Count - Nested

Query

public void Linq76()
{
    List customers = GetCustomerList();
  
    var orderCounts =
        from c in customers
        select new { c.CustomerID, OrderCount = c.Orders.Count() };
  
    ObjectDumper.Write(orderCounts);
}

Lambda Expression

public void Linq76()
{
    List customers = GetCustomerList();
 
    var orderCounts = customers.Select(cust => new {cust.CustomerID, OrderCount = cust.Orders.Count()});
 
    ObjectDumper.Write(orderCounts);
}

Output

CustomerID=ALFKI OrderCount=6
CustomerID=ANATR OrderCount=4
CustomerID=ANTON OrderCount=7
CustomerID=AROUT OrderCount=13
CustomerID=BERGS OrderCount=18
CustomerID=BLAUS OrderCount=7
CustomerID=BLONP OrderCount=11
CustomerID=BOLID OrderCount=3
CustomerID=BONAP OrderCount=17
CustomerID=BOTTM OrderCount=14
CustomerID=BSBEV OrderCount=10
CustomerID=CACTU OrderCount=6
CustomerID=CENTC OrderCount=1
CustomerID=CHOPS OrderCount=8
CustomerID=COMMI OrderCount=5
CustomerID=CONSH OrderCount=3
CustomerID=DRACD OrderCount=6
CustomerID=DUMON OrderCount=4
CustomerID=EASTC OrderCount=8
CustomerID=ERNSH OrderCount=30
CustomerID=FAMIA OrderCount=7
CustomerID=FISSA OrderCount=0
CustomerID=FOLIG OrderCount=5
CustomerID=FOLKO OrderCount=19
CustomerID=FRANK OrderCount=15
CustomerID=FRANR OrderCount=3
CustomerID=FRANS OrderCount=6
CustomerID=FURIB OrderCount=8
CustomerID=GALED OrderCount=5
CustomerID=GODOS OrderCount=10
CustomerID=GOURL OrderCount=9
CustomerID=GREAL OrderCount=11
CustomerID=GROSR OrderCount=2
CustomerID=HANAR OrderCount=14
CustomerID=HILAA OrderCount=18
CustomerID=HUNGC OrderCount=5
CustomerID=HUNGO OrderCount=19
CustomerID=ISLAT OrderCount=10
CustomerID=KOENE OrderCount=14
CustomerID=LACOR OrderCount=4
CustomerID=LAMAI OrderCount=14
CustomerID=LAUGB OrderCount=3
CustomerID=LAZYK OrderCount=2
CustomerID=LEHMS OrderCount=15
CustomerID=LETSS OrderCount=4
CustomerID=LILAS OrderCount=14
CustomerID=LINOD OrderCount=12
CustomerID=LONEP OrderCount=8
CustomerID=MAGAA OrderCount=10
CustomerID=MAISD OrderCount=7
CustomerID=MEREP OrderCount=13
CustomerID=MORGK OrderCount=5
CustomerID=NORTS OrderCount=3
CustomerID=OCEAN OrderCount=5
CustomerID=OLDWO OrderCount=10
CustomerID=OTTIK OrderCount=9
CustomerID=PARIS OrderCount=0
CustomerID=PERIC OrderCount=6
CustomerID=PICCO OrderCount=10
CustomerID=PRINI OrderCount=6
CustomerID=QUEDE OrderCount=9
CustomerID=QUEEN OrderCount=13
CustomerID=QUICK OrderCount=28
CustomerID=RANCH OrderCount=5
CustomerID=RATTC OrderCount=18
CustomerID=REGGC OrderCount=12
CustomerID=RICAR OrderCount=11
CustomerID=RICSU OrderCount=10
CustomerID=ROMEY OrderCount=5
CustomerID=SANTG OrderCount=6
CustomerID=SAVEA OrderCount=31
CustomerID=SEVES OrderCount=9
CustomerID=SIMOB OrderCount=7
CustomerID=SPECD OrderCount=4
CustomerID=SPLIR OrderCount=9
CustomerID=SUPRD OrderCount=12
CustomerID=THEBI OrderCount=4
CustomerID=THECR OrderCount=3
CustomerID=TOMSP OrderCount=5
CustomerID=TORTU OrderCount=10
CustomerID=TRADH OrderCount=7
CustomerID=TRAIH OrderCount=3
CustomerID=VAFFE OrderCount=11
CustomerID=VICTE OrderCount=10
CustomerID=VINET OrderCount=4
CustomerID=WANDK OrderCount=10
CustomerID=WARTH OrderCount=15
CustomerID=WELLI OrderCount=9
CustomerID=WHITC OrderCount=14
CustomerID=WILMK OrderCount=8
CustomerID=WOLZA OrderCount=7