When doing a MERGE in Oracle SQL, how can I update rows that aren't matched in the SOURCE?

Question

I have a main database and a report database, and I need to sync a table from main into report.

However, when an item

Answer 1

The following answer is to merge data into same table

MERGE INTO YOUR_TABLE d
USING (SELECT 1 FROM DUAL) m
    ON ( d.USER_ID = '123' AND d.USER_NAME= 'itszaif') 
WHEN NOT MATCHED THEN
        INSERT ( d.USERS_ID, d.USER_NAME)
        VALUES ('123','itszaif');

This command checks if USER_ID and USER_NAME are matched, if not matched then it will insert.

Answer 2

You can do it with a separate UPDATE statement

UPDATE report.TEST target
SET    is Deleted = 'Y'
WHERE  NOT EXISTS (SELECT 1
                   FROM   main.TEST source
                   WHERE  source.ID = target.ID);

I don't know of any way to integrate this into your MERGE statement.

Answer 3

MERGE INTO target
USING
(
    --Source data
    SELECT id, some_value, 0 deleteMe FROM source
    --And anything that has been deleted from the source
    UNION ALL
    SELECT id, null some_value, 1 deleteMe
    FROM
    (
        SELECT id FROM target
        MINUS
        SELECT id FROM source
    )
) source
   ON (target.ID = source.ID)
WHEN MATCHED THEN
    --Requires a lot of ugly CASE statements, to prevent updating deleted data
    UPDATE SET target.some_value =
        CASE WHEN deleteMe=1 THEN target.some_value ELSE source.some_value end
    ,isDeleted = deleteMe
WHEN NOT MATCHED THEN
    INSERT (id, some_value, isDeleted) VALUES (source.id, source.some_value, 0)

--Test data
create table target as
select 1 ID, 'old value 1' some_value, 0 isDeleted from dual union all
select 2 ID, 'old value 2' some_value, 0 isDeleted from dual;

create table source as
select 1 ID, 'new value 1' some_value, 0 isDeleted from dual union all
select 3 ID, 'new value 3' some_value, 0 isDeleted from dual;


--Results:
select * from target;

ID  SOME_VALUE   ISDELETED
1   new value 1  0
2   old value 2  1
3   new value 3  0

Answer 4

merge into x as target using y as Source on target.ID = Source.ID
when not matched by target then insert
when matched then update
when not matched by source and target.ID is not null then
update whatevercolumn = 'isdeleted' ;