选择Laravel中另一个表中的行数

Question

我不知道如何在Laravel查询构建器中对此进行说明，所以请帮助我。

SELECT A.*, 
       (SELECT COUNT(*) FROM B WHERE B.a_id = A.id) AS TOT,
       (SELECT COUNT(*) FROM C WHERE C.a_id = A.id) AS KOK
FROM A