Introduction
The
first step in creating a database is to think about why you need it -- what is
its purpose?
Once you know that, you can begin designing your own database. Ask yourself
questions like: What kinds of information will it store? How will I have to
break that information down, so it can be stored in my database? How will I use
the data once it's in there?
This lesson will walk you through the steps of database design,
using a bookstore scenario. You will determine the purpose
of the database, and plan the tables and fields you will need for a very
simple bookstore database.
The Ready-2-Read Bookstore Scenario
The best way to learn about
designing a database is to jump right into the process. Let's pretend we work
for the Ready-2-Read bookstore and we need to build a database for the store to
use. Let's think about what we might need the database to do for us.
The following diagram shows that we
have customers, and we sell books via orders, both in the
store and online.
The store needs a way to keep track
of these things.
Determine
the Purpose of the Database
The first step of designing a
database is to determine the purpose of the database. What do we need it
to do?
At Ready-2-Read, our customers will
place orders for books. At the very least, we will want our database to track
the books we sell, the customers we sell them to, and the date of
each of the orders.
The database will also be able to
tell us where our customers live when we need to send them books or coupons.
Additionally, we can use it to track our sales or to make a bestseller list to
post in the store.
Plan
Database Tables
Once you have established the
purpose, you can begin brainstorming about how to break the information up into
the tables that your database will need to store the data. Recall that a
table is a collection of records and each record is broken up
into the smallest pieces of needed information, called fields.
Since we are planning a database to
track our customers, the books we have, and the orders our
customers place, we will need a table for each one of these.
TIP: Keep your database usable to others by giving your tables
simple, easy to understand names.
Plan
Table Fields
Once you know what tables you need,
the next step is deciding what fields belong in each table. Remember
that fields are the smallest chunk of information in any record.
Let's look at our Ready-2-Read
bookstore example again. There will be several fields in our Customers
table. We'll obviously want their first name and last name. We'll
also need an address if we need to send the customer his order. Email
will be necessary if we need to contact the customer when there is an issue
with their order.
We will also need several fields in
the Books table. Title and Author make sense for books.
We'll need a Price for each book. Category will help us know what
type of books sell the best, so we can order more books that fit into that
category.
The Orders table will have
fewer fields. We'll need this table to track the Customer who is placing
the order, the Book the customer is ordering, and the Date the
order is placed.
Don't worry if your plan doesn't
include every possible field you may need. Access lets you add fields to tables
any time you think you need another one!
Challenge!
Imagine you want to use a database at your new coffee shop. Plan your database:- What would you want to track with your database?
- What database tables would you need?
- What fields will be in each database table?
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