c# - Select by ID from a list -

i have table of products , table of categories, can select id of category this:

var result = db.tblproducts.where(p => p.tblcategories.any(c => c.id == 1)); 

however, want able select based on list of categories:

 var catids = new list<int>() { 1,2,3 };   var results = db.tblproducts.where(r => r.tblcategories.any(t => catids.contains(t.id))); 

i following error:

linq entities not recognize method 'boolean contains(int32)' method, , method cannot translated store expression.

presumably because using contains compare entities local variables. there way this?

try create expression values. f.e.:

static expression makeorexpression<t, p>(expression<func<t, p>> whattocompare, ienumerable<p> values) {     expression result = expression.constant(true);      foreach (var value in values)     {         var comparison = expression.equal(whattocompare, expression.constant(value));         result = expression.or(result, comparison);     }      return result; } 

how use:

var results = db.tblproducts.where(r => r.tblcategories.any(makeorexpression(t => t.id, catids))); 

the method makeorexpression create expression t.id == 1 || t.id == 2 || t.id == 3 list { 1, 2, 3 } dynamically, , ef translate sql condition.