Laravel how to join one to many relationship tables - mysql

Question

I am using Laravel 5.5 and I want to display list of data by joining tables that have one to many relationship.
Currently, I do this by going through the loop and make queries to retrieve data. This way, I think, is very inefficient, because if I were to display 1000 rows of data record, I will have to go 1000 loops to append other data with one-to-many relationship.
I am thinking to get around this problem using cache but it does not seem to solve fundamental problem.
For more understanding I have shared tables that I want do join as below.
Post Table
| id | comment_id | status |
|----|------------|--------|
| 1 | 1 | 0 |
| 2 | 2 | 0 |
| 3 | 3 | 1 |
| 4 | 4 | 0 |
| 5 | 5 | 1 |
| 6 | 6 | 1 |
Comment Table
| id | order_id | content |
|----|----------|----------|
| 1 | 1 | hi |
| 2 | 1 | hellow |
| 3 | 1 | yes |
| 4 | 1 | okay |
| 5 | 2 | bye |
| 6 | 2 | good bye |
If I were to join Table Post with Table Comment, because they have one to many relationship, rows would not match. How would I join these two tables to show the list of post with comments?
Sample List Controller
/**
* #param Request $request
* #return \Illuminate\Http\JsonResponse
*/
public function list(Request $request)
{
$vaildData = $request->validate([
'comment_id' => 'numeric',
]);
$posts = new PostModel;
$posts->find(1);
$displayPosts = [];
foreach ( $posts->find(1)->get() as $post ) {
$displayPosts->comments = $post->comment()->get();
}
return $displayPosts;
}
Post Model
namespace App\Model\Post;
use SoftDeletes;
use Illuminate\Database\Eloquent\Model;
class Post extends Model
{
public function comments()
{
return $this->hasMany('App\Model\Post\Comment’, ‘post_id', 'id');
}
}

Answer 1

Use with() for eager loading your comments.
$posts = PostModel::with('comments')->find($id);
So your function will be like-
public function list(Request $request)
{
$vaildData = $request->validate([
'comment_id' => 'numeric',
]);
$posts = PostModel::with('comments')->find(1);
return $displayPosts;
}
You can filter your comments with comment_id using whereHas() like the following-
$comment_id = $request->input('comment_id');
$posts = PostModel::with('comments')->whereHas('comments', function ($query) use($comment_id)
{
$query->where('id', '=', $comment_id);
})->find(1);

Answer 2

https://laravel.com/docs/5.1/eloquent-relationships
Firstly, you may refer to this documentation.
To setup one-to-many relationship for Post and Comment table:
A Post has Many Comments
So in you Comment table there should be a column named post_id
Inside your Post.php
public function comments()
{
return $this->hasMany('App\Comment’);
}
Inside your controller
public function list(Request $request){
$posts = Post::where('id', 1)
->with('comments')
->get()
return $posts;
}

Answer 3

public function list(Request $request, $id)
{
$vaildData = $request->validate([
'comment_id' => 'numeric',
]);
$posts = PostModel::find($id);
return $posts->comments;
}
try this... Hope this can help you
or you can try like this
public function list(Request $request, $id)
{
$vaildData = $request->validate([
'comment_id' => 'numeric',
]);
$posts = PostModel::find($id)->comments()->get();
return $posts;
}

Answer 4

public function list(Request $request)
{
$vaildData = $request->validate([
'comment_id' => 'numeric',
]);
$posts = new PostModel;
$results = $posts->find(1)->with('comments')//comments is the function name you defined in the App\Model\Post
return resurts;
}
collection results contain the infomation of the post and another extra comment collection that belong to the post