laravel - Relationship results automatically coming out? -

i have series of relations on model, here 1 of them.

class product extends model{      public function user(){         return $this->belongstomany('\app\user');     } } 

i rows with:

$data = product::all() 

and these looped through so:

 foreach ($data $value) {      var_dump($value->title);  } 

my understanding if wished relational data come out, need like:

$data = product::with('user')->get(); 

but without above , doing all() still can access user:

foreach ($data $value) {      var_dump($value->title->user);  } 

why this?

relationship results automatically coming out?

no, when do

$data = product::all(); foreach ($data $value) {   var_dump($value->title); } 

you doing this:

select * products 

but on foreach, since trying access property wasn't loaded, doing new query, behind scenes laravel fetching user. represents n + 1 query problem, if have 25 products run 26 queries (25+1):

select * products select * users id = ? (x25) 

that's why have eager loading option,

$data = product::with('user')->get(); foreach ($data $value) {      var_dump($value->title->user);  } 

doing running 2 queries

select * products  select * users id in (1, 2, 3, 4, 5, ...) 

so it's choose method use, if aren't iterating products users, eager loading unnecessary , usual all() fine;