php - Database Exception in yii2

Solution:

For multiple data in select you can use array. You also need a space before AS:

 $totalah = Sah::find()
  ->select(['mhs', 'SUM(IF(status_kehadiran = 1,status_kehadiran , 0)) AS K3211335'])
  ->where([
       'kode_mk'=> 'K3211335'
  ])
  ->groupBy('mhs')
  ->all();

Solution:

If I undestand you purpose, you sum status_kehadiran when status_kehadiran = 1, why you don't just SUM status_kehadiran where status_kehadiran = 1

$totalah = Sah::find()
  ->select(['mhs', 'SUM(status_kehadiran) AS K3211335'])
  ->where([
       'kode_mk'=> 'K3211335',
       'status_kehadiran' => 1
  ])
  ->groupBy('mhs')
  ->all();