public function createBillets($students, $refer) { $students->each(function ($student) use($refer) { $exists = $student->whereHas('billets', function ($q) use($refer, $student) { $q->where('refer', $refer)->where('student_id', $student->id)->select('id'); })->exists(); if (!$exists) { $this->createBillet($student, $refer); } }); }