Question

我有一个ASP.NET页面，它有一个带有复选框控件的gridview，它绑定到一个查询（下面的简化版本）：

<asp:SqlDataSource ID="gvPhonesDataSource" runat="server" OnInserted="gvPhonesDataSource_Inserted"
    ConnectionString="<%$ ConnectionStrings:ConnString %>" 
    SelectCommand="SELECT p.[CustomerPhoneID]
                ,p.[IsActive]
            FROM [dbo].[CustomerPhones] p
            WHERE p.CustomerContactID = @CustomerContactID
            UNION SELECT -1 AS CustomerPhoneID, 0 AS [IsActive]"
    <SelectParameters>
        <asp:ControlParameter Name="CustomerContactID" Type="Int32" ControlID="contactid" PropertyName="Text" />
    </SelectParameters>
</asp:SqlDataSource>

<asp:gridview ID="gvPhones" runat="server" DataSourceID="gvPhonesDataSource"
    AutoGenerateColumns="False" DataKeyNames="CustomerPhoneID" 
    CssClass="searchresultsgrid" ShowFooter="True" OnRowCommand="gvPhones_RowCommand" AllowSorting="True"
    OnRowDataBound="gvPhones_RowDataBound">
    <Columns>
        <asp:BoundField DataField="CustomerPhoneID" InsertVisible="false" ReadOnly="true" Visible="False" />

        <asp:TemplateField HeaderText="Active?" SortExpression="IsActive">
            <FooterTemplate>
                <asp:CheckBox runat="server" Checked='<%# Bind("IsActive") %>' ID="chkPhoneIsActive"></asp:CheckBox>
            </FooterTemplate>
            <EditItemTemplate>
                <asp:CheckBox runat="server" Checked='<%# Bind("IsActive") %>' ID="chkPhoneIsActive"></asp:CheckBox>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label runat="server" Text='<%# Bind("IsActive") %>' ID="lblPhoneIsActive"></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>


        <asp:TemplateField ShowHeader="False">
            <EditItemTemplate>
                <asp:LinkButton runat="server" Text="Update" CommandName="Update" CausesValidation="True" ID="PhoneUpdate"></asp:LinkButton>&nbsp;<asp:LinkButton runat="server" Text="Cancel" CommandName="Cancel" CausesValidation="False" ID="PhoneEditCancel"></asp:LinkButton>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:LinkButton runat="server" Text="Edit" CommandName="Edit" CausesValidation="False" ID="PhoneEdit"></asp:LinkButton>&nbsp;<asp:LinkButton runat="server" Text="Delete" CommandName="Delete" CausesValidation="False" ID="PhoneDelete"></asp:LinkButton>
            </ItemTemplate>
            <FooterTemplate>
                <asp:LinkButton runat="server" Text="Save New Phone" CommandName="FooterInsert" CausesValidation="True" ID="PhoneInsert"></asp:LinkButton>
            </FooterTemplate>
        </asp:TemplateField>
    </Columns>
</asp:gridview>

一切正常，没有SqlDataSource中SelectCommand中的UNION SELECT。但是当我输入UNION SELECT时，gridview的IsActive列中的值将停止列为“是”或“否”，并开始列为“1”或“0”，当我尝试进入编辑时（尝试将IsActive绑定到复选框），我收到以下错误：

Exception Details: System.InvalidCastException: Specified cast is not valid.

Source Error: 

Line 143:                            </FooterTemplate>
Line 144:                            <EditItemTemplate>
Line 145:                                <asp:CheckBox runat="server" Checked='<%# Bind("IsActive") %>' ID="chkPhoneIsActive"></asp:CheckBox>
Line 146:                            </EditItemTemplate>
Line 147:                            <ItemTemplate>

Source File: ...\ContactEdit.aspx    Line: 145

我怀疑问题出现在查询中...... UNION导致绑定的IsActive列以字符串形式返回，而不是布尔值（无论如何，这是编译器认为的）。如何修复UNION以便继续将IsActive视为布尔值？

仅供参考，表格的相关部分（SQL Server 2014）如下：

CREATE TABLE [dbo].[CustomerPhones](
    [CustomerPhoneID] [int] IDENTITY(1,1) NOT NULL,
    [IsActive] [bit] NOT NULL CONSTRAINT [DF_CustomerPhones_IsActive]  DEFAULT ((1)),
 CONSTRAINT [PK_CustomerPhones] PRIMARY KEY CLUSTERED 
(
    [CustomerPhoneID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

非常感谢！

Answer 1

您

0 AS [IsActive]

表示“0作为整数”而不是“0作为位”。

您可以使用CAST：

解决此问题

CAST(0 AS BIT) AS [IsActive]

使用带有布尔值的联合查询并将其设置为复选框asp.net时出错

1 个答案: