LINQ CHEAT SHEET
Query Syntax
Lambda Syntax
Filtering
var col = from o in Orders
where o.CustomerID == 84
select o;
var col2 = Orders.Where(o => o.CustomerID == 84);
Return Anonymous Type
var col = from o in orders
select new
{
OrderID = o.OrderID,
Cost = o.Cost
};
var col2 = orders.Select(o => new
{
OrderID = o.OrderID,
Cost = o.Cost
}
);
Ordering
var col = from o in orders
orderby o.Cost ascending
select o;
var col2 = orders.OrderBy(o => o.Cost);
var col3 = from o in orders
orderby o.Cost descending
select o;
var col4 = orders.OrderByDescending(o => o.Cost);
var col9 = from o in orders
orderby o.CustomerID, o.Cost descending
select o;
var col6 = orders.OrderBy(o => o.CustomerID).
ThenByDescending(o => o.Cost);
//returns same results as above
var col5 = from o in orders
orderby o.Cost descending
orderby o.CustomerID
select o;
//NOTE the ordering of the orderby’s
Joining
var col = from c in customers
join o in orders on
c.CustomerID equals o.CustomerID
select new
{
c.CustomerID,
c.Name,
o.OrderID,
o.Cost
};
var col2 = customers.Join(orders,
c => c.CustomerID,o => o.CustomerID,
(c, o) => new
{
c.CustomerID,
c.Name,
o.OrderID,
o.Cost
}
);
Grouping
var OrderCounts = from o in orders
group o by o.CustomerID into g
select new
{
CustomerID = g.Key,
TotalOrders = g.Count()
};
var OrderCounts1 = orders.GroupBy(
o => o.CustomerID).
Select(g => new
{
CustomerID = g.Key,
TotalOrders = g.Count()
});
NOTE:
the grouping’s key is the same type as the grouping value. E.g. in above example grouping key is an int because o.CustomerID is
an int.
