Eloquent或Query Builder的Laravel 5子查询

Question

谁能告诉我Laravel 5等效查询(eloquent或query builder )用于以下查询--

select * from questions where id NOT in ( select question_id from answers where student_id=5 ) AND exam_id=4

Answer 1

我自己解决的，

这对我来说非常有效。

$questions= DB:: select ("select * from where id NOT in (select question_id from answers where student_id=5 )$questions= exam_id=4")；