Laravel加载相关的类模型

Question

I need a comprehensive explanation on this excerpt from Martin Bean Laravel Essential :

  $breed = Furbook\Breed::with('cats') 
- >whereName($name) 
- >first() 

I understand all the method except with(). Pls explain in sql what the with('cat') is used for. Pls my code might not be formatted well because I used the app.

Answer 1

If you take a look at in documentation, you will see 'with' is for eager loading. It could be explained as follows.

select * from books where id = 1

select * from books where id = 2

select * from books where id = 3

select * from books where id = 4
....

This query is reduce to

select * from books

select * from authors where id in (1, 2, 3, 4, 5, ...)

which is more efficient.