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What is a Table?

A table is a list of one type of thing, with columns chosen first and one row per item.

A database holds related facts. The most basic unit inside it is the table . A table is a subject-based list arranged in rows and columns . You choose the columns first. Each row is one more of the same kind of thing.

Riverside Public Library needs a list of members and a list of books. Those are two different kinds of thing. Each gets its own table.

Every row is a member. 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.

Every row is a book. 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.

One type of thing per table

Do not put members and books in the same list. Then one column means two different things. On one row, the extra column holds 07700 900 123. On the next row, it holds A. Morgan. The City column is empty for books because a book has no city.

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.

Two tables fix the problem. Members holds people. Books holds titles. Every column has one job. This rule is not library-only. A cinema keeps films in one list and tickets in another. A shop keeps products and sales in separate tables. One table, one type of thing.

Two piles, two tables

The desk already kept members and books apart. The database should do the same.

Practice

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Which of these should be its own table?

Select every set that is one kind of thing.

Which sentence best describes a table?

Why is the mixed list a problem?

Members

Books