COMP9120辅导、辅导Python讲解编程
School of Computer Science
COMP9120 Database Management Systems
Assignment 2: Database Application Development
Group Assignment (12%)
Introduction
The objectives of this assignment are to gain practical experience in interacting with a relational database
management system using an Application Programming Interface (API) (Python DB-API). This assignment
additionally provides an opportunity to use more advanced features of a database such as functions.
This is a group assignment for teams of about 3 members, and it is assumed that you will continue in your
Assignment 1 group. You should inform the unit coordinator as soon as possible if you wish to change groups.
Please also keep an eye on your email and any announcements that may be made on Ed.
Submission Details
The final submission of your database application is due at 11:59pm on Friday 20th May. You should submit
the items for submission (detailed below) via Canvas.
Items for submission
Please submit your solution to Assignment 2 in the ’Assignment’ section of the unit’s Canvas site by the
deadline, including EXACTLY THREE files:
An assignment coversheet as a PDF document (.pdf file suffix) which is available for download from this
link on Canvas.
A SQL file (WSASchema.sql) containing the SQL statements necessary to generate the database
schema and sample data. This should contain the original schema and insert SQL statements, and any
changes or additions you may have made.
A Python file (database.py) containing the Python code you have written to access the database.
Task 1: The Western Sydney Airport (WSA) System
In this assignment, you will be working with the WSA system which is currently under development. The
system still requires work in numerous areas, including interaction with the database. Your main task in this
assignment is to handle requests for reads and writes to the database coming from the user interface (UI).
We first describe the main features that the WSA system should include from a UI perspective, and then
discuss where the majority of your database code needs to be implemented.
Logging In
The first form a user is presented with when starting the WSA system is Login, as shown in Figure 1. This
feature is still under development and currently requires that an employee (technician or test engineer) enters
his/her username and password to be validated prior to successfully log in to the system. Security features
such as password encryption/hashing will be implemented at a later stage (and is out of scope for this
assignment). Once logged in, the user is taken to the Civil Aviation Safety Authority (CASA) Test Events List
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page to view their associated tests for the various aircrafts.
Figure 1 – Login form
Viewing Test Events List
Once a user has logged in, they are shown a list of all their associated test events, as shown below in Figure
2. This list must be ordered such that aircrafts needing test to be performed appear at the top. The list is also
sorted by test date in ascending order. Each test event has a test date, aircraft registration number, status,
assigned technician, and test engineer. A test event is associated with an employee if the appropriate
employee is allocated as either the technician or test engineer to conduct the CASA compliance test.
Figure 2 – Viewing Test Events List
Finding Test Events
A user can search through all test events by entering a word or phrase (a ‘keyword’) in the field next to the
Find button, as shown in Figure 3, and then clicking on Find. When such a keyword is specified, then only
test events including this word or phrase in their status description, aircraft registration number, or employee
names will be retrieved and shown on the list. The search must ignore case sensitivity. For example, given
the search keyword ‘in progress’, Find will return all test events that include the keyword ‘in progress’ in their
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status description, aircraft registration number, or employee names. Searching with a blank/empty keyword
field will show all of the logged in user’s associated test events. Any search results returned must be
ordered such that aircrafts needing test to be performed appear at the top, and by test date in ascending
order.
Figure 3 – Finding Test Events
Adding a Test Event
Users may also add a new test event by clicking on the Add Test tab in the title bar, entering test details
such as test date and aircraft registration number, in the popup dialog that appears, and then clicking on
Add Test button, as shown in Figure 4.
Figure 4 – Adding a Test Event
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Updating a Test Event
Users can also update a test event by modifying data in the test event details screen as shown in Figure 5,
and clicking on Update Test button. You can access this update screen by clicking on a test event from the
list of test events in the Tests tab.
Figure 5 – Updating a Test Event
Database Interaction Code
The files that are needed for the Python version of assignment are as follows:
1. WSASchema.sql: a file which contains SQL statements you need to run to create and initialise
the WSA system database, before starting the application
https://canvas.sydney.edu.au/files/23473879/download?download_frd=1
2. Assignment2_PythonSkeleton.zip: a zip file encapsulating the Python project for the
WSA system https://canvas.sydney.edu.au/files/23484341/download?download_frd=1
To inspect the WSA system code, you need to unzip the ZIP archive first, which will create a folder that
includes the name Assignment2_PythonSkeleton. If you experience any difficulties installing and
exploring the project, ask your tutor or lecturer for assistance.
The skeleton code uses a number of Python modules to implement a simple browser-based GUI for the WSA
system. The main modules are the Flask framework for the GUI and the psycopg2 module for the PostgreSQL
database access. Similar to tutorial 8, you will need to install the Psycopg2 module and the Flask module.
The skeleton code follows the structure described below:
The main program starts in the main.py file. You need to use the correct username/password details
as specified in tutorial 8, and then implement the missing database access functions – including any
necessary SQL code statements required – in the data layer database.py.
The presentation layer is done via a simple HTML interface that can be accessed from a web browser.
The corresponding page templates are located in the templates/ subdirectory, their CSS style
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file is static/css.
The transition between the different GUI pages and the initialisation of the Flask framework is done in
the routes.py file. It currently just invokes the pages, but there is no further business logic
implemented yet.
You can run the code by running “python main.py”. This starts a local web server and prints out some
debug messages in the terminal. Please note that, to terminate the application, you will need to stop the local
web server which is running in the background.
Task 2: Functions Implementation
Core Functionality
In this assignment, you are provided with a Python skeleton project that must serve as the starting point for
your assignment. Your task is to provide a complete implementation for the file database.py, as well as
make any modifications necessary to the database schema (i.e., WSASchema.sql). Specifically, you need
to modify and complete these five functions:
1. checkEmpCredentials (for login)
2. findTestsByEmployee (for viewing test events list)
3. findTestsByCriteria (for finding test events)
4. addTest (for adding test event)
5. updateTest (for updating test event)
Note that, for each function, the corresponding action should be implemented by issuing SQL queries to the
database management system. If you directly output and/or manipulate the result without issuing SQL queries,
you are considered as cheating, and you will get zero point for the assignment.
Marking
This assignment is worth 12% of your final grade for the unit of study. Your group’s submission will be
marked in line with the rubric that follows.
Group member participation
If members of your group do not contribute sufficiently, you should alert the unit coordinator as soon
as possible. The course instructor has the discretion to scale the group’s mark for each member as follows: