oracle 的游标(cursor )的用法。

906vlxtey0

游标
游标分为显示游标和隐示游标。下面有两个实例然码实践这两个例子
cursor c_name(var_name var_type)
is|as
select ...
from ...<--游标的语法->
where...
游标的属性：
%isopen<--是否打开->
%found
%notfound
%rowcount
用法：
open
fetch
close
create or replace function f_get_ename(p_deptno number)
return number is
s_sum number ;
tem number ;
--显示游标
cursor c1(p_salary hr.employees.salary%type)
is
select emp.salary
from hr.employees emp
where emp.employee_id > p_deptno and emp.employee_id < 205;
begin
s_sum := 0 ;
--打开游标
open c1(202);
loop
--取数据
fetch c1 into tem;
exit when c1%notfound;
s_sum := s_sum + tem ;
end loop;
dbms_output.put_line(c1%rowcount) ;
close c1;
return s_sum ;
end;
--隐式游标
create or replace function f_get_ename(p_deptno number) return number is
s_sum number;
begin
s_sum := 0;
--隐式游标
for c1 in (select emp.salary
from hr.employees emp
where emp.employee_id > p_deptno
and emp.employee_id < 205) loop
s_sum := s_sum + c1.salary;
end loop;
return s_sum;
end;