Oracle 11g Release 2

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CREATE TABLE Individuals ( person_id INT, first_name VARCHAR2(100), last_name VARCHAR2(100));
INSERT INTO Individuals
SELECT 100,'John','Doe' FROM dual UNION ALL
SELECT 101,'John','Doe' FROM dual; 
2 rows affected

CREATE TABLE Cases ( person_id INT, case_number INT );
INSERT INTO Cases
SELECT 100,12345 FROM dual UNION ALL
SELECT 101,6789  FROM dual; 
2 rows affected

CREATE TABLE matter_person ( person_id INT, matter_number VARCHAR2(10) );
INSERT INTO matter_person
SELECT 100,'123abc' FROM dual UNION ALL
SELECT 101,'456def' FROM dual;
2 rows affected

DECLARE
  v_pid_new individuals.person_id%type := 100;
  v_pid_old individuals.person_id%type := 101;  
BEGIN
  FOR c IN ( SELECT * FROM user_tab_cols WHERE column_name = 'PERSON_ID' )
  LOOP
   DBMS_OUTPUT.PUT_LINE( c.table_name ); 
   IF c.table_name = 'INDIVIDUALS' THEN
     EXECUTE IMMEDIATE 'DELETE '||c.table_name||' WHERE person_id=:pido' USING v_pid_old;     
   ELSE
     EXECUTE IMMEDIATE 'UPDATE '||c.table_name||' SET person_id=:pidn WHERE person_id=:pido' USING v_pid_new,v_pid_old;  
   END IF;  
     COMMIT;
  END LOOP; 
END;
/
1 rows affected

dbms_output:
CASES
INDIVIDUALS
MATTER_PERSON

SELECT * FROM Individuals;


PERSON_ID
FIRST_NAME
LAST_NAME


100
John
Doe


SELECT * FROM Cases;


PERSON_ID
CASE_NUMBER


100
12345

100
6789


SELECT * FROM matter_person;


PERSON_ID
MATTER_NUMBER


100
123abc

100
456def