PL/SQL Trigger Structure
Triggers are fired on the tables or views which are in the database. Either table, view ,schema, or a database are the basic requirement to execute a trigger. The trigger is specified first and then the action statement are specified later.
Syntax:
CREATE OR REPLACE TRIGGER trigger_name
BEFORE or AFTER or INSTEAD OF //trigger timings
INSERT or UPDATE or DELETE // Operation to be performed
of column_name
on Table_name
FOR EACH ROW
DECLARE
Declaration section
BEGIN
Execution section
EXCEPTION
Exception section
END;
/
Query operation to be performed i.e INSERT,DELETE,UPDATE.
- CREATE [ OR REPLACE ] TRIGGER trigger_name is used to create a trigger or replace the existing trigger.|
- BEFORE | AFTER | INSTEAD OF specifies trigger timing.
- INSERT | UPDATE | DELETE are the DML operations performed on table or views.
- OF column_name specifies the column that would be updated.
- ON table_name species the table for the operation.
- FOR EACH ROW specify that trigger is executed on each row .
PL/SQL Triggers
PL/SQL stands for Procedural Language/ Structured Query Language. It has block structure programming features.PL/SQL supports SQL queries. It also supports the declaration of the variables, control statements, Functions, Records, Cursor, Procedure, and Triggers.PL/SQL contains a declaration section, execution section, and exception-handling section. Declare and exception handling sections are optional.
Syntax:
Declaration section
BEGIN
Execution section
EXCEPTION
Exception section
END;
Contact Us