Laravel - Nested relationship, order parent model by most recent nested - php

Question

Having a hard time understanding how to order my Laravel model by a nested relationship.
Here are the Models.
User.php
// Has many small_groups through a pivot table
public function small_groups()
{
return $this->belongsToMany('App\Models\SmallGroup')->withPivot('type')->withTimestamps();
}
SmallGroup.php
// Has many SmallGroupLessons
public function small_group_lessons()
{
return $this->hasMany('App\Models\SmallGroupLesson');
}
SmallGroupLessons.php
// Has many SmallGroupLessonComments
public function small_group_lesson_comments()
{
return $this->hasMany('App\Models\SmallGroupLessonComment');
}
SmallGroupLessonsComment.php
// Belongs to SmallGroupLesson
public function small_group_lesson()
{
return $this->belongsTo('App\Models\SmallGroupLesson');
}
What's I'm trying to do, is pull all of the user's small groups, ordered by the most recent SmallGroupLessonComment if one exists. I've been doing some research, and it sounds like using Laravels ORM in this use case will not work. However, I'm not entirely sure on how to create the join on the nested relationship.
I tried the following, but this only pulls in the most latest SmallGroupLessonComment, however, it does not order the entire result set.
$small_groups = $user->small_groups()->with([
'small_group_lessons' => function($q) {
$q->with([
'latest_comment' => function($q) {
$q->orderBy('created_at', 'asc');
}
]);
}
])->paginate($limit);
Update
Was able to solve it via the following...
$small_groups = $user->small_groups()->with([
'small_group_lessons' => function($q) {
$q->with([
'latest_comment' => function($q) {
$q->orderBy('created_at', 'asc');
}
]);
}
])
->leftJoin('small_group_lessons', 'small_group_lessons.small_group_id', '=', 'small_groups.id')
->leftJoin('small_group_lesson_comments', 'small_group_lesson_comments.small_group_lesson_id', '=', 'small_group_lessons.id')
->orderBy('small_group_lesson_comments.created_at', 'desc')
->paginate($limit);
Update #2
The above doesn't work. I get multiple small groups back that are the same item.
Update #3
This query is pretty close, but it's just ordered by the most recent SmallGroupLesson. Ideally, we order by the SmallGroupLessonComment 🤔
$small_groups = $user->small_groups()->with(
[
'small_group_lessons' => function($q) {
$q->with('latest_comment');
$q->orderBy('created_at', 'desc');
}
],
)
->orderBy(
SmallGroupLesson::select('created_at')
->whereColumn('small_group_id', 'small_groups.id')
->orderBy(SmallGroupLessonComment::select('created_at')
->whereColumn('small_group_lesson_id', 'small_group_lessons.id')
->orderBy('created_at', 'desc')
->limit(1), 'desc')
->limit(1), 'desc'
)
->paginate();

Answer 1

$data=User::select('*')->leftJoin('small_group_lessons','small_group_lessons.user_id','user.id')
->ordeBy('small_group_lessons.created_at','DESC')->get();
try like this

Answer 2

I was able to solve it via the following. Ordering based off the latest comment now works correctly.
$small_groups = $user->small_groups()->with([
'small_group_lessons' => function($q) {
$q->with('latest_comment');
$q->orderBy('created_at', 'desc');
}],
)
->orderBy(
SmallGroupLesson::select('small_group_lesson_comments.created_at')
->join('small_group_lesson_comments', 'small_group_lessons.id', '=', 'small_group_lesson_comments.small_group_lesson_id')
->whereColumn('small_group_id', 'small_groups.id')
->latest()
->limit(1), 'desc'
)
->paginate();