SQL Guide : SQL extensions : Triggers
  
Triggers
A trigger is a mechanism for executing a series of SQL statements when a particular action (an INSERT, UPDATE, or DELETE) occurs. The trigger contains a SQL statement that needs to be executed when the trigger is invoked. Triggers are created using solidDB® proprietary stored procedure syntax.
You can create one or more triggers on a table, with each trigger defined to activate on a specific INSERT, UPDATE, or DELETE command. When a user modifies data within the table, the trigger that corresponds to the command is activated.
You can only use inline SQL or stored procedures with triggers. If you use a stored procedure in the trigger, the procedure must be created with the CREATE PROCEDURE command. A procedure invoked from a trigger body can invoke other triggers.
Triggers enable you to:
Implement special integrity constraints, such as checking that certain conditions are maintained, for example, to prevent users from making incorrect or inconsistent data changes.
Take action based on the value of a row before or after modification.
Transfer much of the logic processing to the server, reducing the amount of work that your application needs to do as well as reducing network traffic.
See also
Triggers: Principles of operation
Creating and modifying triggers
Triggers and procedures
Triggers and transactions
Trigger privileges and security
Raising errors from inside triggers
Obtaining trigger information
Trigger parameter settings
Trigger example
SQL extensions