Optional query string parameters in ASP.NET Web API

Question

I need to implement the following WebAPI method:

/api/books?author=XXX&title=XXX&isbn=XXX&somethingelse=XXX&date=XXX

All of

Answer 1

Use initial default values for all parameters like below

public string GetFindBooks(string author="", string title="", string isbn="", string  somethingelse="", DateTime? date= null) 
{
    // ...
}