Question

Having trouble with this, I’ve tried following several examples but I am just not getting it. It makes perfect sense using the non-lambda way, but how do I do a join using lambda expressions?

var myCats = GetAllCats();
var myHouses = GetAllHouses();

// pseudosql:  select * from a inner join b on a.id = b.id

I have tried this:

var fullData = myCats.Join(myHouses, a => a.id, b => b.id, (a, b) => a);

which I kind of got through looking at other examples on SO, but fullData is type IEnumerable<Cat> so I can’t pull any properties from Houses off it.

Answer 1

var fullData = myCats.Join(
                 myHouses, 
                 cat => cat.id, 
                 house => house.id, 
                 (cat, house) => 
                   new 
                   { 
                     Cat = cat, 
                     House = house 
                   });

Access via fullData.First().Cat... or fullData.First().House....