在where子句中使用函数：

Student::whereIn('family_id', function($query) {
   $query->select('family_id')
     ->from(with(new Students)->getTable())
     ->groupBy('family_id')
     ->havingRaw('COUNT(1) > 1')
})->get();

$query = DB::select("SELECT * 
FROM Student
WHERE family_id IN (SELECT family_id 
                    FROM students 
                    GROUP BY family_id 
                    HAVING COUNT(1)>1)
ORDER BY family_id")

基于laravel文档