LeetCode_sql_day18(1841.联赛信息统计)

2024-08-31 01:52

本文主要是介绍LeetCode_sql_day18(1841.联赛信息统计),希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!

描述

表: Teams

+----------------+---------+
| Column Name    | Type    |
+----------------+---------+
| team_id        | int     |
| team_name      | varchar |
+----------------+---------+
team_id 是该表主键.
每一行都包含了一个参加联赛的队伍信息.

表: Matches

+-----------------+---------+
| Column Name     | Type    |
+-----------------+---------+
| home_team_id    | int     |
| away_team_id    | int     |
| home_team_goals | int     |
| away_team_goals | int     |
+-----------------+---------+
(home_team_id, away_team_id) 是该表主键.
每一行包含了一次比赛信息.
home_team_goals 代表主场队得球数.
away_team_goals 代表客场队得球数.
获得球数较多的队伍为胜者队伍.

写一段SQL,用来报告联赛信息. 统计数据应使用已进行的比赛来构建,其中 获胜 球队获得 三分 ,而失败球队获得 零分 。如果 打平 ,两支球队都得 一分 

result 表的每行应包含以下信息:

  • team_name - Teams 表中的队伍名字
  • matches_played - 主场与客场球队进行的比赛次数.
  • points - 球队获得的总分数.
  • goal_for - 球队在所有比赛中获取的总进球数
  • goal_against - 球队在所有比赛中,他的对手球队的所有进球数
  • goal_diff - goal_for - goal_against.

按 points 降序 返回结果表。 如果两队或多队得分相同,则按 goal_diff 降序 排列。 如果仍然存在平局,则以 team_name 按字典顺序 排列它们。

查询的结果格式如下例所示。

示例 1:

输入:
Teams 表:
+---------+-----------+
| team_id | team_name |
+---------+-----------+
| 1       | Ajax      |
| 4       | Dortmund  |
| 6       | Arsenal   |
+---------+-----------+
Matches 表:
+--------------+--------------+-----------------+-----------------+
| home_team_id | away_team_id | home_team_goals | away_team_goals |
+--------------+--------------+-----------------+-----------------+
| 1            | 4            | 0               | 1               |
| 1            | 6            | 3               | 3               |
| 4            | 1            | 5               | 2               |
| 6            | 1            | 0               | 0               |
+--------------+--------------+-----------------+-----------------+
输出:
+-----------+----------------+--------+----------+--------------+-----------+
| team_name | matches_played | points | goal_for | goal_against | goal_diff |
+-----------+----------------+--------+----------+--------------+-----------+
| Dortmund  | 2              | 6      | 6        | 2            | 4         |
| Arsenal   | 2              | 2      | 3        | 3            | 0         |
| Ajax      | 4              | 2      | 5        | 9            | -4        |
+-----------+----------------+--------+----------+--------------+-----------+
解释:
Ajax (team_id=1) 有4场比赛: 2败2平. 总分数 = 0 + 0 + 1 + 1 = 2.
Dortmund (team_id=4) 有2场比赛: 2胜. 总分数 = 3 + 3 = 6.
Arsenal (team_id=6) 有2场比赛: 2平. 总分数 = 1 + 1 = 2.
Dortmund 是积分榜上的第一支球队. Ajax和Arsenal 有同样的分数, 但Arsenal的goal_diff高于Ajax, 所以Arsenal在表中的顺序在Ajaxzhi'qian.

数据准备

Create table If Not Exists Teams (team_id int, team_name varchar(20))
Create table If Not Exists Matches
(home_team_id    int,away_team_id    int,home_team_goals int,away_team_goals int
)
Truncate table Teams ;
insert into Teams (team_id, team_name)
values ('1', 'Ajax')
insert
into Teams (team_id, team_name)
values ('4', 'Dortmund')
insert into Teams (team_id, team_name)
values ('6', 'Arsenal');
Truncate table Matches;
insert into Matches (home_team_id, away_team_id, home_team_goals, away_team_goals)
values ('1', '4', '0', '1')
insert into Matches (home_team_id, away_team_id, home_team_goals, away_team_goals)
values ('1', '6', '3', '3')
insert into Matches (home_team_id, away_team_id, home_team_goals, away_team_goals)
values ('4', '1', '5', '2')
insert into Matches (home_team_id, away_team_id, home_team_goals, away_team_goals)
values ('6', '1', '0', '0');

分析

①先构造出得分情况

select *,casewhen home_team_goals > away_team_goals then 3when home_team_goals = away_team_goals then 1when home_team_goals < away_team_goals then 0end as home_team_points,casewhen home_team_goals < away_team_goals then 3when home_team_goals = away_team_goals then 1when home_team_goals > away_team_goals then 0end as away_team_pointsfrom Matches

