how to join two select in linq c# mvc
I try join two select to return the rows from a table which contain certain keywords. with below code 

        public IQueryable<ipost> getpost()
        {
               //get the list of desirable keywords
               IQueryable<ipost> secondkeywords = allkeywords();

               //try to find the rows which contain desirable keywords
               var thepost = 
    db.iposts.Where(post.ikeywords.Contains(secondkeywords.Select (x=>x.ikeywords) ));
   
           return thepost;
       
        }

but it did not work , what should I write in *Contain* method ?

Tanx 
how to join two select in linq c# mvc
===

I try join two select to return the rows from a table which contain certain keywords. with below code 

        public IQueryable<ipost> getpost()
        {
               //get the list of desirable keywords
               IQueryable<ipost> secondkeywords = allkeywords();

               //try to find the rows which contain desirable keywords
               var thepost = 
    db.iposts.Where(post.ikeywords.Contains(secondkeywords.Select (x=>x.ikeywords) ));
   
           return thepost;
       
        }

but it did not work , what should I write in *Contain* method ?

Tanx 