Laravel / Eloquent : hasManyThrough WHERE

问题

In the documentation of Eloquent it is said that I can pass the keys of a desired relationship to hasManyThrough.

Lets say I have Models named Country, User, Post. A Country model might have many Posts through a Users model. That said I simply could call:

$this->hasManyThrough('Post', 'User', 'country_id', 'user_id');

This is fine so far! But how can I get these posts only for the user with the id of 3 ?

Can anybody help here?

回答1:

So here it goes:

models: Country has many User has many Post

This allows us to use hasManyThrough like in your question:

// Country model
public function posts()
{
  return $this->hasManyThrough('Post', 'User', 'country_id', 'user_id');
}

You want to get posts of a given user for this relation, so:

$country = Country::first();
$country->load(['posts' => function ($q) {
  $q->where('user_id', '=', 3);
}]);
// or
$country->load(['posts' => function ($q) {
  $q->has('user', function ($q) {
    $q->where('users.id', '=', 3);
  });
})

$country->posts; // collection of posts related to user with id 3

BUT it will be easier, more readable and more eloquent if you use this instead: (since it has nothing to do with country when you are looking for the posts of user with id 3)

// User model
public function posts()
{
  return $this->hasMany('Post');
}

// then
$user = User::find(3);
// lazy load
$user->load('posts');
// or use dynamic property
$user->posts; // it will load the posts automatically
// or eager load
$user = User::with('posts')->find(3);

$user->posts; // collection of posts for given user

To sum up: hasManyThrough is a way to get nested relation directly, ie. all the posts for given country, but rather not to search for specific through model.

回答2:

$user_id = 3;

$country = Country::find($country_id);

$country->posts()->where('users.id', '=', $user_id)->get();

回答3:

$this->hasManyThrough('Post', 'User', 'country_id', 'user_id')->where(column,x);

What happen here is you get the collection in return you can put any condition you want at the end.

来源：https://stackoverflow.com/questions/24388688/laravel-eloquent-hasmanythrough-where

标签

php

laravel

relational-database

eloquent