The translation units written in SQL-PL are called modules. There are the following different types of modules:
- routines
- functions
- DB procedures
- triggers
- forms
- HELP forms
- menus
Each new module is assigned to a definite program. The program is a collection of modules. A new program is implicitly established with its first module.
A program is executed when one of its modules is called. If no particular module is specified with a program call, SQL-PL assumes that the module with the name START has to be called. The start module can be a routine or a form, but not a menu.