VB.net DetailsView使用多个数据源？

Question

我有一个看起来完美的DetailsView。唯一的问题是，有一个字段实际上从另一个表中获取信息。它是一个ID字段，链接到数据库中的另一个表，我希望有一些方法可以让DetailsView中的一个字段从另一个表中提取信息。

有没有办法可以在PicklistID旁边添加+（加号），然后让它显示其他查询的结果？ （选择文本FROM PICKLIST WHERE PicklistID = @PicklistID ???）

UPDATE 12年1月11日：表中的PICKLISTPICKLISTID不是唯一的或主键，所以我不能从SURVEY表引用它。有没有办法给这两列建立关系，以便我可以将我的DetailsView中的SELECT声明更改为包含PICKLISTID？

更新1/23/12：我仍然坚持这一点。我没有得到如何完成这项工作。帮助将不胜感激。我仍然是新的....

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server"> 
</asp:Content> 
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server"> 
<asp:Label ID="Label2" runat="server" Text="<h3>Manage Questions</h3>"></asp:Label> 
<table style="width: 100%"> 
<tr> 
<td align="right"> 
<asp:Label ID="Label1" runat="server" Text="Select Survey:"></asp:Label> 
</td> 
<td> 
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" 
    DataSourceID="dsSurvey" DataTextField="SurveyName" DataValueField="SurveyID"> 
</asp:DropDownList> 
</td> 
</tr> 
<tr> 
<td colspan="2"> 
<asp:DetailsView ID="dvSurveyQuestions" runat="server" AllowPaging="True" 
AutoGenerateRows="False" CellPadding="4" DataKeyNames="QuestionID" 
DataSourceID="dsSurveyQuestions" ForeColor="#333333" GridLines="None" 
Height="50px" Width="100%"> 
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" /> 
<CommandRowStyle BackColor="#E2DED6" Font-Bold="True" /> 
<EditRowStyle BackColor="#999999" /> 
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" /> 
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" /> 
<Fields> 
    <asp:BoundField DataField="QuestionID" HeaderText="QuestionID" 
    InsertVisible="False" ReadOnly="True" SortExpression="QuestionID" /> 
    <asp:TemplateField HeaderText="Question" SortExpression="Question"> 
     <EditItemTemplate> 
      <asp:TextBox ID="TextBox1" runat="server" TextMode="MultiLine" 
      Text='<%# Bind("Question") %>'></asp:TextBox> 
     </EditItemTemplate> 
     <InsertItemTemplate> 
      <asp:TextBox ID="TextBox1" runat="server" TextMode="MultiLine" 
      Text='<%# Bind("Question") %>'></asp:TextBox> 
     </InsertItemTemplate> 
     <ItemTemplate> 
      <asp:Label ID="lblQuestion" runat="server" Text='<%# Bind("Question") %>'> 
      </asp:Label> 
     </ItemTemplate> 
    </asp:TemplateField> 

    <asp:TemplateField HeaderText="Answer Type" SortExpression="AnswerType"> 
     <EditItemTemplate> 
      <asp:DropDownList ID="DropDownList2" runat="server" 
       SelectedValue='<%# Bind("AnswerType") %>'> 
       <asp:ListItem Value="S">Single Choice (radio button)</asp:ListItem> 
       <asp:ListItem Value="M">Multiple Choices (checkboxes)</asp:ListItem> 
       <asp:ListItem Value="T">Text (textbox)</asp:ListItem> 
      </asp:DropDownList> 
     </EditItemTemplate> 
     <InsertItemTemplate> 
      <asp:DropDownList ID="DropDownList3" runat="server" 
       SelectedValue='<%# Bind("AnswerType") %>'> 
       <asp:ListItem Value="S">Single Choice (radio button)</asp:ListItem> 
       <asp:ListItem Value="M">Multiple Choices (checkboxes)</asp:ListItem> 
       <asp:ListItem Value="T">Text (textbox)</asp:ListItem> 
      </asp:DropDownList> 
     </InsertItemTemplate> 
     <ItemTemplate> 
      <asp:Label ID="lblAnswerType" runat="server" 
      Text='<%# Bind("AnswerType") %>'></asp:Label> 
     </ItemTemplate> 
    </asp:TemplateField> 

