Oracle 18c

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CREATE TABLE appdetail (
  id INT,
  location int
);
INSERT INTO appdetail (id) VALUES (1);
1 rows affected

INSERT INTO appdetail (id) VALUES (2);
1 rows affected

INSERT INTO appdetail (id) VALUES (3);
1 rows affected

SELECT * FROM appdetail


ID
LOCATION


1
null

2
null

3
null


CREATE TABLE location (
  id INT,
  appdetail int
);
INSERT INTO location VALUES (1,1);
1 rows affected

INSERT INTO location  VALUES (2,1);
1 rows affected

INSERT INTO location  VALUES (3,3);
1 rows affected

INSERT INTO location  VALUES (4,2);
1 rows affected

CREATE TABLE place (
  id INT,
  name varchar(200)
);
INSERT INTO place  VALUES (1,'New York');
1 rows affected

INSERT INTO place  VALUES (2,'LA');
1 rows affected

CREATE TABLE location_place (
  location int,
  place int
);
INSERT INTO location_place  VALUES (1,1);
1 rows affected

INSERT INTO location_place  VALUES (2,2);
1 rows affected

INSERT INTO location_place  VALUES (3,1);
1 rows affected

INSERT INTO location_place  VALUES (4,2);
1 rows affected

MERGE INTO appdetail AD
USING (
SELECT ID, appdetail, LP.PLACE
  FROM LOCATION L
  JOIN location_place LP
  ON (LP.LOCATION = L.ID) 
) I ON (AD.ID = I.ID)
WHEN MATCHED THEN 
UPDATE SET AD.LOCATION = I.PLACE;
3 rows affected

SELECT * FROM appdetail


ID
LOCATION


1
1

2
2

3
1
ID	LOCATION
1	null
2	null
3	null