A project from the module Object Oriented Programming with Java, part of my MSc course 2023-2024.

A database server written from scratch. The database persists when the server goes down. Data is stored in tab-separated files ("tables") within folders ("databases"). The server can interpret SQL-like commands, for example:

CREATE DATABASE markbook;
[OK]

USE markbook;
[OK]

CREATE TABLE marks (name, mark, pass);
[OK]

INSERT INTO marks VALUES ('Simon', 65, TRUE);
[OK]

INSERT INTO marks VALUES ('Sion', 55, TRUE);

INSERT INTO marks VALUES ('Rob', 35, FALSE);

INSERT INTO marks VALUES ('Chris', 70, TRUE);

CREATE TABLE coursework (task, submission);

INSERT INTO coursework VALUES ('OXO', 3);

INSERT INTO coursework VALUES ('DB', 1);

INSERT INTO coursework VALUES ('OXO', 4);

INSERT INTO coursework VALUES ('STAG', 2);

SELECT * FROM marks WHERE name == 'Chris';
[OK]
4 Chris 70 TRUE

JOIN coursework AND marks ON submission AND id;
[OK]
id coursework.task marks.name marks.mark marks.pass
1 OXO Rob 35 FALSE
2 DB Simon 65 TRUE
3 OXO Chris 20 FALSE
4 STAG Sion 55 TRUE

ALTER TABLE marks ADD age;
[OK]

DELETE FROM marks WHERE name != 'Bob';
[OK]

UPDATE marks SET mark = 75 WHERE name == 'Chris';
[OK]

DROP TABLE marks;
[OK]

DROP DATABASE markbook;
[OK]

For the specification of the query language, see BNF.txt and for examples of a sequence of commands, see example-transcript.pdf.