Using merge on Oracle example

merge.sql

MERGE INTO <TABLE_NAME> <ALIAS1> USING 
(
  SELECT 
    :COLUMN1 AS COLUMN1
    ,:COLUMN2 AS COLUMN2
    ,:COLUMN3 AS COLUMN3
  FROM DUAL
) <ALIAS2> ON 
(
    --- CONDITION
    <ALIAS2>.COLUMN1 = <ALIAS1>.COLUMN1
    AND <ALIAS2>.COLUMN2 = <ALIAS1>.COLUMN2
)
WHEN MATCHED THEN
  --- UPDATE COMMAND
  UPDATE SET 
  <ALIAS1>.COLUMN3 = <ALIAS2>.COLUMN3
WHEN NOT MATCHED THEN
  --- INSERT COMMAND
  INSERT (COLUMN1, COLUMN2, COLUMN3) 
  VALUES (<ALIAS2>.COLUMN1, <ALIAS2>.COLUMN2, <ALIAS2>.COLUMN3)