INGRES ABF can be used to build the "Hierarchy" of menus, reports, applications and standard INGRES facilities that form a specified application. An ABF application may include frames of the following three types:-
In order to build an application you will need to:
You do not need to create an application for each FRAME that you define. A single application may contain several frames of different type and specification.
When developing applications you will need to refer to the INGRES ABF Users Guide & INGRES 4GL Language Reference Manual.
The ABF guide APP C, contains all of the 4GL code for the Project Management Application which is based on the DEMO database. This can give you significant help when it comes to writing your own 4GL code. (This code is also available by inspecting the DEMO example itself).
Applications By Forms (ABF) exercise - do this now.
INGRES 4GL is an event-driven language. That is, a sequence of 4GL statements will be executed depending on the choices of the user. We are interested in four types of activations available in INGRES 4GL, which are:-
Depending upon the required functionality the code triggered off by an activation can include Declaration Statements, Database Access Statements, Forms-Control & Flow-Control statements and Inquiry Statements.
The following exercise is designed to give you an insight into the way the activiations and 4GL statements available in INGRES can be used to build user-specified applications. It will be seen that SQL statements are used, embedded within the 4GL to access the database.
The exercise also demonstrates the use of the unloadtable statement.