②然后分别计算球队比赛次数(主队的次数+客队的次数)、球队总得分(主队时的得分+客队时的得分)、球队总进球数(主队时的总进球数+客队时的总进球数)、对手总进球数(作为主队时对手作为客队的进球数+作为客队时对手作为主队的总进球数)

with t1 as (select *,casewhen home_team_goals > away_team_goals then 3when home_team_goals = away_team_goals then 1when home_team_goals < away_team_goals then 0end as home_team_points,casewhen home_team_goals < away_team_goals then 3when home_team_goals = away_team_goals then 1when home_team_goals > away_team_goals then 0end as away_team_pointsfrom Matches)
select distinct team_name,(select count(1) from t1 where home_team_id = Matches.home_team_id or away_team_id =Matches.home_team_id)  as matches_played,(select sum(home_team_points) from t1 where home_team_id = Matches.home_team_id) +(select sum(away_team_points) from t1 where away_team_id = Matches.home_team_id) as points,(select sum(home_team_goals) from t1 where home_team_id = Matches.home_team_id) +(select sum(away_team_goals) from t1 where away_team_id = Matches.home_team_id) as goal_for,(select sum(away_team_goals) from t1 where home_team_id = Matches.home_team_id) +(select sum(home_team_goals) from t1 where away_team_id = Matches.home_team_id) as goal_against
from matches , teams where matches.home_team_id = teams.team_idunion
select distinct team_name,(select count(1) from t1 where away_team_id = Matches.away_team_id or home_team_id =Matches.away_team_id)  as matches_played,(select ifnull(sum(home_team_points),0 ) from t1 where home_team_id = Matches.away_team_id) +(select ifnull(sum(away_team_points),0) from t1 where away_team_id = Matches.away_team_id) as points,(select ifnull(sum(home_team_goals),0) from t1 where home_team_id = Matches.away_team_id) +(select ifnull(sum(away_team_goals),0) from t1 where away_team_id = Matches.away_team_id) as goal_for,(select ifnull(sum(away_team_goals),0) from t1 where home_team_id = Matches.away_team_id) +(select ifnull(sum(home_team_goals),0) from t1 where away_team_id = Matches.away_team_id) as goal_against
from matches , teams where matches.away_team_id = teams.team_id

③基于上述结果 求goal_diff并且按照题目要求排序

select          team_name,matches_played,points,goal_for,goal_against,(goal_for-goal_against) as goal_diff from t2
order by points desc,goal_diff desc,team_name desc;

图解:

输入
home_team_idaway_team_idhome_team_goalsaway_team_goalshome_team_pointsaway_team_pointsteam_idteam_name
1401034Dortmund
1633111Ajax
4152306Arsenal
610011
分别求出各队作为
主队和客队时的分数、球数
结果
team_namematches_playedpointsgoal_forgoal_against
结果(最终)Dortmund2662
主队的+客队的主队的+客队的主队的+客队的主队的+客队的主队的+客队的Arsenal2233
Ajax4259
在此基础上求出goal_diff
team_namematches_playedpointsgoal_forgoal_againstgoal_diff
Dortmund26624
Arsenal22330
Ajax4259-4

代码

with t1 as (select *,casewhen home_team_goals > away_team_goals then 3when home_team_goals = away_team_goals then 1when home_team_goals < away_team_goals then 0end as home_team_points,casewhen home_team_goals < away_team_goals then 3when home_team_goals = away_team_goals then 1when home_team_goals > away_team_goals then 0end as away_team_pointsfrom Matches)
, t2 as (
select home_team_id,(select count(1) from t1 where home_team_id = Matches.home_team_id or away_team_id =Matches.home_team_id)             as matches_played,(select sum(home_team_points) from t1 where home_team_id = Matches.home_team_id) +(select sum(away_team_points) from t1 where away_team_id = Matches.home_team_id) as points,(select sum(home_team_goals) from t1 where home_team_id = Matches.home_team_id) +(select sum(away_team_goals) from t1 where away_team_id = Matches.home_team_id) as goal_for,(select sum(away_team_goals) from t1 where home_team_id = Matches.home_team_id) +(select sum(home_team_goals) from t1 where away_team_id = Matches.home_team_id) as goal_against
#         goal_for-goal_against as goal_diff
from matchesunion all
(select away_team_id,(select count(1) from t1 where away_team_id = Matches.away_team_id or home_team_id =Matches.away_team_id)             as matches_played,(select sum(away_team_points) from t1 where away_team_id = Matches.away_team_id) +(select sum(home_team_points) from t1 where home_team_id = Matches.away_team_id) as points,(select sum(home_team_goals) from t1 where home_team_id = Matches.away_team_id) +(select sum(away_team_goals) from t1 where away_team_id = Matches.away_team_id) as goal_for,(select sum(away_team_goals) from t1 where home_team_id = Matches.away_team_id) +(select sum(home_team_goals) from t1 where away_team_id = Matches.away_team_id) as goal_againstfrom Matches)
)select distinct (select team_name from teams where team_id=t2.home_team_id)team_name,matches_played,points,goal_for,goal_against,(goal_for-goal_against) as goal_diff from t2
order by points desc,goal_diff desc,team_name;