    <asp:TemplateField HeaderText="Question Type" SortExpression="QType"> 
     <EditItemTemplate> 
      <asp:DropDownList ID="DropDownList4" runat="server" 
       SelectedValue='<%# Bind("QType") %>'> 
       <asp:ListItem Value="Picklist">Picklist</asp:ListItem> 
       <asp:ListItem Value="Text">Text</asp:ListItem> 
      </asp:DropDownList> 
     </EditItemTemplate> 
     <InsertItemTemplate> 
      <asp:DropDownList ID="DropDownList5" runat="server" 
       SelectedValue='<%# Bind("QType") %>'> 
       <asp:ListItem Value="Picklist">Picklist</asp:ListItem> 
       <asp:ListItem Value="Text">Text</asp:ListItem> 
      </asp:DropDownList> 
     </InsertItemTemplate> 
     <ItemTemplate> 
      <asp:Label ID="lblQType" runat="server" Text='<%# Bind("QType") %>'> 
      </asp:Label> 
     </ItemTemplate> 
    </asp:TemplateField> 

    <asp:TemplateField HeaderText="Answer" SortExpression="TEXT"> 
     <EditItemTemplate> 

     </EditItemTemplate> 
     <InsertItemTemplate> 

     </InsertItemTemplate> 
     <ItemTemplate> 
      <asp:HiddenField ID="HiddenField1" runat="server" Value='<%# Bind("PicklistID") %>' /> 
      <asp:SqlDataSource ID="dsPicklist" runat="server" 
    ConnectionString="<%$ ConnectionStrings:SurveyConnectionString %>" 
    SelectCommand="SELECT DISTINCT p.TEXT, p.PICKLISTID 
        FROM PICKLIST p JOIN C_Survey_Questions c 
        ON c.PicklistID = p.PICKLISTID 
        AND c.SurveyID = @SurveyID 
        ORDER BY p.TEXT"> 
       <SelectParameters> 
        <asp:ControlParameter ControlID="HiddenField1" Name="PicklistID" 
      PropertyName="SelectedValue" Type="String" /> 

       </SelectParameters> 
      </asp:SqlDataSource> 
      <asp:Label ID="lblTEXT" runat="server" Text=""></asp:Label> 
     </ItemTemplate> 
    </asp:TemplateField> 

    <asp:BoundField DataField="QuestionNum" HeaderText="Question Number" 
     SortExpression="QuestionNum" /> 
    <asp:BoundField DataField="Subsequence" HeaderText="Subsequence" 
     SortExpression="Subsequence" /> 
    <asp:CheckBoxField DataField="Active" HeaderText="Active" 
      SortExpression="Active" /> 

    <asp:BoundField DataField="Script" HeaderText="Script" 
     SortExpression="Script" /> 

    <asp:CheckBoxField DataField="Question_Locked" HeaderText="Question Locked" 
      SortExpression="Question_Locked" /> 

    <asp:BoundField DataField="QHelp" HeaderText="Question Help" 
     SortExpression="QHelp" /> 
    <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" 
     ShowInsertButton="True" /> 
    </Fields> 
<FieldHeaderStyle BackColor="#E9ECF1" Font-Bold="True" Width="10%" /> 
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" /> 
<AlternatingRowStyle BackColor="White" ForeColor="#284775" /> 
</asp:DetailsView> 
</td> 
</tr> 
</table> 

<asp:SqlDataSource ID="dsSurvey" runat="server" 
    ConnectionString="<%$ ConnectionStrings:SurveyConnectionString %>" 
    SelectCommand="SELECT [SurveyID], [SurveyName] 
        FROM [C_Survey] 
        ORDER BY [SurveyName]"> 
</asp:SqlDataSource> 

