HW08: JDBC: Query Anything due Wed 06 Mar 13:00
Allowed and Disallowed Resources
In completing this assignment you MAY use/access the following resources:- Examples and sample code found here: https://josephus.hsutx.edu/classes/db/source/
- The SQL handout provided in class and also available here: https://josephus.hsutx.edu/classes/db/source/sql.pdf
- A text editor (or VSCode) that provides syntax highlighting. You MAY NOT USE an extensions to such editors/IDEs that produce code.
- The phpPgAdmin front end to your personal database (login is here: https://csci.hsutx.edu/phpPgAdmin/
- Video instructions provided in Canvas as part of this course. You MAY NOT USE any other video resources.
- Any handouts provided by the instructor as part of this course.
- Your own course notes
- Your instructor
- Discussions about the assignment with other students as long as you never look at the code produced by another student and you never receive instructions about solving the homework. That is, discussions need to be about concepts and understanding the technologies and not about how to solve the particular problem posed in this assignment.
You may NOT use/access:
- Resources not expressly listed above, including, but not limited to, the following ...
- Source code not provided as part of this assignment. (Obviously, this includes, but is not limited to, source code written by other students whether current or in the past).
- Code-generating tools (of which ChatGPT is one example).
Failure to abide by these guidelines will result in a zero for the assignment and the incident will be reported to the university provost as a violation of the university academic integrity policy. A second incident of academic dishonesty (whether from this course or another computer science course) will result in an F in the course.
Display Any Query
Write a Java program that will connect to the hotel reservations database you created in the previous assignment. The program should provide a method named displayQuery that will accept a query (String) as a parameter and will display the query results formatted so all columns are aligned. Each column should be labeled at the top with the heading name provided in the query result. The columns should be displayed at precisely the width of the longest data value plus a single space.To accomplish this you will need to make two passes through the ResultSet. In the first pass you need to figure out the widest string to be display in each column. On the second pass you need to pad output with spaces to ensure that all items have the same width. REMEMBER: The column name may be the widest value.
As with the in-class assignment you should store your credentials in a file named dbconnect.txt rather than in the Java program itself.
Hints and Suggestions
Access to port 5432 on the csci server is open, but HSU's firewalls prevent off-campus access. You can work on this assignment in a couple of ways:- Do your work on campus (HSUWireless or plugged in to the wall in JB 202).
- Do your work by connecting to the csci.hsutx.edu server using an ssh client. This will require you to learn a text-only editor (such as vim or nano). If you have not worked in this way you need to leave a couple of days just for the purpose of getting proficient in working with files in that environment. This document can help you get started: https://josephus.hsutx.edu/classes/all/remoteaccess/
To determine column header names and other useful metadata about the query result you will make use of a ResultSetMetaData object.
Since you will be making two passes through the ResultSet you need to make the result set scrollable. See the paragraphs of documentation at the top of https://docs.oracle.com/javase/7/docs/api/java/sql/ResultSet.html for information on how to do that.
I recommend (but don't require) that you use an object-oriented design for this program. In particular it would be helpful to have a class to manage a database connection whose constructor will connect to the database. Then the connection object (which will be a classwide attribute) will be available to your displayQuery() method without have to re-establish a connection to the database every time a query is issued.
Submission and Grading
Combine all of your source files (including the dbconnect.txt file) into a single zipped archive called hw8.zip and upload into Canvas before the due date/time.