LINQ Include vs Join. Are they equivalent?

Question

I have used join in linq to join 2 tables. What is the difference between a join and Include. From what I see, they both behave the same.

    Include vs. Joi         


        

Answer 1

If you simply need all Orders for some Customers. Good example here for blog application is displaying all Comments below Articles always. Then Include is your way of work.

Join in opposition is more helpful if you need some Customers and filters out them using some data contained in Orders entity. For example you want to sort out Articles to send to the Police Articles with Comments containing vulgar words.

Also if your Orders entity contains a lot of data (many columns) taking a lot of memory and you don't need all of them then join can be much more efficient but here always is a question what "lot of data" or "many columns" means so test first will be the best choice.