Application Development with Harbour/Understanding Workareas
What is a workarea in the Clipper/Harbour language? Edit
Let us for a moment think back at the old times when commonly used computers had no mouse and GUI. Nevertheless, if we wanted to use several tables for a task, we had to use some way to tell the computer which tables he should consider. Let us take for example a library. Oversimplifying, we need to use at least three tables to manage it (one for the books, one for the customers and one for the loans).
We might issue these commands:
SELECT 1 USE Books SELECT 2 USE Customers SELECT 3 USE Loans SELECT Books
We might visualize the result as the three windows in the picture below:
Here the command SELECT works like clicking on a window to activate it, and the workareas themselves look like windows having a number (the workarea number) and a name (the workarea alias).