What
is a Database?
Databases
are basically programs that store lists of data in a systematic
order. Telephone directories, filing cabinets, bus timetables
or card files are all common examples of databases. Microsoft
Access, the software referred to in this section, is a database
program and is part of the Microsoft Office Professional software
suite. Other popular packages are dBase, FoxPro, Paradox and Approach.
Organisation
of a Database Program
There is no point in just adding data to a file unless it is stored
in a systematic order. So that the information you want to store
can be accessed easily, we need to use common structures as shown
below:
-
Tables store information in files. The data is displayed in
columns (fields) and rows (records).
- Fields
store information, such as surname, price, cost, address, etc.
-
Records are categories of information concerning a person, company,
event etc. For example: James, Lotus Ltd., West Road, etc.
Programs
like Access can store huge amounts of data, and sort them in any
order you choose. It is also easy to add, amend or delete data.
You will notice when you use a database that alterations are instantly
made to the file removing the need to save your work at the end
of a session.
Below
is an example of a database containing a table with 5 fields and
3 records:
Displaying
Data
The are many ways in which data can be shown on the computer screen.
It could be in the form of a vertical list or table displaying
all the records (first illustration below) or one record showing
all the fields (second illustration below). A single list of data
is referred to as a 'flat file' database. Some more powerful programs
are said to be 'relational'. This means that they can link up
with other files - ie. word processing and spreadsheets. Access,
in common with other large database packages, has a common language
so that it can import files from other databases.
Contents:
Databases
Skill
Check: Databases
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