Question

I know LINQ doesn’t have the SQL IN clause but rather uses “contains”. Can I use this on a LinqDataSource? I want to write a simple query that is equivelent to this:
SELECT * FROM tableA
WHERE tableA.requestType NOT IN (5,6,7,8) AND
tableA.someBitField IS NULL.

Is this possible using the LinqDataSource out of the box?
Thanks for any pointers.

Cheers,
~ck in San Diego

Answer 1

Yes, quite possible. Just handle the Selecting event on the datasource. The LinqDataSoruce class page on MSDN contains a great example already. Modifying that:

public partial class Default3 : System.Web.UI.Page
{
    int[] validRequestTypes = { 5, 6, 7, 8 };

    protected void Page_Load(object sender, EventArgs e)
    {
    }

    protected void LinqDataSource_Selecting(object sender, LinqDataSourceSelectEventArgs e)
    {
        using(var dc = new MyDataContext())
        {
            var qry = from item in dc.tableAs 
                      where validRequestTypes.contains(item.requestType)
                         && item.someBitField == null
                      select item;
            e.Result = qry;
        }
    }
}