MEGER sentence in oracle

MEGE Sentence

This oracle tutorial explains how to use the oralce MEGER sentence with syntax and samples.

Description

The MEGE sentence aim to reduce operator sentences.

Syntax

The syntax for the  MEGE  sentence is

MEGE <hint>
INTO <TABLE_NAME>
USING <table_view_or_query>
ON (<condition>)
WHERE MATCH THEN <update_clause>
DELETE <where_clause>
WHERE NOT MATCHED THEN <insert_clause>
[LOG ERRORS <log_errors_clause> <reject limit <integer | unlimited>];

Example

CREATE TABLE dept60_bonuses(
employee_id NUMBER,
bouns_amt NUMBER
);
INSERT INTO dept60_bonuses VALUES(103,0);
INSERT INTO dept60_bonuses VALUES(104,0);
INSERT INTO dept60_bonuses VALUES(105,0);
commit;

SELECT employee_id,last_name,salary
FROM employees
WHERE department_id=60;

MERGE INTO dept60_bonuses b
USING(
   SELECT employee_id,salary,department_id
   FROM employees
   WHERE department_id=60) e
ON (b.employee_id=e.employee_id)
WHEN MATCHED THEN
UPDATE SET b.bouns_amt=e.salary*2
WHERE b.bouns_amt=0
DELETE WHERE (e.salary>7500)
WHEN NOT MATCHED THEN
INSERT (b.employee_id,b.bouns_amt)
VALUES (e.employee_id,e.salary*0.1)
WHERE (e.salary<7500);