WebLog of Ken Cox

I count on IntelliSense a lot when programming - especially in C# which (arrggh!) is case-sensitive. However, I just had a case where IntelliSense led me to make a mistake that cost me half an hour.

I was happily working in LINQ and had the following code:

protected void LinqDataSource1_Deleting
    (object sender, LinqDataSourceDeleteEventArgs e)
{
    NWDataClassesDataContext dc = new NWDataClassesDataContext();
    Product prod;
    prod = (Product)e.OriginalObject;
    var q = from o in dc.Order_Details
            where o.ProductID == prod.ProductID
            select o;
    foreach (Order_Detail od in q)
    {
        dc.Order_Details.DeleteAllOnSubmit(od); // fails!
    }
    dc.SubmitChanges();
}

There was an error in the foreach loop:

The type arguments for method 'System.Data.Linq.Table<Order_Detail>.DeleteAllOnSubmit<TSubEntity>(System.Collections.Generic.IEnumerable<TSubEntity>)' cannot be inferred from the usage. Try specifying the type arguments explicitly.  

After going in circles (and unsuccessfully searching the error message), I finally understood what the error was telling me: I had blithely accepted the DeleteAllOnSubmit() method which came first in the alphabetical list of members. The method that I really wanted was the next item in the IntelliSense listbox, DeleteOnSubmit() as shown here:

protected void LinqDataSource1_Deleting
    (object sender, LinqDataSourceDeleteEventArgs e)
{
    NWDataClassesDataContext dc = new NWDataClassesDataContext();
    Product prod;
    prod = (Product)e.OriginalObject;
    var q = from o in dc.Order_Details
            where o.ProductID == prod.ProductID
            select o;
    foreach (Order_Detail od in q)
    {
        dc.Order_Details.DeleteOnSubmit(od);
    }
    dc.SubmitChanges();
}

I probably wouldn't have goofed up if forced to type the method name rather than hitting Tab to select something from IntelliSense.

Hmmm. Perhaps I shouldn't admit that I lose time on silly mistakes like this?  Oh well. My hope is that someone else will find this blog entry while searching the error message and profit from my inattention.