create table (
id int,
user_name varchar2(20),
salary int,
emp_deptno int
);

insert into emp (ID, USER_NAME, SALARY, EMP_DEPTNO) values (1, 'Zhangsan', 1700, 10);insert into emp (ID, USER_NAME, SALARY, EMP_DEPTNO) values (2, 'Lisi', 4300, 20);insert into emp (ID, USER_NAME, SALARY, EMP_DEPTNO) values (3, 'Wangwu', 6600, 30);insert into emp (ID, USER_NAME, SALARY, EMP_DEPTNO) values (4, 'Qianliu', 5100, 20);insert into emp (ID, USER_NAME, SALARY, EMP_DEPTNO) values (5, 'Chenqi', 7500, 30);commit;

declarev_increment int;v_deptno    int;cursor emp_cursor isselect * from emp;
beginfor i_emp in emp_cursor loopv_deptno := i_emp.emp_deptno;case v_deptnowhen 10 thenv_increment := 100;when 20 thenv_increment := 200;when 30 thenv_increment := 300;elsev_increment := 400;end case;update empset salary = salary + v_incrementwhere emp_deptno = v_deptno;end loop;
end;
/select * from emp;

declarev_increment int;v_deptno    int;cursor emp_cursor isselect distinct emp_deptno from emp;
beginfor i_emp in emp_cursor loopv_deptno := i_emp.emp_deptno;case v_deptnowhen 10 thenv_increment := 100;when 20 thenv_increment := 200;when 30 thenv_increment := 300;elsev_increment := 400;end case;update empset salary = salary + v_incrementwhere emp_deptno = v_deptno;end loop;
end;
/select * from emp;

declarev_increment int;v_deptno    int;cursor emp_cursor isselect *  from emp for update of salary;
beginfor i_emp in emp_cursor loopv_deptno := i_emp.emp_deptno;case v_deptnowhen 10 thenv_increment := 100;when 20 thenv_increment := 200;when 30 thenv_increment := 300;elsev_increment := 400;end case;update empset salary = salary + v_incrementwhere current of emp_cursor;end loop;
end;
/select * from emp;