Oracle trigger if inserting or updating
The MERGE statement is designed to combine multiple operations to reduce the complexity of mixed insert and update operations.MERGE allows you to avoid multiple INSERT, UPDATE, and DELETE DML statements by combining the operations into a single statement.-- Creating TRIGGER CREATE OR REPLACE TRIGGER trg_before_emp_update BEFORE UPDATE OF JOB_EXPERIENCE, LAST_APPLIED_DATE on job_openings FOR EACH ROW DECLARE years_since_last_applied number(5); BEGIN years_since_last_applied := -1; IF(: NEW. He is working in a well reputed MNC as an applications Developer with 5 years of experience.LAST_APPLIED_DATE IS NOT NULL) THEN SELECT MONTHS_BETWEEN(TO_DATE(sysdate,'DD-MON-YYYY'), TO_DATE(: NEW. -- Try to update job_experience less than 3 years UPDATE job_openings SET JOB_EXPERIENCE = 2 where APPLICATION_ID = 1; -- error Error report - ORA-20000: Job experience must be more than or equal to 3 years. TRG_BEFORE_EMP_UPDATE", line 21 ORA-04088: error during execution of trigger 'SYSTEM. CREATE TABLE bank_transactions ( TXN_ID number(10) primary key, TXN_NUMBER varchar2(20), PARTY_NAME varchar2(50), TXN_DATE date, CREATED_BY varchar2(20), CREATED_DATE date ); --Creating bank_transactions_audit table. He have good understanding and knowledge of Java, Database, Spring, Hibernate and exploring other technologies related to Software development.ALTER TABLE chicken ADD CONSTRAINT chicken REFegg FOREIGN KEY (e ID) REFERENCES egg(e ID) INITIALLY DEFERRED DEFERRABLE; ALTER TABLE egg ADD CONSTRAINT egg REFchicken FOREIGN KEY (c ID) REFERENCES chicken(c ID) INITIALLY DEFERRED DEFERRABLE; In general, Oracle returns an error message when a constraint is violated.
And that’s when you remember that your table has a for each row after-update trigger that inserts into an audit table, synchronises a mirror table, performs some calculations, updates some other columns, and, probably, pauses to smoke a cigar too. To implement it you write an after-insert trigger on the SALES table. If, for whatever reason, your transaction is rolled back after you’ve inserted 100 rows into SALES, those rows will be erased – but what about the emails? It’s almost as if they’re the apple tree in the middle of Eden, a trap placed there to tempt us to sin. I use them to maintain modified by and modified date columns. So take off that I ♥ DATABASE TRIGGERS t-shirt; let’s set fire to it.If bulk insertion is done or data is inserted from another table mutation will occur.The mutating error is not only encountered during queries, but also for insert, updates and deletes present in the trigger.But, you may be wondering, why are triggers so hated? They can be hundreds of lines long and contain convoluted conditions.Many developers dislike them because they fire silently in the background, seeming to live just beyond the fingertips of their control.