总结

最后要考虑到有的球队只有客队场 所以使用union 既要关联到主队id又要关联到客队id

这篇关于LeetCode_sql_day18(1841.联赛信息统计)的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!



http://www.chinasem.cn/article/1122552

相关文章

Java通过驱动包(jar包)连接MySQL数据库的步骤总结及验证方式

《Java通过驱动包(jar包)连接MySQL数据库的步骤总结及验证方式》本文详细介绍如何使用Java通过JDBC连接MySQL数据库,包括下载驱动、配置Eclipse环境、检测数据库连接等关键步骤,... 目录一、下载驱动包二、放jar包三、检测数据库连接JavaJava 如何使用 JDBC 连接 mys

SQL中如何添加数据(常见方法及示例)

《SQL中如何添加数据(常见方法及示例)》SQL全称为StructuredQueryLanguage,是一种用于管理关系数据库的标准编程语言,下面给大家介绍SQL中如何添加数据,感兴趣的朋友一起看看吧... 目录在mysql中,有多种方法可以添加数据。以下是一些常见的方法及其示例。1. 使用INSERT I

Qt使用QSqlDatabase连接MySQL实现增删改查功能

《Qt使用QSqlDatabase连接MySQL实现增删改查功能》这篇文章主要为大家详细介绍了Qt如何使用QSqlDatabase连接MySQL实现增删改查功能,文中的示例代码讲解详细,感兴趣的小伙伴... 目录一、创建数据表二、连接mysql数据库三、封装成一个完整的轻量级 ORM 风格类3.1 表结构

MySQL 中的 CAST 函数详解及常见用法

《MySQL中的CAST函数详解及常见用法》CAST函数是MySQL中用于数据类型转换的重要函数,它允许你将一个值从一种数据类型转换为另一种数据类型,本文给大家介绍MySQL中的CAST... 目录mysql 中的 CAST 函数详解一、基本语法二、支持的数据类型三、常见用法示例1. 字符串转数字2. 数字

Mysql实现范围分区表(新增、删除、重组、查看)

《Mysql实现范围分区表(新增、删除、重组、查看)》MySQL分区表的四种类型(范围、哈希、列表、键值),主要介绍了范围分区的创建、查询、添加、删除及重组织操作,具有一定的参考价值,感兴趣的可以了解... 目录一、mysql分区表分类二、范围分区(Range Partitioning1、新建分区表:2、分

MySQL 定时新增分区的实现示例

《MySQL定时新增分区的实现示例》本文主要介绍了通过存储过程和定时任务实现MySQL分区的自动创建,解决大数据量下手动维护的繁琐问题,具有一定的参考价值,感兴趣的可以了解一下... mysql创建好分区之后,有时候会需要自动创建分区。比如,一些表数据量非常大,有些数据是热点数据,按照日期分区MululbU

SQL Server配置管理器无法打开的四种解决方法

《SQLServer配置管理器无法打开的四种解决方法》本文总结了SQLServer配置管理器无法打开的四种解决方法,文中通过图文示例介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的... 目录方法一:桌面图标进入方法二:运行窗口进入检查版本号对照表php方法三:查找文件路径方法四:检查 S

MySQL 删除数据详解(最新整理)

《MySQL删除数据详解(最新整理)》:本文主要介绍MySQL删除数据的相关知识,本文通过实例代码给大家介绍的非常详细,对大家的学习或工作具有一定的参考借鉴价值,需要的朋友参考下吧... 目录一、前言二、mysql 中的三种删除方式1.DELETE语句✅ 基本语法: 示例:2.TRUNCATE语句✅ 基本语

MySQL中查找重复值的实现

《MySQL中查找重复值的实现》查找重复值是一项常见需求,比如在数据清理、数据分析、数据质量检查等场景下,我们常常需要找出表中某列或多列的重复值,具有一定的参考价值,感兴趣的可以了解一下... 目录技术背景实现步骤方法一:使用GROUP BY和HAVING子句方法二:仅返回重复值方法三:返回完整记录方法四:

从入门到精通MySQL联合查询

《从入门到精通MySQL联合查询》:本文主要介绍从入门到精通MySQL联合查询,本文通过实例代码给大家介绍的非常详细,需要的朋友可以参考下... 目录摘要1. 多表联合查询时mysql内部原理2. 内连接3. 外连接4. 自连接5. 子查询6. 合并查询7. 插入查询结果摘要前面我们学习了数据库设计时要满