Answers for "trigger on insert and update IN ORACLE"

oracle insert or update

-- Oracle: Example for Insert or update in t1 from t2 values 
MERGE INTO table1 t1
USING table2 t2
ON (t1.CODE = t2.ID)
WHEN MATCHED THEN
    UPDATE SET t1.COL1 = t2.VALUE1
WHEN NOT MATCHED THEN
    INSERT (CODE, COL1)  VALUES (t2.ID, t2.VALUE1);

sql trigger oracle update

-- SQL Server (update my_table after update on my_table)
CREATE TRIGGER trigger_name ON my_table AFTER UPDATE AS
IF UPDATE (col_name)	-- Optional, for particular column
BEGIN
    UPDATE my_table SET my_col_date = getdate() FROM my_table 
END;
-- Oracle (insert into log table after update on my_table)
CREATE OR REPLACE TRIGGER trigger_name AFTER UPDATE ON my_table
FOR EACH ROW
BEGIN
    INSERT INTO my_log_table (LOG_DATE, ACTION) VALUES (SYSDATE, 'Changed');
END;