Cross Join
This sample shows how to efficiently join elements of two sequences based on equality between key expressions over the two.
public void Linq()
{
string[] categories = new string[]{
"Beverages",
"Condiments",
"Vegetables",
"Dairy Products",
"Seafood" };
List<Product> products = GetProductList();
var q =
from c in categories
join p in products on c equals p.Category
select new { Category = c, p.ProductName };
foreach (var v in q)
{
Console.WriteLine(v.ProductName + ": " + v.Category);
}
}
Group Join
Using a group join you can get all the products that match a given category bundled as a sequence.
public void Linq103()
{
string[] categories = new string[]{
"Beverages",
"Condiments",
"Vegetables",
"Dairy Products",
"Seafood" };
List<Product> products = GetProductList();
var q =
from c in categories
join p in products on c equals p.Category into ps
select new { Category = c, Products = ps };
foreach (var v in q)
{
Console.WriteLine(v.Category + ":");
foreach (var p in v.Products)
{
Console.WriteLine(" " + p.ProductName);
}
}
}