Snippet Name: TRIGGER Example
Description: A trigger is executed implicitly whenever the triggering event happens. The triggering event is either a INSERT, DELETE, or UPDATE command. The timing can be either BEFORE or AFTER.
Also see:
» Trigger sample
» Create trigger in Oracle
Comment: (none)
Language: PL/SQL
Highlight Mode: PLSQL
Last Modified: March 06th, 2009
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-- this example is based on the following two tables:
CREATE TABLE T4 (a INTEGER, b CHAR(10));
CREATE TABLE T5 (c CHAR(10), d INTEGER);
-- create a trigger that may insert a tuple into
-- T5 when a tuple is inserted into T4. Specifically,
-- the trigger checks whether the new tuple has a first
-- component 10 or less, and if so inserts the reverse
-- tuple into T5:
CREATE TRIGGER trig1
AFTER INSERT ON T4
REFERENCING NEW AS newRow
FOR EACH ROW
WHEN (newRow.a <= 10)
BEGIN
INSERT INTO T5 VALUES(:newRow.b, :newRow.a);
END trig1;
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