力扣sql简单篇练习(十八)

力扣sql简单篇练习(十八)

1 报告的记录

1.1 题目内容

1.1.1 基本题目信息

1.1.2 示例输入输出

1.2 示例sql语句

SELECT extra report_reason,count(distinct post_id) report_count
FROM Actions
WHERE action_date=DATE_SUB('2019-07-05',interval 1 day) AND extra IS NOT NULL AND action='report'
GROUP BY extra

1.3 运行截图

2 即时事物配送|

2.1.1 基本题目信息

2.1.2 示例输入输出

2.2 示例sql语句

# 总订单数量可以在SELECT子句中用子查询查询出来
SELECT ROUND(count(delivery_id)/(SELECT count(delivery_id) FROM Delivery)*100,2) immediate_percentage
FROM Delivery
WHERE order_date=customer_pref_delivery_date

2.3 运行截图

3 重新格式化部门表

3.1 题目内容

3.1.1 基本题目信息

3.1.2 示例输入输出

3.2 示例sql语句

# 多列变成多行 聚合函数加上group by处理
#存在可能id值的某些月份的收入为null,这个需要考虑一下的
SELECT id,
      sum(IF(month='Jan',revenue,null)) Jan_Revenue,sum(IF(month='Feb',revenue,null)) Feb_Revenue,
      sum(IF(month='Mar',revenue,null)) Mar_Revenue,sum(IF(month='Apr',revenue,null)) Apr_Revenue,
      sum(IF(month='May',revenue,null)) May_Revenue,sum(IF(month='Jun',revenue,null)) Jun_Revenue,
      sum(IF(month='Jul',revenue,null)) Jul_Revenue,sum(IF(month='Aug',revenue,null)) Aug_Revenue,
      sum(IF(month='Sep',revenue,null)) Sep_Revenue,sum(IF(month='Oct',revenue,null)) Oct_Revenue,
      sum(IF(month='Nov',revenue,null)) Nov_Revenue,sum(IF(month='Dec',revenue,null)) Dec_Revenue
FROM  Department
GROUP BY id

3.3 运行截图