Easily into dBase III Plus

96 Pages·1989·4.017 MB·English

by  Peter Gosling (auth.)

Macmillan Modern Office
Easily into
dBASEIIIPLUS
Peter Gosling
M
MACMILLAN
© Peter Gosling 1989
All rights reserved. No reproduction, copy or transmission
of this publication may be made without written permission.
No paragraph of this publication may be reproduced, copied
or transmitted save with written permission or in accordance
with the provisions of the Copyright Act 1956 (as amended),
or under the terms of any licence permitting limited copying
issued by the Copyright Licensing Agency, 33-4 Alfred Place,
London WC1E 7DP.
Any person who does any unauthorised act in relation to
this publication may be liable to criminal prosecution and
civil claims for damages.
First published 1989
Published by
MACMILLAN EDUCATION LID
Houndmills, Basingstoke, Hampshire RG21 2XS
and London
Companies and representatives
throughout the world
British Library Cataloguing in Publication Data
Gosling, P. E. (Peter Edward)
Easily into dBase III plus. - (Macmillan modern
office).
1. Microcomputer systems. Machine-readable files.
Management. Software packages. dBase III Plus
I. Title
005.75'65
ISBN 978-1-349-10475-8 ISBN 978-1-349-10473-4 (eBook)
DOI10.1007/978-1-349-10473-4
Associated practice disk
5¼ inch disk (ISBN 978-0-333-51395-8)
3½ inch microfloppy (ISBN 978-0-333-51396-5)
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D
CONTENTS
Biography v
Acknowledgements vi
About this Book 1
What is a Database? 2
Lesson One 4
Using a database
Types of field
Setting the default drive
Simple commands: LIST, LIST FOR, USE and QUIT
Lesson Two 12
Using logical connectives AND, OR and NOT, the DISPLAY
command, using GOTO, SKIP and BROWSE
Searching for matching strings
Lesson Three 18
Using the ASSIST function
Extracting more information from a database file using
COUNT SUM, AVERAGE
I
The COPY command
Using the REPLACE command
Deleting records from a database file
Using PACK and RECALL
Lesson Four 30
Using LOCATE and CONTINUE, searching for strings
in a database
Creating Query files
Sorting a database, using SORT
Creating index files
Using FIND
Lesson Five 43
Creating a database of your own
APPENDing records to a database
EDITing database fields
LIST STRUCTURE
MODIFY STRUCTURE
Lesson Six 51
Revision lesson and some new dBase III PLUS functions
Lesson Seven 58
Creating data input screens
Using the blackboard
Lesson Eight 63
Printing a report
Creating a report and a report with subtotals
Lesson Nine 74
Creating and using MEMO fields and a MEMO file
Using memory variables
Importing and exporting database files
Creating and printing labels
Use of Function Keys in dBase III PLUS 84
Summary of dBase III PLUS Commands and Functions covered in
this Book 85
Index 89
iv
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0
BIOGRAPHY
Peter Gosling has been working in computer education since the late
1960s. He was a lecturer at Peterborough Technical College until 1981
when he took early retirement having been Principal Lecturer in charge
of the Computer Centre since 1974. In that year he inaugurated the first
educational time-sharing service in Cambridgeshire and taught
Computer Science at GCE A Level as well as working for the Open
University as a part-time Tutor in Mathematics and Computing. For a
number of years he was a member of the joint City and Guilds/NCC
Committee for Computer Programmer Training. Since 1981 he has
devoted his time to writing books on computer programming and
software. These books have been translated into Indonesian and Hebrew
as well as the major European languages. During this time he has also
carried out computer training for a large number of local and national
companies. In 1986 he was joined by his daughter, Joanna, who had
inherited his enthusiasm for the written word and they have already
produced one book jointly for Macmillan Education-Mastering Word
Processing (2nd edition). This partnership is continuing in the current
Macmillan Modern Office series.
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ACKNOWLEDGEMENTS
My thanks to Colin Townley of Windmill Management Training Services
for the production of the databases provided on the practice disk.
dBASE III PLUS is a trademark of Ashton-Tate
Lotus 1-2-3 is a trademark of Lotus Development Corporation
Quattro is a trademark of Borland International
Logistix is a trademark of Grafox Ltd
Vl
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ABOUT THIS BOOK
This book will allow you to become familiar with the main features
of dBASE III PLUS. You will learn how to manipulate the infor
mation stored in a database file, display that information in a
meaningful way using a report and create your own database files.
The disk that accompanies this book contains several specimen
databases for you to use and these will be referred to regularly
throughout the text. The book is divided up into a number of
lessons, each with its objectives clearly stated at the beginning and
with a summary of the topics covered at the end. This means that
you can, if you already have some knowledge of the program, pick
up the points you need to learn at a clearly defined point. When you
have finished this book you will be ready to continue your studies
with the companion to it that takes you into the study of the
dBASE III PLUS programming language so that you will be able to
produce customised programs to help you in your use of database
information.
The first four lessons introduce you to some of the simplest dBASE
