# 辅导INFO20003、SQL语言程序辅导

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Database Systems INFO20003 A2 S2 2022 Page 1 of 7
INFO20003 Semester 2, 2022

Assignment 2: SQL
Due: 6:00pm Friday 16th September
Weighting: 10% of your total assessment

Melbourne Touch Rugby Database

Description
The Melbourne Touch Rugby competition is a 6-player-a-side competition for men’s, women’s and
mixed teams (a mixed team has a minimum of 3 women and maximum of 3 men on the field at any
time). Players must be registered with a club to play in the competition and players can only be
registered for one club at a time.
Currently there are 8 rugby clubs participating in the competition, which began in 2020. Each club has
three teams – a men’s team, a women’s team and a mixed team. The men’s competition is known as
the Dewar Shield; the women’s competition is known as the Williams Plate; and the mixed teams
competition is known as the Bingham Trophy.
A season is the set of games played in a competition in a calendar year. Each season consists of rounds
in which every team plays a game.
Even though each game is played by 12 players (6 from each team), a team is not a fixed group of 6
players. The team officials choose 6 players from their club, or possibly even from another club, to play
for that team in a game. As such, the composition of a team may vary from game to game.
If for any reason a team is unable to organise enough players to play a game, that team will forfeit the
game and their opponents will score a “walkover”. A walkover awards 28 points to the team who scores
a walkover and no score is recorded for the team who forfeited. If a game is cancelled (e.g. due to
extreme heat, unsuitable playing pitch), no score is recorded against either team. For the purposes of
considering which games a player has ‘played’ in, forfeit and cancelled games are still counted unless
otherwise specified. A walkover counts as a ‘win’ and ‘loss’ for the corresponding teams, whereas
cancelled games are considered a ‘draw’ (neither team won nor lost) for the purposes of analysis.

Database Systems INFO20003 A2 S2 2022 Page 2 of 7

The Data Model

The physical ER model of Melbourne Touch Rugby database.
Implementation Notes
Each season consists of multiple rounds, the ‘round’ that each game is played in is stored as an attribute
of Game.
A forfeit game (walkover) results in the winning team having a score of 28, and the forfeit team having
a score of ‘NULL’. Cancelled games result in both teams having ‘NULL’ scores.

Database Systems INFO20003 A2 S2 2022 Page 3 of 7
Assignment 2 Setup
A dataset is provided which you may use when developing your solutions. To set up the dataset,
script creates the database tables and populates them with data. Note that this dataset is provided for
you to experiment with, it is not the same dataset as what your queries will be tested against (the schema
will stay the same, but the data itself may be different). This means when designing your queries you
must consider edge cases even if they are not represented in this particular data set. We encourage
you to modify the dataset and add your own data to test edge cases.
The script is designed to run against your account on the Engineering IT server
(info20003db.eng.unimelb.edu.au). If you want to install the schema on your own MySQL Server
installation, uncomment the lines at the beginning of the script.
Note: Do NOT disable only_full_group_by mode when completing this assignment. This mode is
the default, and is turned on in all default installs of MySQL workbench. You can check whether it is
turned on by running the following in workbench:
SELECT @@sql_mode;
The command should return a string containing “ONLY_FULL_GROUP_BY” or “ANSI”. When marking,
our test server WILL have this mode turned on, and if your query fails due to this, you will lose marks.
Run the below command to add the only_full_group_by mode:
SET sql_mode=(SELECT CONCAT(@@sql_mode,',ONLY_FULL_GROUP_BY'))
In this section are listed 10 questions for you to answer. Write one (single) SQL statement per question.
Subqueries and nesting are allowed. You may be penalized for overly complicated SQL statements (e.g.
multiple times longer than required, used vague/poorly named variables, formatting makes it difficult to
read, etc). Unless specified in the question, you do NOT need to sort the results of your query. DO NOT
USE VIEWS (or ‘WITH’ statements/common table expressions) to answer questions.

1. Find the names of all players that are currently in the ‘Melbourne Tigers’ club. Your query should
return data in the form (firstName, lastName) (1 mark)

2. Find the team which has given the most walkovers (forfeited the most number of games).
Assume there are no ties. Your query should return one row of the form (teamName). (1 mark)

3. Find the player that has played in the most clubs over time. You may assume there are no ties.
Don’t count the same club multiple times if a player has played for them multiple times, e.g. if a
player joined and quit the ‘Melbourne Tigers’ several times over the years, all these memberships
only count as having played in one club. Return as (firstName, lastName). (1 mark)

4. Find players that have played more games in 2020 than in 2021. Return as (firstName, lastName,
numGames2020, numGames2021) (2 marks)

Database Systems INFO20003 A2 S2 2022 Page 4 of 7
5. Find the team(s) that ended with the most points scored in the Williams Plate in the 2021 season.
If multiple teams tied for total points, you must display all teams that tied for first. Return as
(teamName, sumOfPoints) (2 marks)

6. Find the names of all women players who have played in the Bingham Trophy, but never the
Williams Plate. Return as (firstName, lastName). (2 marks)

7. For all players that have ever played a game in the league, list the first and most recent club they
ever joined. If these two clubs happen to be the same, return the same name for both. Return
as (firstName, lastName, firstClubName, mostRecentClubName) (2 marks)

8. Find players that have played for every club which has the word ‘Melbourne’ in its name, and
have never joined any of those clubs more than once (i.e. they’ve never left and rejoined any
club with the word ‘Melbourne’ in its name). Return as (firstName, lastName) (3 marks)

9. A player is said to have ‘the magic touch’ when they win (or draw) every game they play in during
a competition season. Find all players who had ‘the magic touch’ in some season, but one or
more of the teams they played for during that season still lost a game during that season (when
they weren’t playing!). Note a ‘competition season’ is specific to a competition, so e.g. the ‘2021
Dewar Shield’ season is distinct from the ‘2021 Bingham Trophy Season’. Return as (firstName,
lastName, competitionName, competitionYear). (3 marks)

10. Find the club that has the largest difference between the win-ratio (ratio of wins/losses; where a
draw is neither a win nor loss) of their best and worst teams in 2021 (across all competitions).
Assume there are no ties. Teams that did not play a game in 2021 should not be considered.
Return as (clubName) (3 marks)

SQL Response Formatting Requirements
To help us mark your assignment queries as quickly/accurately as possible, please ensure that:
Your query returns the projected attributes in the same order as given in the question, and does
“SELECT userId, name …” instead of “SELECT name, userId…” (you can name the
columns using `AS` however you’d like, only the order matters).

FROM users…” instead of “SELECT userId FROM coltonc.users …”.

Ensure that you are using single quotes( ' ) for strings (e.g. …WHERE name = ‘bob’…)and
double quotes ( " ) only for table names (e.g. SELECT name FROM “some table name with
spaces”…). Do NOT use double quotes for strings “…WHERE name = “bob”…”.

Database Systems INFO20003 A2 S2 2022 Page 5 of 7
Submission Instructions
Your submission will be in the form of an SQL script. There is a template file on the LMS, into which you