football data

This tutorial introducesJOINwhich allows you to use data from two or more tables. The tables contain all matches and goals from UEFA EURO 2012 Football Championship in Poland and Ukraine.

The data is available (mysql format) athttp://sqlzoo.net/euro2012.sql

id	mdate	stadium	team1	team2
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
				...

matchid	teamid	player	gtime
1001	POL	Robert Lewandowski	17
1001	GRE	Dimitris Salpingidis	51
1002	RUS	Alan Dzagoev	15
1002	RUS	Roman Pavlyuchenko	82
			...

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

1.

Show the matchid and player name for all goals scored by Germany. To identify German players, check for:teamid = 'GER'

SELECT matchid, player
FROM goal
WHERE teamid = 
                (
                SELECT id 
                FROM eteam 
                WHERE teamname='Germany'
                );

2.

Show id, stadium, team1, team2 for just game 1012

SELECT id,stadium,team1,team2
FROM game
WHERE id = 1012;

3.

show the player, teamid, stadium and mdate for every German goal.

SELECT player, teamid, stadium, mdate
FROM game 
    JOIN goal ON (id=matchid)
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 
    INNER JOIN goal ON id = matchid
WHERE player LIKE 'Mario%';

5.

Showplayer,teamid,coach,gtimefor all goals scored in the first 10 minutesgtime <= 10

SELECT player, teamid, coach, gtime
FROM goal 
    LEFT JOIN eteam ON teamid = id
WHERE gtime <= 10;

6.

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

SELECT mdate, teamname
FROM game 
    LEFT 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 
    LEFT JOIN game ON matchid = id
WHERE stadium = 'National Stadium, Warsaw';

8.

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

SELECT DISTINCT player
FROM goal 
    LEFT JOIN game 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(gtime)
FROM eteam 
    INNER JOIN goal ON id = teamid
GROUP BY teamname

10.

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

SELECT stadium, COUNT(gtime)
FROM game 
    INNER 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(*)
FROM goal 
    INNER JOIN game 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 matchid, mdate, COUNT(gtime)
FROM goal 
    LEFT JOIN game ON matchid = id
WHERE teamid = 'GER'
GROUP BY matchid, mdate;

13.

List every match with the goals scored by each team as shown. This will use "CASE WHEN" which has not been explained in any previous exercises.

mdate	team1	score1	team2	score2
1 July 2012	ESP	4	ITA	0
10 June 2012	ESP	1	ITA	1
10 June 2012	IRL	1	CRO	3
				...

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.

Solution 1: use subquries (less favorable, less efficient)

To get each score, go to goal table, filter useful rows and count the number.

SELECT 
    mdate,
    team1,
    (SELECT COUNT(gtime) FROM goal WHERE matchid = id AND teamid = team1 ) AS score1,
    team2,
    (SELECT COUNT(gtime) FROM goal WHERE matchid = id AND teamid = team2 ) AS score2
FROM game ;

Solution 2: use CASE operator (more favorable, more efficient)

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, team1, team2
;