Recursive foreign key in laravel [duplicate]

Question

I have the table tbl_relations with columns

id,user_name,relation_name,relation_name_id

tbl_relations table

relation_name_id is the foreign key referencing id in the same table.
In laravel I will select two inputs from id and need to get the collections of data from input one to till it's reach the second input using foreign key recursive method..is it possible?

This way I need to get the collection

You will have to need to use MySQL's 8 CTE and recursive queries that is your best option with this data model. — Raymond Nijland
– Raymond Nijland, Commented Mar 22, 2019 at 11:06
@RaymondNijland will you please convert this into laravel stackoverflow.com/questions/16542013/… — Piruthivi Raj
– Piruthivi Raj, Commented Mar 25, 2019 at 2:24

apokryfos · Accepted Answer · 2019-03-22 11:13:44Z

2

This solution is probably inefficient but it will work:

class Relation extends Model {
     protected $table = 'tbl_relations';
     protected $with = [ 'related' ];

     public function related() {
          return $this->hasOne(Relation::class, 'relation_name_id'); 
     }
}

Each time the Relation model is loaded it should trigger a loading of the related relation.

You can then do:

Relation::find(1)->related->related->id;

Note this solution does not take into account specific MySQL optimizations so will probably be the slowest possible solution.

answered Mar 22, 2019 at 11:13

apokryfos

40.9k11 gold badges83 silver badges128 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Piruthivi Raj Over a year ago

Thanks a lot but "Trying to get property 'related' of non-object " getting this error brother

apokryfos Over a year ago

I think it's to do with the direction. The idea is Relation has another relation meaning there's some relation where its relation_name_id is the id of this relation. In my example I used 1 as the ID but based on what you shared that probably won't work, however Realtion::find(2)->relation->id will probably return 1

Collectives™ on Stack Overflow

Recursive foreign key in laravel [duplicate]

1 Answer 1

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Linked

Related