Multiple possible FilterExpression's on SqlDataSource issue

I have an SqlDataSource in a page, which will display different results depending on 1 or 2 query strings, and/or a filter textbox.

Here is my SqlDataSource and filters:

  <asp:SqlDataSource ID="sdsAudits" runat="server" 
        ConnectionString="<%$ ConnectionStrings:constring %>" 
        SelectCommand="SELECT * FROM [Audit]" FilterExpre开发者_StackOverflow社区ssion="source = {0} AND customer = {1} AND (itemID like '%{2}%' OR parentID like '%{2}%')">
        <FilterParameters>
        <asp:QueryStringParameter Name="source" QueryStringField="source" />
        <asp:QueryStringParameter Name="customer" QueryStringField="customer" />
        <asp:ControlParameter Name="txtFilter" ControlID="txtFilter" PropertyName="Text" />
        </FilterParameters>

But for some reason, the filtering for any of the 3 possible filters don't work. I tried taking out the 2 query string filters, and leaving just the textbox filter, and it worked fine then - so I'm guessing my filter expression is wrong?

Any ideas guys? Remember all 3 filters could be 'active' at once, if they have the 2 query strings and have typed into the textbox, or they could be none at all, or of course anything in between.

Filter is intended to work in DataSet mode - data is retrieved into memory, and then filtered. Not very efficient - much better to use parameters in the select command itself, like so:

<asp:SqlDataSource ID="sdsAudits" runat="server" 
    ConnectionString="<%$ ConnectionStrings:constring %>" 
    SelectCommand="SELECT * FROM [Audit] where source = @source AND customer = @customer AND (itemID like '%' + @txtFilter + '%' OR parentID like '%'+@txtFilter+'%')">
    <SelectParameters>
      <asp:QueryStringParameter Name="source" QueryStringField="source" />
      <asp:QueryStringParameter Name="customer" QueryStringField="customer" />
      <asp:ControlParameter Name="txtFilter" ControlID="txtFilter" PropertyName="Text" />
    </SelectParameters>
</asp:SqlDataSource>

or just add

  DataSourceMode="DataSet"

to your SqlDataSource tag