A complete example of using SELECT FOR UPDATE cursors : Cursor for Update « Cursor « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. Cursor
3. Cursor for Update

SQL>
SQL>
SQL> create table product(
  2     product_id number(4)     not null,
  3     product_description varchar2(20) not null
  4  );

Table created.

SQL>
SQL> insert into product values (1,'Java');

1 row created.

SQL> insert into product values (2,'Oracle');

1 row created.

SQL> insert into product values (3,'C#');

1 row created.

SQL> insert into product values (4,'Javascript');

1 row created.

SQL> insert into product values (5,'Python');

1 row created.

SQL>
SQL>
SQL> create table sec_product(
  2     product_id number(4)     not null,
  3     product_description varchar2(20) not null
  4  );

Table created.

SQL>
SQL>
SQL> BEGIN
  2    INSERT INTO sec_product
  3      SELECT * FROM product;
  4    COMMIT;
  5  END;
  6  /

PL/SQL procedure successfully completed.

SQL> DECLARE
  2    CURSOR myCursor IS
  3      SELECT * FROM sec_product FOR UPDATE OF product_description;
  4    v_product_description VARCHAR2(20);
  5  BEGIN
  6    FOR idx IN myCursor LOOP
  7      v_product_description :=UPPER(idx.product_description);
  8      UPDATE sec_product
  9      SET product_description =v_product_description
 10      WHERE CURRENT OF myCursor;
 11    END LOOP;
 12    COMMIT;
 13  END;
 14  /

PL/SQL procedure successfully completed.

SQL>
SQL> drop table product;

Table dropped.

SQL> drop table sec_product;

Table dropped.