用两个不同的列laravel连接同一张表

Question

I try these code in MySQl:

SELECT      
     A.*, 
     B.name,
     C.name
FROM 
     eventlog_tbl as A
     LEFT JOIN users B ON A.byuser=B.email 
     LEFT JOIN users C ON A.affectiveuser=C.email;

I try these in Laravel

return DB::table('eventlog_tbl')
            ->leftjoin('users', 'users.email', '=', 'eventlog_tbl.byuser')
            ->leftjoin('users', 'users.email', '=', 'eventlog_tbl.affectiveuser')
            ->select('eventlog_tbl.*','users.name','users.name')
            ->get();

How can i convert it to Laravel?

Answer 1

Try below code:

$res =  DB::table('eventlog_tbl')
        ->leftjoin('users AS A', 'A.email', '=', 'eventlog_tbl.byuser')
        ->leftjoin('users AS B', 'B.email', '=', 'eventlog_tbl.affectiveuser')
        ->select('eventlog_tbl.*','A.name as byuser_name','B.name as affectiveuser_name')
        ->get();

    print_r($res);

Answer 2

This is your query written using the Laravel query builder.

$events = DB::table('eventlog_tbl')
    ->select('eventlog_tbl.*', 'users_1.name', 'users_2.name')
    ->leftJoin('users AS users_1', 'users_1.email', '=', 'eventlog_tbl.byuser')
    ->leftJoin('users AS users_2', 'users_2.email', '=', 'eventlog_tbl.affectiveuser')
    ->get();

Edit:

$events = DB::table('eventlog_tbl')
    ->select('eventlog_tbl.*', 'users_1.name AS user_1', 'users_2.name AS user_2')
    ->leftJoin('users AS users_1', 'users_1.email', '=', 'eventlog_tbl.byuser')
    ->leftJoin('users AS users_2', 'users_2.email', '=', 'eventlog_tbl.affectiveuser')
    ->get();

The problem is that both name columns are called the same thing. As per the accepted answer, these will need to be aliased differently too.

Answer 3

Why don't you convert this to use relationships? I have probably got the relationships wrong, something like this:

class EventLog extends Model
{
    public function byUser()
    {
        return $this->hasOne(User::class, 'byuser', 'id');
    }

    public function affectiveUser()
    {
        return $this->hasOne(User::class, 'affectiveuser', 'id');
    }
}

And then

$event_log = EventLog::with(['byUser', 'affectiveUser')->all();


foreach ($event_log as $item) {
    echo $item->byUser->email();
}