Add CT3531 Database Systems II

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

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+CREATE TABLE teams (
+    team_name VARCHAR(255) NOT NULL,        -- assuming team name is unique
+    home_venue VARCHAR(255) NOT NULL,       -- assuming that two teams could share a home venue (e.g, A teams and B teams)
+    manager VARCHAR(255),                   -- assuming no other information is known/required for managers other than name
+
+    PRIMARY KEY (team_name)
+);
+
+CREATE TABLE players (
+    player_id INT NOT NULL AUTO_INCREMENT,
+    team_name VARCHAR(255) NOT NULL,
+    squad_number INT NOT NULL,              -- assuming squad number is unique within squads
+    player_name VARCHAR(255) NOT NULL,
+
+    PRIMARY KEY (player_id),
+    FOREIGN KEY (team_name) REFERENCES teams(team_name)
+);
+
+CREATE TABLE games (
+    game_id INT NOT NULL AUTO_INCREMENT,    -- no other uniquely identifying information about a game (there could be two otherwise identical games)
+    home_team VARCHAR(255) NOT NULL,        -- venue can be inferred from this
+    away_team VARCHAR(255) NOT NULL,
+    path_to_heap_file VARCHAR(255), 
+
+    PRIMARY KEY (game_id),
+    FOREIGN KEY (home_team) REFERENCES teams(team_name),
+    FOREIGN KEY (away_team) REFERENCES teams(team_name)
+);
+
+-- this table should only be inserted into upon the completion of a game
+CREATE TABLE results (
+    game_id INT NOT NULL,
+    winner VARCHAR(255),                    -- NULL value indicates a draw
+
+    PRIMARY KEY (game_id),
+    FOREIGN KEY (winner) REFERENCES teams(team_name)
+);
+
+-- data redundancy here: players rarely change during match
+CREATE TABLE active_players (
+    active_time TIMESTAMP NOT NULL,
+    game_id INT NOT NULL,
+    player_id INT NOT NULL,
+
+    PRIMARY KEY (active_time, player_id),
+    FOREIGN KEY (game_id) REFERENCES games(game_id),
+    FOREIGN KEY (player_id) REFERENCES players(player_id)
+);
+
+CREATE TABLE substitutions (
+    substitution_time TIMESTAMP NOT NULL,
+    game_id INT NOT NULL,
+    off_player_id INT NOT NULL,
+    on_player_id INT NOT NULL,
+
+    PRIMARY KEY (substitution_time, off_player_id), -- assuming two substitutions could be done at the same time
+    FOREIGN KEY (game_id) REFERENCES games(game_id),
+    FOREIGN KEY (off_player_id) REFERENCES players(player_id),
+    FOREIGN KEY (on_player_id) REFERENCES players(player_id)
+);
+
+CREATE TABLE sendoffs (
+    sendoff_time TIMESTAMP NOT NULL, 
+    game_id INT NOT NULL,
+    player_id INT NOT NULL,
+
+    PRIMARY KEY (sendoff_time, player_id),  -- assuming two sendoffs could be done at the same time - otherwise could just use time
+    FOREIGN KEY (game_id) REFERENCES games(game_id),
+    FOREIGN KEY (player_id) REFERENCES players(player_id)
+);
+
+CREATE TABLE goals (
+    goal_time TIMESTAMP NOT NULL,           -- assuming two goals can't be scored at the same time
+    game_id INT NOT NULL,
+    player_id INT NOT NULL,                 -- cam infer squad number from this 
+    benefitting_team VARCHAR(255) NOT NULL, -- the team to which the points are awarded for this goal
+
+    PRIMARY KEY (goal_time, game_id),
+    FOREIGN KEY (game_id) REFERENCES games(game_id),
+    FOREIGN KEY (player_id) REFERENCES players(player_id),
+    FOREIGN KEY (benefitting_team) REFERENCES teams(team_name)
+);

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

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+-- 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;