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POWERBASE TUTORIAL 1
by Laurie Jane Kern
What is a Database?
Put simply, a database is a system of assembling and manipulating data. As with all systems, some are better than others in terms of how efficiently they perform this task.
Look at the following examples of databases:
![]() | A stack of business cards you have yet to put in your address book |
![]() | That list of emergency numbers hanging by the phone (or on the fridge) |
![]() | The spreadsheet that lists all your investments, account numbers, current positions, purchase prices, current prices, date of purchase, total present value and total investment growth |
These are all methods of recording, storing and retrieving information. They RECORD the information you might need, STORE it until you do need it, and RETRIEVE it when that need arises. These are the basic functions of a database.
Of course, each of the above systems presents different ways of and stages in carrying out that function:
![]() | The stack of business cards represents ‘raw’ information – it fulfils the RECORDING function but has not been organised into an efficient STORAGE and RETRIEVAL system |
![]() | The list of emergency numbers RECORDS the information you need, and probably follows some organised system of STORAGE and RETRIEVAL determined by personal priority – either simple alphabetical, or family/work numbers, or utilities/medical/household maintenance, and so on |
![]() | The spreadsheet represents the most organised and developed system of carrying out the functions of a database |
Further, each of the systems presents different DEPTH or DETAIL of information:
![]() | The business cards will probably offer a great deal of information: Personal Name, Job, Company Name, Business Phone, Business Fax, Business Address – and so on |
![]() | The list of emergency numbers will have minimal information: the priority is to link the crisis situation to the telephone number of the person who can help resolve it – the list isn’t very likely to have such things as Business Address, for example |
![]() | The spreadsheet contains all the different kinds of information you need to overview your financial situation in as much detail as you have deemed necessary |
And you can see that the more ORGANISED the system, the more the user of the database has SELECTED the information deemed necessary to make it work efficiently.
So this gives us a perspective on the
governing principles of a database:
![]() | It RECORDS information that the user needs, to the degree of detail that the user feels appropriate |
![]() | It STORES that information record following a system of organisation decided by the user |
![]() | It RETRIEVES and collates that information
record following a system of organisation decided by the user – for example, by
identifying people by job, or location, or telephone number |
Having identifiable general principles encourages a common and distinct vocabulary. Each of the business cards, each row of telephone numbers, and each row in the spreadsheet is called a "record". Every separate piece of information (or data) is called a "field", so that each item of information on the business card belongs to a field, any names alongside the telephone numbers belong to a separate field, any column or cell in the spreadsheet that holds information is a field. Of course, information could be in the form of text or numbers or dates – these different forms are called "data types". I am not going to cover all the data types here as this part could take weeks and I don’t want to put you to sleep!
Suffice it to say that every database (or "dB" for short) contains records which have fields that are filled with data types.
There are many different database programs out there: Sybase, Oracle, SQL Server, Access, Approach, Paradox, dBase and FoxPro – just to name a few. They can do very complex things and it can take weeks through to years to learn all they can do.
The people who maintain these programs within companies are sometimes called DBAs: Database Administrators. They are the gatekeepers of the database, and if the database goes down we all wait for them to fix it!
I do not intend to talk about these programs here, nor will I be comparing PowerBase to them. What I will do is to use the framework offered by Powerbase to teach you the basics of building a database and how to use it.
Why use PowerBase to build a database? Well, if you have found that working with DATA is easy but does not do some things like calculations; or that SHEET does the calculations but won’t sort and find the information you want; then the reason for building your own PowerBase database is perhaps apparent.
Over the next few weeks we are going to build an address book which will evolve into a contact database. Your assignment for now is to look at YOUR current address book and identify those fields which you need to carry the information (data/data type) you want.
I am going to show you how I would do it, but this does not mean that this is the ONLY way. Although people offer general commercial databases, using them is a very PERSONAL thing, geared to individual requirements and preferences.
© LJKern and FoxPop 1999