asp.net mvc - Advanced Search in LINQ Query -

i want make advanced search (filtering) using different criteria. example, if first name available query should return available matches. if first name , last name both available should match first name or last name , similar way many criteria (gender, profession, education etc.)

here controller method in taking ajax data parameters.

 [httppost]     public actionresult search(string cno, string fname, string lname, string male, string female, string stateid, string cityid, string professionid, string educationid)     {         if (request.isajaxrequest())         {             var db = new clubdatacontext();              /*----------advanced search query-------------*/              return partialview("serachresult");         }         else             return redirecttoaction("index", "home");     } 

it may possible parameters have null value. please suggest linq query suitable in situation.

you have option use c# null-coalescing operator

users.where(x => x.firstname == (fname??x.firstname) || x.lastname == (lname?? x.lastname)).tolist(); 

further

users.where(x => x.firstname.contains(fname??x.firstname) || x.lastname.contains(lname?? x.lastname)).tolist(); 

equivalent sql :

select * user u       u.firstname = isnull(@fname,u.firstname)            or u.lastname = isnull(@lname,u.lastname)