Add CT3531 Database Systems II

third/semester1/CT3532: Database Systems II/assignments/assignment1/queries.sql

@@ -0,0 +1,36 @@
+-- 1. List all players playing for a given team
+-- SELECT * FROM active_players JOIN players ON active_players.player_id = players.player_id WHERE team_name = "<insert team name here>" AND time = CURRENT_TIMESTAMP;
+SELECT player_name FROM players WHERE team_name = "man u";
+
+-- 2. List all players who have scored in a given game
+SELECT player_id FROM goals WHERE game_id = "<insert game ID here>";
+SELECT player_name FROM goals JOIN players ON goals.player_id = players.player_id WHERE game_id = 1;
+
+-- 3. List the top five goal scorers in the league
+SELECT player_id, COUNT(*) as goals_scored FROM goals GROUP BY player_id ORDER BY goals_scored DESC LIMIT 5;
+SELECT player_id, COUNT(*) as goals_scored FROM goals GROUP BY player_id ORDER BY goals_scored DESC LIMIT 5;
+SELECT
+    player_name, COUNT(*) as goals_scored
+FROM
+    goals INNER JOIN players ON goals.player_id = players.player_id
+GROUP BY players.player_id
+ORDER BY goals_scored DESC
+LIMIT 5;
+
+-- 4. List all teams and the amounts of points that they have so far
+-- drawback: adding up each time, costly if this is a common query
+SELECT
+    teams.team_name,
+    SUM(
+        CASE
+            WHEN results.winner = teams.team_name THEN 3
+            WHEN results.winner IS NULL THEN 1
+            ELSE 0
+        END
+    ) AS total_points
+FROM
+    teams
+LEFT JOIN games ON teams.team_name = games.home_team OR teams.team_name = games.away_team
+LEFT JOIN results ON games.game_id = results.game_id
+GROUP BY
+    teams.team_name;