issue on displaying integer value to zero when DB value is NULL

Question

Hi all I have written the following to display the integer values from database to the gridview column as follows

<asp:TemplateField>
<ItemTemplate>
<asp:Label ID="lblTotalReplies" runat="server" Text='<%#Eval("TotalReplies")==System.DBNull ?  "0" : Convert.ToInt16(Eval("TotalReplies")).ToString() %>'></asp:Label>&nbsp;&nbsp;Replies</li>
</ItemTemplate>
</asp:TemplateField>

But I am getting an error as System.DBNull' is a 'type', which is not valid in the given context can some one help me how can I display 0 when I am having null value in database. I don't want to bind using rowdatabound or some other

Answer 1

Compare with DBNull.Value

<asp:Label ID="lblTotalReplies" runat="server" 
     Text='<%#Eval("TotalReplies") ==System.DBNull.Value ?  "0" : 
           Convert.ToInt16(Eval("TotalReplies")).ToString() %>'>
</asp:Label>&nbsp;&nbsp;Replies</li>

DBNull is the type, while the Value property

Represents the sole instance of the DBNull class.

Answer 2

It's true. It is a type. Maybe you're looking for the static Value field on it?

Eval("TotalReplies")==System.DBNull.Value

Represents the sole instance of the DBNull class.

---

Ravi's comment was pointing out that if your SQL currently looks like this:

SELECT TotalReplies, ...

Then you could change it to:

SELECT ISNULL(TotalReplies,0) as TotalReplies, ...

I'd usually use COALESCE rather than ISNULL , it would look identical in this case.

Answer 3

The System.DBNull type has a static field Value to which you should compare:

<asp:TemplateField>
    <ItemTemplate>
        <asp:Label ID="lblTotalReplies" runat="server" Text='<%#Eval("TotalReplies") == System.DBNull.Value ?  "0" : Convert.ToInt16(Eval("TotalReplies")).ToString() %>'></asp:Label>&nbsp;&nbsp;Replies</li>
    </ItemTemplate>
</asp:TemplateField>