使用 eloquent 和 laravel 从多个 sql 表中获取数据

Question

What i want to achieve?

Show user which pacts he is following.

What I am trying

I have designed two tables which are 'pacts' & 'pacts_follwers'

Table 'pacts' has the details of all the pacts

Table ' pacts_follwers ' has details of users following a particular pact .

These links will give you the images of both the tables

For Schema Refer Images

So how to get pacts that user is following.

What I have tried?

Sql Query

SELECT pacts.*, (SELECT pactsid FROM pacts_follwers WHERE pacts.id = pacts_follwers.pactsid
and pacts_follwers.userid = 2 ) as pactID FROM `pacts`

Sql query Result

This query will give pactId some value, where the value is null means the user is not following that pact. If this is the solution then i would need Eloquent for this which i am unable to make .

1st table pacts

id
title
about
created_at
updated_at
pactsImage

2nd table pacts_follwers

id
pactsid
userid
created_at
updated_at

Controller Code

$pacts = DB::select("SELECT pacts.*, (SELECT pactsid FROM pacts_follwers WHERE pacts.id =
pacts_follwers.pactsid and pacts_follwers.userid = ".Auth::id()." ) as pactID FROM `pacts`");

Answer 1

You need to setup hasManyThrough relationship for User and Pact.

class User extends Model {

   public function pacts() {
      return $this->hasManyThrough(
           Pact::class,
           PactFollower::class
           'userid',
           'pactsid'
      );
   }
}

I don't fully understand if you want to achieve "get user's all pacts" or "if pact is followed by user". Either way, you need to setup related relationships.

---

Or really simple (and not efficient way)

class Pact extends Model {

    public function followers() {
       return $this->hasMany(PactFollower::class, 'pactsid')
    }
}

Now you can use something like

$userIdsForPact = Pact::followers()->pluck('userid');

if ($userIdsForPact->has($user->id)) {
 // your operation
}

---

Edit: For "if pact is followed by user", you need to setup belongsToThrough relationship. It doesn't come out of the box with Laravel but staudenmeir/belongs-to-through package should serve you well.

After setting the relationship properly, you can use something like this.

Pact::with('user')->get();

Or add some methods in your Pact model:

public function followedByUser($user) {
    return $this->users->has($user);
}