III PLUS commands which you will learn to use on one of the
databases supplied on your practice disk. Lesson Five teaches you
how you can create a database of your own and is followed by a
practice lesson to consolidate what you have learned so far. The
remaining lessons introduce you to more features of the program
including the creation of customised screens and reports.
Most of the lessons in this book guide you through the use of
dBASE III PLUS by using the dBASE III PLUS ASSISTANT. This is
a supplied feature that helps you to create commands by choosing
from menus. The ASSISTANT can be switched off if required and
commands keyed in. You will have to do this occasionally in this
book and in every lesson in the companion volume.
When you have completed your studies in these books you will be in
a position to progress to produce more and more sophisticated
database programs and you will be able to use the manual supplied
with the program more efficiently. It is true to say that very few
people use more that about 25 per cent of any computer program
they buy. What you need is a thorough knowledge of the basics of a
program so that you can then proceed to go off into the jungle of
that portion of the program that satisfies your particular
requirements, happy in the knowledge that you can face the more
sophisticated sections with confidence.
A practice disk is available for this book which covers both parts of
the Easily into dBASE III PLUS course. As you will have to modify
the databases supplied on that disk and add extra files we suggest
that you make your own copy of the disk before embarking on the
course. For information regarding the copying of files you should
consult Easily into DOS.
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WHAT IS A DATABASE?
A database is really nothing more than an electronic card index. Not
very many years ago all information was stored on filing cards or in
loose-leaf folders. Information was retrieved by thumbing through
the entire file and extracting the information you required. This
was a long and laborious method of information retrieval. With the
appearance of computers the information previously stored, parti
cularly on the punched cards used in office accounting since the
early twentieth century, could be accessed rapidly and reports on
that information printed out far faster than was ever possible
before. Eventually when large-scale computer storage of data became
practical and cheap it was possible to store very large amounts of
information "on-line", that is, immediately available, rather than
stored away in boxes and filing cabinets.
A database file consists of a number of records - up to a billion in
the case of dBASE III PLUS - each of which consists of a number
of "fields". Each of these fields contains one piece of information; it
might be a surname, part of an address, a date or an amount of
money. The dBASE III PLUS commands allow you to look at this
data, list parts of it, edit it, display it on a screen or print it out on
a printer and create reports by which the data can be listed in a
meaningful manner. In the companion book to this you will learn
how to write programs in the dBASE III programming language so
that you can automate the handling of data, create menus to enable
you to select the tasks you wish to have performed and customise
the screen display so that data entry closely models the filling in of
forms. This means that with a well-written database management
program you can safely leave the use of it to someone who knows
nothing about the way that the program works and can do no
damage to the data contained within the files should incorrect
commands be issued.
The uses to which database management programs such as dBASE III
PLUS can be put are very wide-ranging. Control of a large range of
stock in a warehouse can be exercised using a database program
since it is very easy to produce a figure for the total value of all,
or a section, of the stock, a list of all items dangerously near to the
reorder level or a complete catalogue of everything in stock.
Accounting systems can be written using a database system where
each ledger is a database file. Schools and colleges use database
programs to create timetables and hence can produce room loadings,
staff teaching hours and student/staff ratios together with the mass
of statistics required by the Education Authority. A database
management program such as dBASE III PLUS is another example of
a solution waiting to be given a problem to solve.
On the practice disk are two database files. They relate to a video
club. One database is called VIDEOMEM and contains a list of
members and their names and addresses. The other is called VIDEO
CAT and contains a list of the videos available and their details.
NOTE: The dBASE III PLUS prompt is usually a . and will be
referred to as dot in the text. This can, however, be changed to
whatever you require by examining the CONFIG.DB file and incl
uding a line that says
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--- - - --. . . . . . . . . . . . . . .
- -
PROMPT=. . >
which changes the prompt from a dot to .. >. You can examine the
file by using the DOS TYPE command. See Easily into DOS.
Return Key
In this book, where Return is a separate key depression, it is shown
as Return. Where another key has to be followed by a depression of
the Return key, then the instruction is written for example as
Key in assist (Ret).
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