RDBMS and MySQL - the heart of the Library

A relational database

Our Library is not one giant pile of scrolls. It is organized - a separate shelf for books, another for authors, another for readers. And between them run cross-references (relations): a book scroll points to which shelf holds the description of its author.

We call this way of storing data a relational database, and the program that manages it an RDBMS (Relational Database Management System). Data is split into tables that connect to one another through relations.

What is MySQL?

MySQL is one of the world's most popular RDBMS systems - software that:

• stores your tables and keeps them safe,
• understands commands in the SQL language,
• serves many readers (clients) at once.

MySQL works in a client-server model:

• The server is the Library itself - it guards the shelves and carries out commands.
• The client is a scribe (e.g. a program or the mysql console) that sends queries and receives answers.

SQL - the language of the Library

SQL (Structured Query Language) is the language in which we give the Library orders:

SELECT tytul FROM ksiazki;

This sentence means: "Show me the titles of all books on the ksiazki shelf". As simple as an order given to a librarian!

A bit of history

MySQL was created in 1995 by the Swedish company MySQL AB. The name joins the co-founder's daughter's name - My - with the word SQL. Today it powers a huge part of the internet: from small blogs to Facebook and YouTube.