Oracle Triggers Part 1 in Telugu | Types of Triggers Explained with Examples | Database Concepts
📌 Oracle Triggers Part 1 | Telugu Tutorial
ఈ వీడియోలో Oracle Database లో Triggers అంటే ఏమిటి? ఎప్పుడు వాడాలి? మరియు ఎంత రకాల Triggerలు ఉంటాయి? అన్న అంశాలను సింపుల్గా & రియల్ టైమ్ ఉదాహరణలతో వివరించాను.
#OracleTriggers #OracleInTelugu #PLSQL #DatabaseTutorial #TeluguITTutorials
#OracleTraining #SQLTutorialTelugu #DatabaseConcepts #PLSQLTriggers
Join this channel to get access to perks:
/ @teluguittutorials
Hai I am SrinivasaRao.K,
Notes:
A Trigger is a special PL/SQL block that automatically executes (fires) when certain events occur in a table or database — such as INSERT, UPDATE, DELETE, DDL, or LOGIN events.
Triggers are not called manually — Oracle fires them automatically.
Category Type Description
Based on Event DML Triggers Before/After INSERT, UPDATE, DELETE on a table
DDL Triggers Before/After CREATE, ALTER, DROP
Database Triggers Login/Logout, Startup/Shutdown
Based on Timing BEFORE Trigger Executes before DML operation
AFTER Trigger Executes after DML operation
Based on Row Level ROW Level Trigger Fires for each row affected
STATEMENT Level Trigger Fires once per statement
CREATE TABLE emp_audit (
empno NUMBER,
ename VARCHAR2(30),
action VARCHAR2(10),
action_date DATE
);
AFTER INSERT on EMP
CREATE OR REPLACE TRIGGER trg_emp_insert_audit
AFTER INSERT ON emp
FOR EACH ROW
BEGIN
INSERT INTO emp_audit(empno, ename, action, action_date)
VALUES(:NEW.empno, :NEW.ename, 'INSERT', SYSDATE);
END;
Prevent DELETE of a Manager
BEFORE DELETE Trigger
CREATE OR REPLACE TRIGGER trg_prevent_manager_delete
BEFORE DELETE ON emp
FOR EACH ROW
BEGIN
IF :OLD.job = 'MANAGER' THEN
RAISE_APPLICATION_ERROR(-20001, 'Cannot delete a MANAGER employee!');
END IF;
END;
/
🔍 ఈ వీడియోలో నేర్చుకునే Topics:
✅ Trigger అంటే ఏమిటి?
✅ Triggers ఎందుకు ఉపయోగిస్తారు?
✅ BEFORE vs AFTER Triggers
✅ Statement Level vs Row Level Triggers
✅ Real-Time Use Cases
🎯 ఈ వీడియో Beginners, B.Tech Students, & Job Seekersకి చాలా ఉపయోగపడుతుంది.
👇 Upcoming Parts:
Part 2: Trigger Syntax & Coding Examples
Part 3: Real-Time Project Use Cases
👍 LIKE | 🔁 SHARE | 🔔 SUBSCRIBE చేయడం మర్చిపోవద్దు!