SQLZOO The JOIN operation 문제 풀이

1. Modify it to show the matchid and player name for all goals scored by Germany. To identify German players, check for: teamid = 'GER

 

SELECT matchid,player
FROM game join goal on matchid=id
WHERE teamid='GER'

 

2. Notice in the that the column matchid in the goal table corresponds to the id column in the game table. We can look up information about game 1012 by finding that row in the game table Show id, stadium, team1, team2 for just game 1012

SELECT DISTINCT id,stadium,team1,team2
FROM game join goal on matchid=id
where matchid=1012

 

3. Modify it to show the player, teamid, stadium and mdate for every German goal

SELECT  player, teamid, stadium,mdate
FROM game join goal on matchid=id
where teamid='GER'

 

4. Show the team1, team2 and player for every goal scored by a player called Mario player LIKE 'Mario%'

SELECT  team1,team2,player
FROM game join goal on matchid=id
where player like 'Mario%'

 

5. Show player, teamid, coach, gtime for all goals scored in the first 10 minutes gtime<=10

SELECT player, teamid, coach,gtime
FROM goal join eteam on teamid=id
 WHERE gtime<=10

 

6. List the dates of the matches and the name of the team in which 'Fernando Santos' was the team1 coach.

SELECT mdate,teamname
FROM game join eteam on team1=eteam.id
 WHERE coach='Fernando Santos'

 

7. List the player for every goal scored in a game where the stadium was 'National Stadium, Warsaw'

SELECT player
FROM goal
  JOIN game ON (id=matchid AND stadium = 'National Stadium, Warsaw')

 

8. Instead show the name of all players who scored a goal against Germany.

SELECT distinct player
FROM game
  JOIN goal ON matchid = id
WHERE ((team1='GER' OR team2='GER') AND teamid != 'GER')

 

9. Show teamname and the total number of goals scored.

SELECT teamname, count(teamname)
FROM eteam JOIN goal ON id=teamid
group by teamname

 

10. Show the stadium and the number of goals scored in each stadium.

SELECT stadium, count(stadium)
  FROM game JOIN goal ON id=matchid
group by stadium

 

11. For every match involving 'POL', show the matchid, date and the number of goals scored.

SELECT matchid,mdate, count(mdate)
  FROM game JOIN goal ON matchid = id 
 WHERE (team1 = 'POL' OR team2 = 'POL')
group by matchid,mdate

 

12. For every match where 'GER' scored, show matchid, match date and the number of goals scored by 'GER'

SELECT id, mdate, COUNT(player)
FROM game JOIN goal ON (id=matchid AND (team1 = 'GER' OR team2 = 'GER') AND teamid='GER')
GROUP BY id, mdate

 

13. Notice in the query given every goal is listed. If it was a team1 goal then a 1 appears in score1, otherwise there is a 0. You could SUM this column to get a count of the goals scored by team1. Sort your result by mdate, matchid, team1 and team2.

SELECT mdate
	,team1
	,SUM(CASE WHEN teamid = team1 THEN 1 ELSE 0 END) AS score1
	, team2
	,SUM(CASE WHEN teamid = team2 THEN 1 ELSE 0 END) AS score2 
FROM game LEFT JOIN goal ON (id = matchid)
GROUP BY mdate,team1,team2
ORDER BY mdate, matchid, team1, team2