🗄️ Marathon Race Management Database

A relational database for organising and managing road races — participants, editions, registrations, results, volunteers, and sponsors — implemented in MySQL and Microsoft Access.

Institution: Aristotle University of Thessaloniki (AUTh)
School: Polytechnic School — Department of Mechanical Engineering
Course: Databases
Instructor: Bechtsis Dimitrios
Author: Charitopoulos Kyriazis Semester: 7th Semester, January 2026

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⚙️ Tech Stack

• MySQL — schema definition, data insertion, SQL queries
• Microsoft Access — parallel GUI-based implementation
• SQL — DDL (CREATE, DROP) + DML (INSERT, SELECT)
• InnoDB engine with full referential integrity (FK constraints, CASCADE/RESTRICT)

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🏗️ Database Design

The database models the full lifecycle of a road race series held across Greece. The core design challenge was distinguishing between a race (a permanent, recurring event) and an edition (one annual instance of it) — a Master–Detail pattern that unlocks clean historical tracking.

12 tables across three layers:

Base entities — the standalone objects in the domain:

• symmetexontes — Participants (runners), with status: student / employee / retiree
• diorganotes — Organizers
• agones — Races (e.g. Megas Alexandros, Athens Marathon)
• ekdosi — Editions (annual instances of each race)
• kathgoria_agona — Race categories: 5 km / 10 km / 21 km / 42 km
• xorigoi — Sponsors
• ethelontes — Volunteers

Transactional tables — records that tie participants to events:

• eggrafes — Registrations (participant × edition-category)
• apotelesmata — Results (net finish time per registration)
• pliromes — Payments (amount + method per registration)

Junction tables — resolving M:N relationships:

• ekd_kathg — Edition × Category (with start time per category per edition)
• xorigoi_ekdosi — Sponsor × Edition
• eidi_xorigias — Sponsorship type per sponsor-edition pair
• ethel_ekdosi — Volunteer × Edition (with assigned role)

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📁 Key Files

File	Description
marathon_EN.sql	Full MySQL script: schema + sample data + 3 queries (English comments)
Database_Report_EN.docx	Full project report translated to English
docs/Μαραθωνιος12.docx	Original Greek report (keep in docs/ for reference)
docs/marathon1.accdb	Microsoft Access implementation

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🚀 Quick Start

-- 1. Create and select the database
CREATE DATABASE marathons CHARACTER SET utf8mb4;
USE marathons;

-- 2. Run the full script
SOURCE marathon_EN.sql;

-- 3. Run the three queries (already at the bottom of the script)

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📊 Queries

#	Question	Tables Used
1	Which male participants are students or retirees?	symmetexontes
2	Who ran the 42 km at Megas Alexandros 2025, and what were their times?	symmetexontes, eggrafes, ekd_kathg, apotelesmata
3	Which sponsors supported the Night Half-Marathon, and what did they provide?	xorigoi, xorigoi_ekdosi, ekdosi, agones, eidi_xorigias

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🔑 Design Decisions

Race vs Edition split — separating the permanent race from its annual instance avoids duplicating fixed attributes (name, location, organiser) across every year's data while still supporting full historical records.

Discount logic — the idiotita (status) field on participants encodes eligibility: students and retirees receive a 20% discount, enforced at application level.

Access vs MySQL — the sole structural difference between the two implementations is the eidi_xorigias (sponsorship types) table. Access handles multiple sponsorship types with a built-in lookup field on the junction table; MySQL requires a dedicated child table to avoid normalisation violations.

Faithfulness flags (known quirks in the source):

• pliromes.tropos_plir is declared ENUM('metrita','karta') but the INSERT statements use '1' / '2' — the values will not match the ENUM in a strict MySQL mode. Left as-is from the original.
• eidi_xorigias.eidos_xor similarly has a Greek-literal ENUM but INSERTs use numeric strings. Left as-is.

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👥 Author

Field	Detail
Name	Charitopoulos Kyriazis
University	Aristotle University of Thessaloniki
Department	Mechanical Engineering

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Academic coursework — Aristotle University of Thessaloniki. Not for resubmission in other academic contexts.