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 such a system a relational database (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:

1SELECT 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.