php - Complex Associations - CakePHP 3.x [ Nested belongsToMany] -

i have complex joining like

a belongs many b threw ab table ab belongs many c threw abc table

now problem how can data in controller contain result till table abc. not finding direct relation in , table abc

my database structure is

table (id, name, code) table b (id, name, code) table c (id, name, code) table ab (id, a_id, b_id, fee) table abc (ab_id, c_id, opt_date, tno)

i can connect b using below query not sure how data abc

    $this->a->find('list',[ contain => ['b']     ]); 

here changing real scheme

1. courses (id, name, course_code, etc...) 2. sessions (id, name, status, start_date, end_date) 3. seats (id, name, description, metadata, status) 4. courses_sessions (id, course_id, session_id, programme_coordinator, academic_coordinator, status) 5. courses_sessions_seats (id, courses_session_id, seats_id, no_seats) 

current relations

a) courses belongstomany sessions using courses_sessions b) courses_sessions belongstomany seats using courses_sessions_seats 

i don't know if case 2 possible on not, want show course details available seats per category session wise.

in short this

$this->a     ->find()     ->contain([       'b' => ['c']       ]); 

or

$this->a     ->find()     ->contain([       'b' => function($q) {          return $q->contain(['c']);           }]); 

you can read here in docs

edit

what think table schema

1. courses_sessions
   • course_sessions belongsto course
   • course_sessions belongsto session
2. courses_sessions_seats
   • courses_sessions_seats belongsto course_sessions
   • courses_sessions_seats belongsto seats

if make models in way, have more control on queries later.

edit2

to obtain data perspective of courses case use

$courses = $this->courses   ->find()   ->contain([     'coursessessions' => ['sessions', 'sessionsseats']   ]); foreach ($courses $course) :   // code here endforeach; 

it easy