SQL练习-SQLZOO SQLZOO:The JOIN operation

Posted 2020-12-06 猫山思

game(賽事)

id(編號)	mdate(日期)	stadium(場館)	team1(隊伍1)	team2(隊伍2)
1001	8 June 2012	National Stadium, Warsaw	POL	GRE
1002	8 June 2012	Stadion Miejski (Wroclaw)	RUS	CZE
1003	12 June 2012	Stadion Miejski (Wroclaw)	GRE	CZE
1004	12 June 2012	National Stadium, Warsaw	POL	RUS
...

 

goal(入球)

matchid(賽事編號)	teamid(隊伍編號)	player(入球球員)	gtime(入球時間)
1001	POL	Robert Lewandowski	17
1001	GRE	Dimitris Salpingidis	51
1002	RUS	Alan Dzagoev	15
1001	RUS	Roman Pavlyuchenko	82
...

 

eteam(歐洲隊伍)

id(編號)	teamname(隊名)	coach(教練)
POL	Poland	Franciszek Smuda
RUS	Russia	Dick Advocaat
CZE	Czech Republic	Michal Bilek
GRE	Greece	Fernando Santos
...

 

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1.修改此SQL以列出 賽事編號matchid 和球員名 player ,該球員代表德國隊Germany入球的。要找出德國隊球員，要檢查: teamid = ‘GER‘

SELECT matchid,player FROM goal 
WHERE teamid = ‘GER‘

2.由以上查詢，你可見Lars Bender‘s 於賽事 1012入球。.現在我們想知道此賽事的對賽隊伍是哪一隊。

留意在 goal 表格中的欄位 matchid ，是對應表格game的欄位id。我們可以在表格 game中找出賽事1012的資料。

只顯示賽事1012的 id, stadium, team1, team2

select id,stadium,team1,team2 from game
where id=‘1012‘

3.以下SQL列出每個入球的球員(來自goal表格)和場館名(來自game表格)

修改它來顯示每一個德國入球的球員名，隊伍名，場館和日期。

SELECT player,teamid,stadium,mdate
  FROM game JOIN goal ON (id=matchid)
WHERE teamid=‘GER‘;

4.列出球員名字叫Mario (player LIKE ‘Mario%‘)有入球的 隊伍1 team1, 隊伍2 team2 和 球員名 player

select team1,team2,player from game join goal on(id=matchid)
where player LIKE ‘Mario%‘

5.列出每場球賽中首10分鐘gtime<=10有入球的球員 player, 隊伍teamid, 教練coach, 入球時間gtime

select player,teamid,coach,gtime 
from goal join eteam on teamid=id
where gtime<10

6.列出‘Fernando Santos‘作為隊伍1 team1 的教練的賽事日期，和隊伍名。

SELECT mdate,teamname  
FROM game JOIN eteam ON game.team1=eteam.id  
WHERE eteam.coach=‘Fernando Santos‘

7.列出場館 ‘National Stadium, Warsaw‘的入球球員。

select player from goal join game on game.id=goal.matchid
where game.stadium=‘National Stadium, Warsaw‘