This chapter describes the purpose of each component of the CREATE TRIGGER statement, illustrates some uses for triggers, and describes the advantages of using an SPL routine as a triggered action.
In addition, this chapter describes the INSTEAD OF trigger used for views.
An SQL trigger is a mechanism that resides in the database. It is available to any user who has permission to use it. An SQL trigger specifies that when a particular action (an insert, a select, a delete, or an update) occurs on a particular table, the database server should automatically perform one or more additional actions. The additional actions can be INSERT, DELETE, UPDATE, EXECUTE PROCEDURE or EXECUTE FUNCTION statements.
Dynamic Server also supports user-defined routines written in C or in Java as triggered actions.
For information on how to write a C UDR to obtain metadata information about trigger events, see the IBM Informix: DataBlade API Programmer's Guide.
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