CODEWITHSUNDEEP
phplaraveleloquent
Matt Komarnicki
Matt Komarnicki

Reputation: 5422

Laravel 8: Can I make Eloquent scope but NOT against query builder but against related model?

I have a model - let's call it Parent.

Each Parent can have many children.

public function children(): HasMany
{
    return $this->hasMany(Child::class, 'parent_id', 'id');
}

I want to make a scope for Parent called "active".

My requirement goes as follows:

Parent is active when it has at least 1 child.

I've done local scopes multiple times and I know that within Parent.php I can do something like:

public function scopeActive($query)
{
    return $query->where(…);
}

But as you see, $query is a \Illuminate\Database\Eloquent\Builder which is not my case. I want to operate on related model somehow, not the DB query.

Can I do this in a clean way without fetching all parents with('child') and within ->filter() forgetting those that have no children? When there will be 1000 parents but only one will have children, it will simply waste DB resources (by fetching 999 redundant parents).

Upvotes: 2

Views: 900

Answers (4)

user3532758
user3532758

Reputation: 2271

One option is to use whereHas in scope:

public function scopeActive($query){
  return $query->whereHas('children');
}

OR

public function scopeActive(){
  return $this->whereHas('children');
}

And

Parent::active()->with('children')->get();

should give you all Parents who have children and along with respective children

Upvotes: 2

Cameron
Cameron

Reputation: 554

In Parent

public function getActiveAttribute() {
  return $this-> children()->exists();
}

In code

$parent = new Parent;
if($parent->active){//true}

You can also use count

count($this->children); // 0 evaluates to false

a related thread here if you need: Laravel Check If Related Model Exists

Upvotes: -1

Nicklas Kevin Frank
Nicklas Kevin Frank

Reputation: 6337

You can use the following query

public function scopeActive($query)
{
    return $query->has('children');
}

Upvotes: 2

Swapnil Bhikule
Swapnil Bhikule

Reputation: 606

Can you try something like:

public function getActiveAttribute() {
  return $this->children()->count() > 1;
}

This can be used like,

$parent->active

And the query will only be made when you'll try to access the active property on the Parent model, not when you will be fetching all parents.

Upvotes: -1

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