0

你的意思是，或者你的意思是传入零，或者实际上你是说这是一个你设置的参数（但可能已经忘记了）？

我认为您想要传递所选类别：

cat=Request.Form["costcenter"];

你还没有做过。代码需要更改为：

var dbdata =  db.Query("select invoices.bill_date, sum(invoices.total_current) as total, costcenters.costcenterdesc from dbo.invoices, dbo.employees, dbo.costcenters where invoices.emp_id = employees.emp_id and employees.supervisor = '11111111' and employees.cost_center = costcenters.costcenterid and costcenters.costcenterid = @0 group by costcenterdesc, bill_date", cat);

WebMatrix Razor - 必须声明标量变量“@ 0”

1 个答案: