relationship - In yii2 How do we call through relations -

for example there a, b, c, d, e, f tables.

a has a_id foreign key in b. b has a_id , c_id foreign key. c has d_id foreign key. d has e_id foreign key.

now how write relation d. has no direct relation d.

from c write relation below.

    public function c {    return $this->hasmany(c::classname(), ['c_id' => 'c_id'])             ->via('b'); } 

how through relations d?? cannot find syntax anywhere online.. thanks..

i had similar problem when started yii2 have have relation b, b c , c d connection , on models. function in this( added in model main id wich id_a):

public function b {    return $this->hasmany(b::classname(), ['a_id' => 'id_a'])  } 

the same b c, in model b have:

public function c     {        return $this->hasmany(c::classname(), ['id_c' => 'c_id'])      } 

remember connection c::classname(), ['id_c' => 'c_id'] column next model need model are, data have related. after need set app search model main model( ). search have this. first add in search model:

public $id_c public $c_id ... 

all variables add other models. , after add them in firs row in

public function rules()     {         return [            [[......, 'id_c','c_id'...(all var need)  ]]            .....] } 

after add of them in first row(it make them safe) go to

public function search($params)     { $query = a::find()       ->select(...)       ->where (...)       ->joinwith(b)->joinwith(a.b)->joinwith(a.b.c).... how many need.       ;