Introduction

This course teaches the ideas behind a database: facts, tables, keys, relationships, rules, and asking questions of stored records.

You do not need Microsoft Access, SQL, or programming for these pages. Software comes later, in its own course, once the ideas are solid.

Read at your own pace. Each lesson is one page. Use Next at the bottom when you are ready.

By the last lesson you should be able to look at a messy list of facts and explain, in ordinary English:

• which facts belong together
• why members and books need two tables
• how a number on one row links to a row in another table
• what goes wrong when the same fact is copied in three places
• how to check a design before anyone opens the software

You will not be asked to memorise product menus. The test is whether you can explain the idea with an example.

Every lesson is one page of short sections and tables.

A term box gives the accepted wording, the same idea in plain English, and how it shows up at the library. Those boxes quote a published source.

Near the end of a lesson you will often get a short Try this check. Answer from what you have just read.

Riverside Public Library in York must remember people who join, books it owns, and which copy is out on loan. That mix of people, things, and events is enough to teach every idea in this course.

Desk staff copy membership forms onto cards. This is a small teaching example. A real library may have thousands of members, books, and loans. We use a few rows so you can see the pattern clearly.

A hospital, a school, or a shop would work as well. We stay with one library so each lesson can build on the last.

The sidebar lists every lesson, grouped by topic. This page is the map. The next page starts Data.

A browser and time to read. Nothing is installed in this course.

If a word is new, keep going. The next section or the glossary at the end will give it a meaning. The next page starts the subject: what counts as data.