皮皮学，免费搜题
登录
搜题
【单选题】
处理( )的电子电路是数字电路。A.
交流电压信号
B.
时间和幅值上连续的信号
C.
时间和幅值上离散的信号
D.
无法确定
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【简答题】音频信号的编码
【多选题】在bookshop数据库中有5 个表，这五个表的结构描述见“实验数据库描述”。其中员工表employee(emp_no,emp_name,sex,dept,title,date_hired,birthday,salary,telephone,addr)，客户表customer(cust_name,receiver,tel_no,cust_Addr)，图书表books(book_no,book_na...
A.
update sales set total_amt=total_amt*1.1 where cust_name in (select cust_name from customer where cust_name like '刘%')
B.
update sales set total_amt=total_amt*1.1 where cust_name = (select cust_name from customer where cust_name like '刘%')
C.
update sales set total_amt=total_amt*1.1 from customer,sales where sales.cust_name=customer.cust_name and customer.cust_name like '刘%'
D.
update sales set total_amt=total_amt*1.1 where exists (select * from customer where sales.cust_name=customer.cust_name and customer.cust_name like '刘%')
【多选题】在图书销售数据库bookshop中有5 个表,这五个表的结构描述见“实验数据库描述”。其中员工表employee(emp_no,emp_name,sex,dept,title,date_hired,birthday,salary,telephone,addr),客户表customer(cust_name,receiver,tel_no,cust_Addr),图书表books(book_no,boo...
A.
update sales set total_amt=total_amt*1.1 where cust_name in (select cust_name from customer where cust_name like '刘%')
B.
update sales set total_amt=total_amt*1.1 where exists (select * from customer where sales.cust_name=customer.cust_name and customer.cust_name like '刘%')
C.
update sales set total_amt=total_amt*1.1 where cust_name = (select cust_name from customer where cust_name like '刘%')
D.
update sales set total_amt=total_amt*1.1 from customer,sales where sales.cust_name=customer.cust_name and customer.cust_name like '刘%'
【简答题】统计每位客户订购的每种图书的总数量及平均单价，并按客户名，图书号从小到大排列。使用以下SQL语句实现：select customer.cust_name,sale_item.book_no ,sum(qty)总数量,sum(qty*unit_price)/sum(qty) 平均单价from sales,customer,sale_itemwhere sales.cust_name=customer...
相关题目：