CREATE TABLE a1 (I1 NUMBER, i2 NUMBER);

INSERT INTO a1 


SELECT 1, 1 FROM dual

UNION 

SELECT 2, 1 FROM dual

;
COMMIT;


CREATE TABLE a2 (i3 NUMBER, d NUMBER);

INSERT INTO a2 
SELECT 1, 100 FROM dual;
COMMIT;

BEGIN
FOR t IN (SELECT
  b.rowid,
a.*, b.* FROM a1 a
INNER JOIN a2 b
ON a.i2 = b.i3)

LOOP
  
dbms_output.put_line (t.d);
UPDATE a2
SET d = 200 WHERE ROWID = t.rowid;
END LOOP;

END;