<asp:SqlDataSource ID="dsSurveyQuestions" runat="server" 
    ConnectionString="<%$ ConnectionStrings:SurveyConnectionString %>" 
    DeleteCommand="DELETE FROM [C_Survey_Questions] WHERE [QuestionID] = @QuestionID" 
    InsertCommand="INSERT INTO [C_Survey_Questions] ([SurveyID], [Question], [QType], 
        [PickListID], [QuestionNum], [Subsequence], [Active], [Script], 
        [Question_Locked], [QHelp], [Createdate], 
        [Modifydate], [AnswerType]) 
        VALUES (@SurveyID, @Question, @QType, @PickListID, @QuestionNum, 
        @Subsequence, @Active, @Script, @Question_Locked, @QHelp, 
        getdate(), getdate(), @AnswerType)" 
    SelectCommand="SELECT * FROM [C_Survey_Questions] 
        WHERE ([SurveyID] = @SurveyID)" 
    UpdateCommand="UPDATE [C_Survey_Questions] SET [SurveyID] = @SurveyID, 
        [Question] = @Question, [QType] = @QType, 
        [PickListID] = @PickListID, [QuestionNum] = @QuestionNum, 
        [Subsequence] = @Subsequence, [Active] = @Active, 
        [Script] = @Script, [Question_Locked] = @Question_Locked, 
        [QHelp] = @QHelp, [Modifydate] = getdate(), 
        [AnswerType] = @AnswerType 
        WHERE [QuestionID] = @QuestionID"> 
    <DeleteParameters> 
     <asp:Parameter Name="QuestionID" Type="Int32" /> 
    </DeleteParameters> 
    <InsertParameters> 
     <asp:Parameter Name="SurveyID" Type="Int32" /> 
     <asp:Parameter Name="Question" Type="String" /> 
     <asp:Parameter Name="QType" Type="String" /> 
     <asp:Parameter Name="PickListID" Type="String" /> 
     <asp:Parameter Name="QuestionNum" Type="Int32" /> 
     <asp:Parameter Name="Subsequence" Type="Int32" /> 
     <asp:Parameter Name="Active" Type="Boolean" /> 
     <asp:Parameter Name="Script" Type="String" /> 
     <asp:Parameter Name="Question_Locked" Type="Boolean" /> 
     <asp:Parameter Name="QHelp" Type="String" /> 
     <asp:Parameter Name="Createdate" Type="DateTime" /> 
     <asp:Parameter Name="Modifydate" Type="DateTime" /> 
     <asp:Parameter Name="AnswerType" Type="String" /> 
    </InsertParameters> 
    <SelectParameters> 
     <asp:ControlParameter ControlID="DropDownList1" Name="SurveyID" 
      PropertyName="SelectedValue" Type="Int32" /> 
    </SelectParameters> 
    <UpdateParameters> 
     <asp:Parameter Name="SurveyID" Type="Int32" /> 
     <asp:Parameter Name="Question" Type="String" /> 
     <asp:Parameter Name="QType" Type="String" /> 
     <asp:Parameter Name="PickListID" Type="String" /> 
     <asp:Parameter Name="QuestionNum" Type="Int32" /> 
     <asp:Parameter Name="Subsequence" Type="Int32" /> 
     <asp:Parameter Name="Active" Type="Boolean" /> 
     <asp:Parameter Name="Script" Type="String" /> 
     <asp:Parameter Name="Question_Locked" Type="Boolean" /> 
     <asp:Parameter Name="QHelp" Type="String" /> 
     <asp:Parameter Name="Modifydate" Type="DateTime" /> 
     <asp:Parameter Name="AnswerType" Type="String" /> 
     <asp:Parameter Name="QuestionID" Type="Int32" /> 
    </UpdateParameters> 
</asp:SqlDataSource> 
</asp:Content> 



Partial Class Admin_ManageQuestions 
Inherits System.Web.UI.Page 
Protected Sub dsPicklist_ItemSelecting(ByVal sender As Object, ByVal e As 
System.EventArgs) Handles Me.Load 
    Dim myControl1 As Control = FindControl("lblTEXT") 
    If (Not myControl1 Is Nothing) Then 
     myControl1.DataBind() 
    Else 
     'Control not found 
    End If 
End Sub 
Protected Sub dvSurveyQuestions_ItemInserting(ByVal sender As Object, ByVal e As 
System.Web.UI.WebControls.DetailsViewInsertEventArgs) Handles 
dvSurveyQuestions.ItemInserting 
    'The DetailsView does not include SurveyID column...we need to set this column 
    during INSERT operations because each question must belong to some survey. 
    e.Values("SurveyID") = DropDownList1.SelectedValue 
End Sub 
Protected Sub dvSurveyQuestions_ItemUpdating(ByVal sender As Object, ByVal e As 
System.Web.UI.WebControls.DetailsViewUpdateEventArgs) Handles 
dvSurveyQuestions.ItemUpdating 
    'The DetailsView does not include SurveyID column...we need to set this column 
    during UPDATE operations because each question must belong to some survey. 
    e.NewValues("SurveyID") = DropDownList1.SelectedValue 
End Sub 
Protected Sub dvSurveyQuestions_DataBound(ByVal sender As Object, ByVal e As 
System.EventArgs) Handles dvSurveyQuestions.DataBound 
    'The event handler checks the row count of the DetailsView control. 
    If it is zero then the mode of the DetailsView is changed to Insert using 
    ChangeMode() method. 
    If dvSurveyQuestions.Rows.Count = 0 Then 
     dvSurveyQuestions.ChangeMode(DetailsViewMode.Insert) 
    End If 
End Sub 
End Class 

Answer 1

你可以这样做，但可能不符合你想要的方式。

最简单的方法是在DetailsView本身上使用DataBinding事件。然后使用代码来运行查询。

另一种方法是创建自己的控件作为subclass of BoundField和覆盖OnDataBindField方法

最高效的方法是在一个数据视图或其他结构的源加入数据。理想情况下，数据的加入应尽可能接近数据的实际来源（例如在SQL查询或视图中），以避免不必要的网络到数据库的旅行。对于单行来说，这不是一个大问题，但这通常是你应该做的。