programming-for-dummies

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Database Programming Languages
different operating systems, you can create a Revolution program that can
run on different operating systems (such as Windows, Linux, and Mac OS X).
Database Programming Languages
Programming languages, such as C++, are general-purpose languages because
they can literally be used to create any type of program from operating systems
and word processors to antivirus utilities and video games. However, in
the business world, the most common type of custom programs needed are
those that store and retrieve data, such as invoices, inventory, customer
information, and so on.
Although it’s possible to write a database program in C++, that essentially
doubles the amount of work you need to do.
✦ Write your program’s user interface and commands for manipulating
data.
✦ Write commands to store and retrieve data, essentially creating a
database program from scratch.
Rather than rewrite (and test) your own database program, it’s much easier
just to customize an existing database program instead. Many database programs
include their own programming language. By using a database programming
language, you just have to customize the appearance of the
database program by designing a user interface along with commands for
manipulating data. The database program does all the work of storing,
retrieving, and rearranging the actual data so you can focus on what your
program should do with data and not with the technical details for how it
should store data.
The dBASE programming language
One of the earliest database programming languages for personal computers
was dBASE. By using the dBASE language, you could create a user interface,
write commands for storing data, and write additional commands for retrieving
and manipulating that data.
The following dBASE code creates a simple menu and waits for the user to
type in a choice by choosing a number from 1–6.
SET TALK OFF
USE CUSTOMER.DAT
STORE 0 TO choice
STORE “ No. Name Title Address” TO head
DO WHILE choice 6
ERASE