方法二:连接查询筛选出有效订单记录集合 https://leetcode-cn.com/problems/trips-and-users/solution/san-chong-jie-fa-cong-nan-dao-yi-zong-you-gua-he-n/ 计算订单取消率还可以用avg(Status!='completed'): https://leetcode-cn.com/problems/trips-and-users/solution/ci-ti-bu-nan-wei-fu-za-er-...
点击首页 Explore Coding Questions按钮 或 点击 导航栏 Coding Question 3. 调整过滤器，或者点击下方结...
613.Shortest Distance in a Line (easy) 思路:table内交生成所有可能的点对(应避免重复以提高效率), 然后计算最小距离。 selectmin(ABS(p1.x-p2.x))asshortestfrompointp1joinpointp2onp1.x<p2.x 578.Get Highest Answer Rate Question (medium) 思路: 对于每一个question_id分组,计算出它的Answer rate。
1 SELECT question_id AS survey_log 2 FROM 3 (SELECT 4 question_id, 5 SUM(IF(action='answer',1,0)) as answer_num, 6 SUM(IF(action='show',1,0))as show_num 7 -- SUM(case when action="answer" THEN 1 ELSE 0 END) AS num_answer, 8 -- SUM(case when action="show" THEN 1 ...
使用SQL练习平台:利用如LeetCode这样的在线练习平台,通过解决实际问题来巩固你的SQL技能。 3. 掌握SQL高级功能如聚合、连接和子查询 学习聚合函数:如COUNT()、SUM()、AVG()等,用于对查询结果进行汇总分析。 掌握连接(JOIN)操作:学习不同类型的连接(如INNER JOIN、LEFT JOIN、RIGHT JOIN等),以便从多个表中合并数据...
Structured Query Language (SQL) is the most commonly used programming language for querying and managing data in relational databases. The solution is for the corresponding LeetCode SQL question. - Annahcj/SQL-MySQL-Solutions
Here’s also the code output. 2. Count Student Number in Departments The question from LeetCode asks you the following. “Write an SQL query to report the respective department name and number of students majoring in each department for all departments in theDepartmenttable (even ones with no...
Explanation:The CASE statement is used to categorize employees based on their salary. The result categorizes them as “High”, “Medium”, or “Low”. 19. Find Duplicate Records Question: Write a query to find duplicate email addresses from the users table. Assume the users table has a colu...
qd.difficult_level, COUNT(qpd.question_id) / COUNT(DISTINCT qpd.device_id) FROM question_practice_detail qpd left JOIN user_profile up on up.device_id = qpd.device_id left JOIN question_detail qd on qpd.question_id = qd.question_id WHERE up.university = '山东大学' GROUP BY qd.dif...
题目选自leetcode 上的题库可能不一定都是最优解,答案仅供参考 每道题后面都应相应的难度等级,如果没时间做的话 可以在leetcode 按出题频率刷题 祝大家面试取得好的成绩512. 游戏玩法分析 II难度简单SQL架构Table: Activity+---+---+ | Column Name | Type | +---+---+ | player_id | int | | dev...