programming-for-dummies

Database Programming Languages 79
@ 3,1 SAY “
======================================================”
@ 4,26 SAY “Main Menu”
Book I
Chapter 3
@ 5,1 SAY “
======================================================”
@ 8,26 SAY “1) Display Customer File”
@ 10,26 SAY “2) Display Record”
@ 12,26 SAY “3) Input Record”
@ 14,26 SAY “4) Delete Record”
@ 16,26 SAY “5) Print Customer File”
@ 18,26 SAY “6) Exit”
STORE 0 TO choice
Types of
Programming
Languages
Although the dBASE code may initially look cryptic, you can see how the
dBASE language works like traditional programming languages. The SAY
command simply prints information on-screen much like the BASIC PRINT
command or the C printf command.
At one time, dBASE was so popular that competing companies released similar
dBASE-like languages with names like FoxPro, dBXL, and Clipper. The original
dBASE language and all of its various dialects are referred to under the
generic name of xBASE.
Early versions of the dBASE language were interpreted but later versions
were compiled, allowing programmers to write complete database programs
and sell them to others. The main difference between dBASE and languages
such as C++ is that traditional programming languages can be used to create
anything whereas dBASE is meant just for creating programs that need to
store and retrieve data.
Three popular database programming languages are
✦ Clarion (www.softvelocity.com)
✦ 4 th Dimension (www.4d.com)
✦ Alpha Five (www.alphasoftware.com)
One major drawback of database programming languages is that not as many
programmers know them compared to traditional languages, like C++ and
BASIC. Therefore, if someone writes a custom database application with dBASE,
Clarion, 4 th Dimension, or Alpha Five, nobody else can modify that program
unless they also know dBASE, Clarion, 4 th Dimension, or Alpha Five.