VilfredSikker / functional-dependency-finder

Simple Python program to find potential functional dependencies from instances of a relation in a MySQL database

functional-dependency-finder

Purpose

Simple CLI-program - written in Python - used to find potential functional dependencies from instances of a relation in a MySQL database.
Useful tool during normalization of a relational database.

Overview

The program connects to a MySQL-database of your choice, and scans each table for functional dependencies by its columns and thereby instances as mentioned.
The results are written to output.

Assumptions about relations and data

• Tables (relations) are considered in isolation (hence no relationships are considered).
• All functional dependencies are found only by checking with one column on each side, such as A -> B.
• If one functional dependency holds for an instance, it's assumed that it hold for all instances of the relation.
  Exception: When an ID-column and a corresponding string-column both determine each other, it's only considered the ID-column determines the string-column, not vice versa.

Usage

To install:

python setup.py install

Run configuration:

usage: main.py [-h] [-u USER] [-p PASSWORD] [-t TABLES [TABLES ...]]
               host database

positional arguments:
  host                  Host running MySQL-database (e.g. localhost)
  database              Name of database

optional arguments:
  -h, --help            show this help message and exit
  -u USER, --user USER  Database user (default: <name of logged-in user>)
  -p PASSWORD, --password PASSWORD
                        Password to database (default: Prompt if not
                        specified.)
  -t TABLES [TABLES ...], --tables TABLES [TABLES ...]
                        Pick which tables to examine (default: all)