First of all, I have to make certain assumptions about you as a learner. I assume, for example, that:
- You already have experience of using a version of Microsoft Windows.
- You have previously used another software package e.g. Word or Excel.
What Is A Database?
An electronic database is a collection of data (information) on a particular topic. It is organised and stored in such a way that data can be retrieved easily and quickly when we ask the database specific questions. As you will see later, it is much more flexible than “manual” systems which use paper and filing cabinets.
Here are a few examples of database topics:
- Personal and financial details of bank customers
- The stock held by a supermarket
- Details of sports club members
- A catalogue of all your music CDs
When we create a new database, it is very important to plan carefully the structure
that we need to suit the kind of data we want to store and retrieve.
We shall design our database as a TABLE. Before we do so, you should know the following terms:
DATABASE
A collection of data on one particular topic.
e.g. a database in a video shop, giving details of all the videos available for sale.
Each new database must have its own unique FILENAME.
TABLE
A grid consisting of columns and rows.
Each Table must have its own TABLE NAME.
One database may have a number of tables in it.
A table is often referred to by professional database designers as an ENTITY. Although these pages will still refer to tables as tables, be aware of this term!
FIELD
A column of the Table, containing one category of data.
For example, it can be the Title of a film or the name of its Director or the Price of the video.
Each field must have a heading called a FIELD NAME.
A Table may have any number of Fields.
DATA TYPE
The kind of Data contained in a Field.
The data types may be Text, Number or Currency.
Each Field must contain a single Data Type.
RECORD
A row of the Table, in which we put the actual data
For example, this could be the details of one film in all the Fields (columns)
Each record is unique. Although some records may have some data in common (e.g. two films may have the same Director), no two records will have the same data in all fields.
