I have a table called post that HAS MANY comments I need to sort the list of post by how many comments there are in a post.
In fuelPHP, is there a way to do this in ORM? I want to make sure before I do it manually.
Thanks.
Short answer for this: No, there's not. It is not possible for the ORM to sort for you like that without doing it manually.
To work around it:
// construct an array with post-id => comment-count
$ordered = array();
foreach($posts as $id => $post)
{
$ordered[$id] = count($post->comments);
}
// order the array, largest count first
arsort($ordered, SORT_NUMERIC);
// merge the posts in, maintaining order
$ordered = array_replace($ordered, $posts);
This uses takes advantage of the feature that array_replace will maintain the key order of the first array.
Related
I have a challenge that if I want to sort the records when getting using Laravel's ORM based on a list of IDs, how should I do it?!!!!!!!
I mean :
Suppose we have a table called users, which contains 100 records and each record has a unique ID.
We also have an array of IDs.
$ids = [4,1,2,3]
Now I want to get the list of users, but only the users who are first in the ids array and secondly according to the same order as they are listed in this array.
User::whereIn('id' , $Ids)->sortBy('id',$ids)->get();
Can you think of a solution to do this?
User::whereIn('id' , $Ids)->sortBy('id',$ids)->get();
The collections sortBy() function can take a custom call back this way:
$users = User::whereIn('id', $Ids)->get()
->sortBy(function($user, $key) use($ids) {
return array_search($user->id, $ids);
});
This will sort your collection according to the given array.
You can also reference the docs for more information.
Note that the sortBy() function must act upon a collection, which means that the get() function must come before it.
There's the save and saveMany methods on the HasMany relation class, but where are the dissociate(Many)/detach(Many) methods? There's also no built-in way to get the inverse relationship method, so what's the best way to dissociate an array of id's/models from a HasMany relationship object.
Currently I'm using:
$hasMany = $parent->theRelationship(); // Get the relationship object.
$child = $hasMany->getRelated(); // Get an empty related model.
$key = $hasMany->getForeignKeyName(); // Get the name of the column on the child to set to NULL.
$child->findMany($IDs)->each(function($model) use ($key) {
$model->$key = NULL;
$model->save();
});
This could be alot shorter with something like:
$hasMany = $parent->theRelationship();
$hasMany->dissociate($IDs);
Bonus points if you have any official answers from Taylor as to why he hasn't implemented this, I've seen him close feature requests of this kind on GitHub.
I am not sure why there isn't a function, but to be more performant than your example, you could use the DB class like:
\DB::table('child_table')->where('parent_id', $parent->id)->update(['parent_id' => null]);
You could use detach like so;
$parent->theRelationship()->detach([1,2,3])
Where you pass an array of IDs.
From Laravel documentation:
"For convenience, attach and detach also accept arrays of IDs as input"
The performatic way (1 db update):
$partent->theRelationship()->update(['parent_id' => null]);
The readable way (multiple db updates):
$parent->theRelationship->each->parentRelationship()->dissociate();
I have an array of ids that i want to sort a given column by them in the collection.
For example,
$suppliersOrder = [8,7,5,1,3,4];
$items = Items::get()->sortBy(function($model) use ($suppliersOrder) {
return array_search($model->supplier_id, $suppliersOrder);
})->values();
This acts like ordering items as [1,3,4,5,7,8] instead of the given order. And if I try sortByDesc, likewise [8,7,5,4,3,1] but I couldn't figure out the way to actually sort them as my given array's order.
My ultimate goal is then running $items->groupBy('supplier.name') so I can have my desired order.
What Alexander Villalobos suggested in the comments, I changed my code like this:
$items = Items::get()->sortBy(function($model) use ($suppliersOrder) {
return rsort($model->supplier_id, $suppliersOrder);
});
Indirect modification of overloaded property App\Item::$supplier_id has no effect
$suppliersOrder = [8,7,5,1,3,4];
$items = Items::get()->sortBy(function($row,$key) use ($suppliersOrder) {
return array_search($row->supplier_id, $suppliersOrder);
});
This should give you sorted collection of items by the order you described in $suppliersOrder. As per Laravel docs, the parameters to the callback function include one being the row for the collection and another being the key of that row in the collection.
I'm sure this may be a simple solution, but I can't seem to work it out.
I am trying to use Laravel's where() clause to build an array of $courses that belong to each $student. I cycle through each $student and filter the $courseRecords to find matching courses based on their StudentCode.
Here is my sample code snippet:
// Cycle through the students and add their relevant course details
foreach( $students as $student ) {
// Find matching courses to the student
$courses = $courseRecords->where( 'StudentId', $student->StudentCode );
// Add the course array to the student record
$student->Courses = $courses;
}
However, the result I get, gives me each student's course, but with a leading index number (as shown below in random results):
I can't seem to work out why this is happening. The first entry (Id 0) is the result I am expecting, but for some reason, every other result seems to give me the matching index number of $courseRecord.
I have tried using $courses->all(); and $courses->toArray(); but this doesn't make any difference. From the Laravel documentation (that I have read), it doesn't mention this behaviour which makes me think I have something incorrect.
$students and $courseRecords are both a collection.
Use values():
$courses = $courseRecords->where('StudentId', $student->StudentCode)->values();
Using Laravel 5.3, I have a model with the following function
public function myData() {
return $this->hasMany(MyData::class);
}
and in my collection I have the following
$my_data = MyModel->myData()->get();
All good so far. If I return $my_data I get an eloquent collection with three items.
What I need now though is to create a duplicate of that collection but containing only three of the fields.
I have tried several different things, each of which return an error. The following is the closest I have got, but this returns an empty array - I assume because the fields are located one level deeper than the collection object.
$new_collection = $my_data->only(['field_1', 'field_2', 'field_3']);
What would be the correct way to create a new collection containing all three items, each with only the three selected fields?
Thanks for your help
You could use map:
$slimmed_down = $collection->map(function ($item, $key) {
return [
'field_1' => $item->field_1,
'field_2' => $item->field_2,
'field_3' => $item->field_3
];
});
This will return a new Collection with just the values you want. As far as I know there isn't any other method that does what you want, so iterating over every item and selecting the fields this way is one of the few solutions.
The advantage of using map instead of a standard foreach loop is that when you use map it returns a new instance of Collection.
Edit:
After some thoughts and research about this, the problem you'll have created is that the all the values in the Collection aren't instances of anything anymore. If you don't mind this effect, an even prettier and faster way would be to do this:
$slimmed_down = $collection->toArray()->only(['field_1', 'field_2', 'field_3']);
This basically has the same result.
Using Laravel 9, I just had the same issue :
$my_data->only(['field_1', 'field_2', 'field_3']);
returning an empty array.
I solved it with :
$my_data->map->only(['field_1', 'field_2', 'field_3']);