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

Default values cannot be supplied for parameters that are not declared 'optional'

 Function GetFindBooks(id As Integer, ByVal pid As Integer, Optional sort As String = "DESC", Optional limit As Integer = 99)

In your WebApiConfig

 config.Routes.MapHttpRoute( _
          name:="books", _
          routeTemplate:="api/{controller}/{action}/{id}/{pid}/{sort}/{limit}", _
          defaults:=New With {.id = RouteParameter.Optional, .pid = RouteParameter.Optional, .sort = UrlParameter.Optional, .limit = UrlParameter.Optional} _
      )