Laravel Eloquent - get count of another table - php

Question

I have an eloquent model "Athlete" and there is another table performances. Each athlete has 0 to many performances. And I would like get best performance of each athlete(personal best) or null if the athlete doesnt have any performances yet.
My athlete model:
class Athlete extends Model
{
// I would like to do something like
public $personalBest = max(performances) - the highest perfomance
/**
* The table associated with the model.
*
* #var string
*/
protected $table = 'athletes';
/**
* The primary key associated with the table.
*
* #var string
*/
protected $primaryKey = 'id';
/**
* Indicates if the model should be timestamped.
*
* #var bool
*/
public $timestamps = false;
/**
* Get the performances for the Athelete post.
*
* #return HasMany
*/
public function performances()
{
return $this->hasMany('App\EloquentModels\Performance', 'athlete_id', "id");
}
}
I would like to get the highest performance of each athlete. Hope it does make sense.
I think it has to be answered somewhere but I had no luck finding it. So sorry if I just failed to find it.
Performances table
id(int) year(int) performance(float)
-------------------------------------
1 2000 257.3
2 2001 227.3
Just to wrap things up. Posting the final raw query which was generated:
select [athletes].[first_name], [athletes].[last_name], MAX(performance) AS personal_best
from [athletes]
left join [performances] on [athletes].[id] = [performances].[athlete_id]
group by [athletes].[id], [athletes].[first_name], [athletes].[last_name]
order by [personal_best] desc

Answer 1

Using withCount should do the job
$athletes= App\Athlete::withCount('performances')->get();
foreach ($athletes as $athlete) {
echo $athlete->performances_count;
}
If you want max performance, you can do something like
$athletes= App\Athlete::all();
foreach ($athletes as $athlete) {
echo $athlete->performances->pluck('performance')->max();
}
Something like
select e.athelete.id, max(perf.performace) as max_performace
from atheletes ath
left join performaces perf on ath.id = perf.athelete_id
group by ath.id, max_performace
may be something like
DB('athletes as ath')::leftJoin('performaces as perf', 'ath.id', 'perf.athelete_id')->select(e.athelete.id, max(perf.performace) as max_performace)->orderBy('max_performace');
You can use order by max_performace, if you need.
I think you can also use simply
echo $athlete->performances->max('performance');