/* 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 = 'GER';


/* 2 ---------------------------------------------------------------------------

   From the previous query you can see that Lars Bender's scored a goal in game
   1012. Now we want to know what teams were playing in that match.

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


/* 3 ---------------------------------------------------------------------------

   You can combine the two steps into a single query with a JOIN.

   SELECT *
   FROM game JOIN goal ON (id=matchid)

   The FROM clause says to merge data from the goal table with that from the
   game table. The ON says how to figure out which rows in game go with which
   rows in goal - the id from goal must match matchid from game. (If we wanted
   to be more clear/specific we could say ON (game.id=goal.matchid)

   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 ---------------------------------------------------------------------------

   Use the same JOIN as in the previous question.

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

 */

SELECT team1,
       team2,
       player
  FROM game JOIN goal ON id = matchid
 WHERE player LIKE 'Mario%';


/* 5 ---------------------------------------------------------------------------

   The table eteam gives details of every national team including the coach. You
   can JOIN goal to eteam using the phrase goal JOIN eteam on teamid=id

   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 ---------------------------------------------------------------------------

   To JOIN game with eteam you could use either game JOIN eteam ON
   (team1=eteam.id) or game JOIN eteam ON (team2=eteam.id)

   Notice that because id is a column name in both game and eteam you must
   specify eteam.id instead of just id

   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 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 matchid = id
 WHERE stadium = 'National Stadium, Warsaw';


/* 8 ---------------------------------------------------------------------------

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

 */

SELECT DISTINCT player
  FROM game JOIN goal ON matchid = id
 WHERE teamid <> 'GER' AND
       (team1 = 'GER' OR team2 = 'GER');


/* 9 ---------------------------------------------------------------------------

   Show teamname and the total number of goals scored

 */

SELECT teamname,
       COUNT(*)
  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(*)
  FROM game JOIN goal ON matchid = id
 GROUP BY stadium;


/* 11 --------------------------------------------------------------------------

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

 */

SELECT matchid,
       mdate,
       COUNT(*)
  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 matchid,
       mdate,
       COUNT(*)
  FROM game JOIN goal 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.

   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 matchid = id
 GROUP BY mdate,
	  team1,
	  team2
 ORDER BY mdate,
	  matchid,
	  team1,
	  team2;
