The Gate is open - summary

Congratulations, @name! You have passed through the Gate of the Great Library. Here is what you already know:

What you have learned

• A database is an organized collection of data - like our Library full of shelves.
• Table = shelf, row = scroll, column = field.
• The primary key (

  id

  ) uniquely identifies every row.
• MySQL is an RDBMS system working in the client-server model.
• SQL is the Library's command language.
• SELECT ... FROM ... retrieves data from a table;

  *

  means all columns.
• We list columns separated by a comma, and we end every query with a semicolon ";".
• We write keywords in UPPERCASE by convention; a comment begins with

  --

  .

Our Library - map of the shelves

Throughout the journey we will work on the same

biblioteka

database:

| Table | What it stores | |-------|----------------| |

ksiazki

| titles, year of publication, price, availability | |

autorzy

| the creators of the books | |

kategorie

| thematic sections | |

czytelnicy

| people enrolled in the Library | |

wypozyczenia

| borrowing history |

What's next?

In the next location - the Catalog Hall - you will learn to search the shelves: filter scrolls (

WHERE

), sort them (

ORDER BY

) and limit the number of results (

LIMIT

). Onward, deeper into the Library!