Alina_0229

题解

/ 注册

全部文章 / 题解（共80篇）

题解 | #插入记录（二）#

insert into exam_record_before_2021(uid,exam_id,start_time,submit_time,score) select uid,exam_id,start_time,submit_time,score from exam_record where Y...

Mysql

2022-03-14

0 204

题解 | #插入记录（一）#

insert into exam_record(uid,exam_id,start_time,submit_time,score) VALUES (1001,9001,'2021-09-01 22:11:12','2021-09-01 23:01:12',90), (1002,9002,'2021-...

Mysql

2022-03-12

0 203

题解 | #返回每个顾客不同订单的总金额#

select Orders.cust_id,sum(item_price * quantity) total_ordered from OrderItems right join Orders on OrderItems.order_num = Orders.order_num group by c...

Mysql

2022-03-12

1 333

题解 | #浙大不同难度题目的正确率#

select qd.difficult_level,count(if(qp.result="right",1,null)) / count(qp.question_id) correct_rate from user_profile up join question_practice_detail ...

Mysql

2022-03-12

0 245

题解 | #插入记录（一）#

insert into exam_record (id,uid,exam_id,start_time,submit_time,score) values(1,1001,9001,"2021-9-1 22:11:12","2021-9-1 23:01:12",90) insert into exam_...

Mysql

2022-03-11

0 183

题解 | #纠错4#

SELECT cust_name, cust_contact, cust_email FROM Customers UNION SELECT cust_name, cust_contact, cust_email FROM Customers WHERE cust_state = 'IL' and ...

Mysql

2022-03-10

0 280

题解 | #列出供应商及其可供产品的数量#

select Vendors.vend_id,count(Products.prod_id) prod_id from Vendors left join Products on Vendors.vend_id = Products.vend_id group by Vendors.vend_id ...

Mysql

2022-03-10

0 303

题解 | #返回产品名称和每一项产品的总订单数#

select Products.prod_name,count(OrderItems.order_num) from Products left join OrderItems on Products.prod_id = OrderItems.prod_id group by Products.pr...

Mysql

2022-03-10

0 236

题解 | #返回产品名称和与之相关的订单号#

select Products.prod_name,OrderItems.order_num from Products left join OrderItems on Products.prod_id = OrderItems.prod_id order by Products.prod_name...

Mysql

2022-03-10

0 354

题解 | #检索每个顾客的名称和所有的订单号（二）#

select Customers.cust_name,Orders.order_num from Customers left join Orders on Customers.cust_id = Orders.cust_id order by Customers.cust_name select ...

Mysql

2022-03-10

0 250