Question

我正在发现这一错误。

You tried to assign the Null value to a variable that is not a Variant data type.

This is the code:

</asp:GridView>
    <asp:AccessDataSource ID="AccessDataSource1" runat="server" 
        DataFile="~/videogames.accdb" 
        DeleteCommand="DELETE FROM [Table1] WHERE [ID] = ?" 
        InsertCommand="INSERT INTO [Table1] ( ID,Name, ScreenName, Age, Game, YearsPlaying) VALUES (?, ?, ?, ?, ?, ?)" 
        SelectCommand="SELECT * FROM [Table1]" 
        UpdateCommand="UPDATE [Table1] SET [Name] = ?, [ScreenName] = ?, [Age] = ?, [Game] = ?, [YearsPlaying] = ? WHERE [ID] = ?">
        <DeleteParameters>
            <asp:Parameter Name="ID" Type="Int32" />
        </DeleteParameters>
        <InsertParameters>
            <asp:Parameter Name="ID" Type="Int32" />
            <asp:Parameter Name="Name" Type="String" />
            <asp:Parameter Name="ScreenName" Type="String" />
            <asp:Parameter Name="Age" Type="Int32" />
            <asp:Parameter Name="Game" Type="String" />
            <asp:Parameter Name="YearsPlaying" Type="String" />
        </InsertParameters>
        <UpdateParameters>
            <asp:Parameter Name="Name" Type="String" />
            <asp:Parameter Name="ScreenName" Type="String" />
            <asp:Parameter Name="Age" Type="Int32" />
            <asp:Parameter Name="Game" Type="String" />
            <asp:Parameter Name="YearsPlaying" Type="String" />
            <asp:Parameter Name="ID" Type="Int32" />
        </UpdateParameters>

我已经结束,我不能让它工作。谁能帮助我? 感谢。

当我试图删除“Id”中的“参数”时,它有不同的错误。

Answer 1

Remove the IDInsertPara amount:

<asp:Parameter Name="ID" Type="Int32" />

更改<代码>InsertCommand:

InsertCommand="INSERT INTO [Table1] (Name, ScreenName, Age, Game, YearsPlaying) VALUES (?, ?, ?, ?,?)"

解决“你试图将Null值分配给一个并非变式数据类型的变量”。例外情况

Answer 2

It might be because in the insert you have the ID while it could be an Autonumeric in the database. Try removing it from the Insert Command. Good luck!

友情链接