What is the best way to check IQueryable result set is null

Question

I just want to know what is the best way to check if an IQueryable result has no values.

eg. if we have a method like

public static IQueryable<Table> DisplayAll() {     var db = new DataContext();     var list= from data in db.Table select data;     return list; } 

and then we do something like this

var list = DisplayAll(); if(list != null) {      //do something --- in here even if the result set has no values it will      // go to this line. It just say `enumeration yielded no results` } 

Any possible way to check the result set has content or not??

Thanks

Answer 1

list will never be null with LINQ; it will simply represent an "empty collection" if need be. The way to test is with the Any extension method:

if (list.Any()) {     // list has at least one item } 

Answer 2

An exception will be thrown if IQueryable yeilds no result. I use:

using System.Data.Entity; //for Async support in EF var tQ = await _tableRepository.DisplayAll(); try { return await tQ.ToListAsync(); } catch { return null; } 

to trap the exception and return null; or an empty List if you prefer,

catch { return new List<Table>(); }