Question 16786 in Laravel Question posted in
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Laravel – latest() chained with where() behavior

So I have a many-to-many table with created_at and the foreign keys student_id and status_id.

For each student, I want to retrieve an entry only if the latest one has status_id = 1.

I tried it like this: (it’s a chain of queries, in this case $query would be Student::where(something else))

$query->whereHas('statusuri', function($query) use ($statusuri) {
                $query->latest('status_student.created_at')->where('status_id', 1);
});

(statusuri is the many-to-many relationship)

but I get a different result from what I need.

It does the where clause first and then latest(). Basically, it retrieves the last entry which matches the where.

I want to search for each student, the latest entry and if the where clause matches it, get that entry. If not, don’t return anything.

Is that possible with Eloquent?

Thanks.

Tags:

2

Answers


  1. 0

    Have you considered a "has one of many" relationship : https://laravel.com/docs/9.x/eloquent-relationships#advanced-has-one-of-many-relationships

    You can make a relationship in your Student model:

    public function latestStatus()
{
    return $this->hasOne(StatusStudent::class)->ofMany([
        'created_at' => 'max',
        'id' => 'max',
    ], function ($query) {
        $query->where('status_id', 1);
    });
}

    Edit: works only for Laravel 8+

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  2. 0

    In your case, you can use the where and latest methods together in a subquery, like this:

    $query->whereHas('statusuri', function($query) use ($statusuri) {
    $query->where(function($query) {
        $query->where('status_id', 1)
              ->latest('status_student.created_at');
    });
});
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