Laravel 5.2 Eloquent - 通过多种关系查找所有id

Question

So here are my relationships:

A fund belongs to a planCode

A planCode belongs to a planType

What I need to do is find the fund_id's that are a part of certain plan types. I tried something like this:

$plans = (new 'App\\PlanType')->with('planCode.fund')->whereIn('code', ['PENS', 'ANN', 'WEL'])->get();

With this I get the three plan codes with their relationships eager loaded. What I want is a list of all the fund_id's. I tried $plans->lists('planCode.fund.fund_id', 'code') but this returns null for the fund_id. Any ideas?

Answer 1

So if your relationships are like this -

PlanCode has many Funds

Fund belongs to a PlanCode

PlanType has many PlanCodes

PlanCode belongs to a PlanType

Then you can add another relationship like this -

PlanType has many Funds through PlanCodes

UPDATE

After adding a function like this to your PlanType class -

public function funds() {
    return $this->hasManyThrough('fund', 'planCode', PT, PC);
}

You can simply access Funds on your PlanType model like this -

$planType->Funds

Take a look at the docs here .

Answer 2

Yep, atefth has it in one. Laravel has a really useful relationship so that you don't have to make repeated queries to the database to get relations of relations. This is the hasManyThrough relationship.

So here, for example, your planType model has many fund models through the planCode model. Your planType model should contain a funds method that looks like this, where PC is the planCode->id column name in the fund table, and PT is the planType->id column in the planCode table:

public function funds() {
    return $this->hasManyThrough('fund', 'planCode', PT, PC);
}

You may have to fully namespace your models, depending on the structure of your application.