HP 3000 Manuals HP 3000 Manuals
Chapter 4 Constraints, Procedures, and Rules In addition to the basic tables and indexes in a DBEnvironment, ALLBASE/SQL lets you create database objects known as constraints, procedures, and rules, which provide for a high degree of data consistency and integrity inside the DBEnvironment without the need for extensive application programming. Constraints define conditions on the rows of a table; procedures define sequences of SQL statements that can be stored in the DBEnvironment and applied as a group either through rules or through execution by specific users; and rules let you define complex relationships among tables by tying specific procedures to particular kinds of data manipulation on tables. Together, these tools let you store many of your organization's business rules in the DBEnvironment itself, reducing the need for application code. This chapter presents the following topics: * Using Integrity Constraints * Using Procedures * Using Rules