We’ve been working with DbLinq for a while now, at HexaSystems and recently using it together with Dynamic Linq and SQLite I programed a call to the Count method of a Queryable object as follows:

 1public static int Count(this IQueryable source)
 3    if (source == null) throw new ArgumentNullException("source");
 5    return (int)source.Provider.Execute(
 6        Expression.Call(
 7            typeof(Queryable), 
 8            "Count",
 9            new Type[] { source.ElementType },
10            source.Expression));

I noticed that when doing so against a DbLInq Table object the following method is called:

1public object Execute(Expression expression)
3    .... 

The problem is that the function calls the generic Execute method inside the same class with the generic argument of type object: “Execute(expression)” which causes an invalid cast exception in the case I’m talking about, and potentially any call to this method could fail when the expression evaluation creates a generic type. I’ve submitted a patch to DBLinq developers and it was offically accepted: http://code.google.com/p/dblinq2007/source/detail?r=1224