Laravel Query builder - select top 1 row from another table - mysql

Question

I have this SQL query for MySQL which works fine. But I need to rewrite it using query builder and need to avoid DB::raw() completely because development database is different from production. I know far from ideal, but unfortunately it is what it is.
SELECT athletes.*,
(
SELECT performance
FROM performances
WHERE athletes.id = performances.athlete_id AND performances.event_id = 1
ORDER BY performance DESC
LIMIT 0,1
) AS personal_best
FROM athletes
ORDER BY personal_best DESC
Limit 0, 100
And I'm struggling how to rewrite the personal_best part. I have table of performances for athletes and I need to select only the best performance for each athletes as his personal best.
I was trying to search for answer but all of the answers I found included raw adding raw SQL.
Any ideas or hint would be much appreciated.
Thank you in advance!
So I accepted I might have to use Eloquent for this, but still having trouble to progress. Heres my code:
class Athlete extends Model
{
/**
* 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');
}
}
class Performance extends Model
{
/**
* The table associated with the model.
*
* #var string
*/
protected $table = 'performances';
/**
* The primary key associated with the table.
*
* #var string
*/
protected $primaryKey = 'id';
/**
* Indicates if the model should be timestamped.
*
* #var bool
*/
public $timestamps = false;
}

Answer 1

Create a new connection at database.php like mysql_dev for development parameters.
DB::connection('mysql_dev')->table('athletes')
->leftJoin('performances','athletes.id','performances.athlete_id')
->where('performances.event_id',1)
->groupBy('athletes.id')
->orderByDesc('personal_best')
->select('athletes.*',DB::raw('MAX(performances.performance) AS personal_best')
->paginate(100);
try like this without raw,
DB::connection('mysql_dev')->table('athletes')
->leftJoin('performances','athletes.id','performances.athlete_id')
->where('performances.event_id',1)
->groupBy('athletes.id')
->orderByDesc('performances.performance')
->select('athletes.*','performances.performance'
->paginate(100);

Answer 2

If you are using raw SQL just do MAX for performance for each athlete using GROUP BY.
SELECT athletes.*, MAX(performance) AS personal_best
FROM athletes
INNER JOIN performances ON athletes.id = performances.athlete_id AND performances.event_id = 1
GROUP BY athletes.id
ORDER BY personal_best DESC
LIMIT 0, 100
Laravel Query Builder:
DB::table('athletes')
->join('performances', 'athletes.id', '=', 'performances.athlete_id')
->where('performances.event_id', '=', 1)
->groupBy('athletes.id')
->orderBy('personal_best', 'desc')
->select('athletes.*',DB::raw('MAX(performance) AS personal_best')
->limit(100);
Doc says that we can do max(personal_best) but not sure how to use it with group by.
I'm afraid you can't avoid DB::raw in Query Builder but you can use eloquent model for the same, as answered by Shaielndra Gupta.
For that you can create model and relationship.
1. Create Model:
php artisan make:model Athelete
php artisan make:model Performance
2. Create relationship between Athelete and Perforamnce.
Update Athelete.php
/**
* Get the performances for the Athelete post.
*/
public function performances()
{
return $this->hasMany('App\Performance');
}
3. Get data(didn't verify by myself)
$data = Athelete::with('performances',function ($query) use ($eventId){
$query->max('performance')
$query->where('event_id',$eventId)
$query->orderBy('performance');
})->get();
Reference:
Laravel Model
Laravel Relationship

Answer 3

You can use like below.
$sql1 = "(
SELECT performance
FROM performances
WHERE athletes.id = performances.athlete_id AND performances.event_id = 1
ORDER BY performance DESC
LIMIT 0,1
) AS personal_best";
$sql2 = "SELECT athletes.*,$sql1
FROM athletes
ORDER BY personal_best DESC
Limit 0, 100";
$result = DB::select($sql2);

Answer 4

you can user Eloquent ORM like this
$data = Athelete::with('performances',function ($query) use ($eventId){
$query->max('performance')
$query->where('event_id',$eventId)
$query->orderBy('performance');
})->get()