sql - pl sql. 0 rows merged

Question

I am new to merge so this question may appear too dumb.

I'm running

MERGE INTO regions r
   USING regions_temp t
   ON (r.id_region = t.id_region)
    WHEN NOT MATCHED THEN INSERT (r.id_region, r.region_name)
     VALUES (t.id_region, t.region_name);

Before I run the command the tables have following records (id_region, region_name):

Regions:

1   1   Kiev
2   2   Asia
3   3   Australia
4   4   South America
5   5   Africa

Regions_temp:

1   1   
2   2   Asia
3   3   Australia
4   4   South America

The command runs successfully but on the bottom of the window it says 0 rows merged and no records are merged.

Little help?

Answer 1

merge_insert_clauseのドキュメントによると:

merge_insert_clause は、ON 句の条件が false の場合に、ターゲット テーブルの列に挿入する値を指定します。

のレコードと一致しない のレコードはないため、マージする行はありませんRegions_temp。id_regionRegions

Answer 2

MERGE INTO regions r
   USING regions_temp t
   ON (r.id_region = t.id_region)
    WHEN MATCHED THEN update  set r.region_name =  t.region_name

私が実際に必要としていたものです