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asp.netwebformssqldatasourcequerystringparameter

Question Mark as Query Parameter?

I have stumbled upon a DataSource sample at http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.querystringparameter(v=vs.100).aspx

The code is as follows

<%@Page  Language="C#" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
private void UpdateRecords(Object source, EventArgs e)
{
  // This method is an example of batch updating using a
  // data source control. The method iterates through the rows
  // of the GridView, extracts each CheckBox from the row and, if
  // the CheckBox is checked, updates data by calling the Update
  // method of the data source control, adding required parameters
  // to the UpdateParameters collection.
  CheckBox cb;
  foreach(GridViewRow row in this.GridView1.Rows) {
    cb = (CheckBox) row.Cells[0].Controls[1];
    if(cb.Checked) {
      string oid = (string) row.Cells[1].Text;
      MyAccessDataSource.UpdateParameters.Add(new Parameter("date",TypeCode.DateTime,DateTime.Now.ToString()));
      MyAccessDataSource.UpdateParameters.Add(new Parameter("orderid",TypeCode.String,oid));
      MyAccessDataSource.Update();
      MyAccessDataSource.UpdateParameters.Clear();
    }
  }
}
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">

<!-- Security Note: The SqlDataSource uses a QueryStringParameter,
     Security Note: which does not perform validation of input from the client.
     Security Note: To validate the value of the QueryStringParameter, handle the Selecting event. -->

      <asp:SqlDataSource
        id="MyAccessDataSource"
        runat="server"
        ProviderName="<%$ ConnectionStrings:MyPasswordProtectedAccess.providerName%>"
        ConnectionString="<%$ ConnectionStrings:MyPasswordProtectedAccess%>"
        SelectCommand="SELECT OrderID, OrderDate, RequiredDate, ShippedDate FROM Orders WHERE EmployeeID=?"
        UpdateCommand="UPDATE Orders SET ShippedDate=? WHERE OrderID = ?">
        <SelectParameters>
          <asp:QueryStringParameter Name="empId" QueryStringField="empId" />
        </SelectParameters>
      </asp:SqlDataSource>

      <asp:GridView
        id ="GridView1"
        runat="server"
        DataSourceID="MyAccessDataSource"
        AllowPaging="True"
        PageSize="10"
        AutoGenerateColumns="False">
          <columns>
            <asp:TemplateField HeaderText="">
              <ItemTemplate>
                <asp:CheckBox runat="server" />
              </ItemTemplate>
            </asp:TemplateField>
            <asp:BoundField HeaderText="Order" DataField="OrderID" />
            <asp:BoundField HeaderText="Order Date" DataField="OrderDate" />
            <asp:BoundField HeaderText="Required Date" DataField="RequiredDate" />
            <asp:BoundField HeaderText="Shipped Date" DataField="ShippedDate" />
          </columns>
      </asp:GridView>

      <asp:Button
        id="Button1"
        runat="server"
        Text="Update the Selected Records As Shipped"
        OnClick="UpdateRecords" />

      <asp:Label id="Label1" runat="server" />

    </form>
  </body>
</html>

I have tried this code. But the server returns

Incorrect syntax near '?'. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Data.SqlClient.SqlException: Incorrect syntax near '?'.

What do EmployeeID=?, ShippedDate=? and OrderID = ? specify in SelectCommand and UpdateCommand? Are they properly written?

How to make this code work?

Solution

  • The three parameters should be replaced with

    EmployeeID = @empId
ShippedDate = @date
OrderID = @ordered

    MSDN's samples sometimes don't work.