哈喽.沃德
哈喽.沃德
全部文章
分类
题解(4)
归档
标签
去牛客网
登录
/
注册
哈喽.沃德的博客
全部文章
(共4篇)
题解 | #纠错4#
SELECT cust_name, cust_contact, cust_email FROM Customers WHERE cust_state = 'MI' UNION SELECT cust_name, cust_contact, cust_email FRO...
Mysql
2022-05-16
0
288
题解 | #提取博客URL中的用户名#
从最后一个 / 处截取字符串 substring_index函数 select us.device_id,substring_index(us.blog_url,'/',-1) as user_name from user_submit us 替换掉前面的字符串 replace()函数 ...
Mysql
2022-04-29
13
521
题解 | #浙江大学用户题目回答情况#
select substring_index(us.profile,',',-1) as gender,count(*) number from user_submit us group by gender; 函数:根据index截取字符串 substring_index(str,del...
Mysql
2022-04-29
0
255
题解 | #浙江大学用户题目回答情况#
select date_format(qpd.date,'%d') as day,count(*) as question_cnt from question_practice_detail qpd where date_format(qpd.date,'%Y-%m') = '2...
Mysql
2022-04-29
1
289