Validating Parameters in Oracle Reports using PL/SQL

Parameters can be populated and validated using various srw pl/sql triggers.

The following gives examples of: 

Validation trigger in parameter form 
 
Before parameter form trigger
 
After parameter form trigger
 
Before report trigger   
 

Examples of validation triggers on the property sheet for parameter 

PARAM_SAL. 

Query: select * from emp where sal > :PARAM_SAL 

These functions validate just this one trigger. The validation occurs when 

the user hits next field after inputting a value for the parameter. When the 

trigger is failed it returns to the parameter form.