Entity Framework calling MAX on null on Records

Question

When calling Max() on an IQueryable and there are zero records I get the following exception.

The cast to value type \'Int32\' failed because the materialize

Answer 1

I want to suggest a merge from the existing answers:

@divega answer works great and the sql output is fine but because of 'don't repeat yourself' an extension will be a better way like @Code Uniquely showed. But this solution can output more complex sql as you needed. But you can use the following extension to bring both together:

 public static int MaxOrZero(this IQueryable source, 
 Expression> selector)
        {
            var converted = Expression.Convert(selector.Body, typeof(int?));
            var typed = Expression.Lambda>(converted, selector.Parameters);

            return source.Max(typed) ?? 0;
        }