题目内容:
现有订单表orders, 包含数据如下表。若查询既订购了产品P01,又订购了产品P02的顾客编号,可以执行以下()sql语句。 cid (顾客编号) Pid (产品编号) C01 P01 C01 P02 C02 P01 C03 P02A.select distinct(cid) from orders o1 where o1.pid in (.p01.,.p02.)
B.select distinct(cid) from orders o1,orders o2 where o1.pid=.p01. and o2.pid=.p02. and o1.cid=o2.cid
C.select distinct(cid) from orders o1 where pid=.p01. and cid in (select cid from orders where pid =.p02.)
D.select distinct(cid) from orders o1,orders o2 where o1.pid=.p01. and o2.pid=.p02.
参考答案: