题目介绍: 查询球队积分 team-scores-in-football-tournament
难度中等
SQL架构
Table:
Teams
+---------------+----------+
| Column Name | Type |
+---------------+----------+
| team_id | int |
| team_name | varchar |
+---------------+----------+
此表的主键是 team_id,表中的每一行都代表一支独立足球队。
Table:
Matches
+---------------+---------+
| Column Name | Type |
+---------------+---------+
| match_id | int |
| host_team | int |
| guest_team | int |
| host_goals | int |
| guest_goals | int |
+---------------+---------+
此表的主键是 match_id,表中的每一行都代表一场已结束的比赛,比赛的主客队分别由它们自己的 id 表示,他们的进球由 host_goals 和 guest_goals 分别表示。
积分规则如下:
写出一条SQL语句以查询每个队的 team_id,team_name 和 num_points。结果根据 num_points 降序排序,如果有两队积分相同,那么这两队按 team_id 升序排序。
查询结果格式如下:
``` Teams table: +-----------+--------------+ | team_id | team_name | +-----------+--------------+ | 10 | Leetcode FC | | 20 | NewYork FC | | 30 | Atlanta FC | | 40 | Chicago FC | | 50 | Toronto FC | +-----------+--------------+
Matches table: +------------+--------------+---------------+-------------+--------------+ | match_id | host_team | guest_team | host_goals | guest_goals | +------------+--------------+---------------+-------------+--------------+ | 1 | 10 | 20 | 3 | 0 | | 2 | 30 | 10 | 2 | 2 | | 3 | 10 | 50 | 5 | 1 | | 4 | 20 | 30 | 1 | 0 | | 5 | 50 | 30 | 1 | 0 | +------------+--------------+---------------+-------------+--------------+
Result table: +------------+--------------+---------------+ | team_id | team_name | num_points | +------------+--------------+---------------+ | 10 | Leetcode FC | 7 | | 20 | NewYork FC | 3 | | 50 | Toronto FC | 3 | | 30 | Atlanta FC | 1 | | 40 | Chicago FC | 0 | +------------+--------------+---------------+ ```
sql
select team_id , team_name ,sum(
if(team_id = host_team && host_goals>guest_goals ,3,0)+
if(team_id = host_team && host_goals=guest_goals,1,0)+
if(team_id = guest_team && host_goals=guest_goals,1,0)+
if(team_id = guest_team && host_goals<guest_goals ,3,0)
)num_points
from Teams t left join Matches m
on t.team_id =m.host_team or t.team_id =m.guest_team
group by team_id ,team_name
order by num_points desc,team_id