| Lesson 2 || What is a database? |
| Objective || Describe what a database is. |
What is a Database?
Here is the simple definition of a database: a database is an organized list of related information.
As I said in the introduction, you probably use some sort of database every day. It may not be on a computer, but if it is an organized list of related data, then it is a database.
A phone book is one example of a database. A phone book holds a list of names, addresses, and phone numbers. The data is related because you are storing the same type of information for each person (i.e. name, address, and phone number). Many databases are kept on computers for the flexibility it gives you to sort, filter, and organize data. As you already know, Access is a popular database application, and many people just beginning to delve into the world of databases start with Access,
because it is relatively easy to use, but also provides flexibility.
The SlideShow below shows some examples of databases that you may use every day.
Access stores data in tables that look much the same as worksheets but are designed for complex querying in relation to data stored in other tables and locations.
If your data needs to be stored in more than one table, then you need a relational database. Each table is basically a description of a type of data (such as orders for a customer).
If you require a relational database, you have identified a one-to-many relationship in your data. For example, if you have a customer order database, one table will contain customer names and another will contain their orders.
A single customer can have many orders. Additionally, you might want to have another table for order details since each order can have multiple line items. Relational data is best stored in Access.
Do you notice this direct correlation between the size of your data and the challenge you have in organizing it effectively? The more data you have, the more likely you are to store it in multiple tables in Access.
To help manage your data and keep it accurate, Access and Excel provide you with unique identifiers. In Access, a primary key (an icon in the shape of a key visible in Design view of your table) uniquely identifies each record.