Oracle循环语句及例子（几种循环语句的语法）

几种循环语句

1、loop语句
loop
sentence;
exit when 条件
end loop;
2、while语句
while 条件 loop
sentence;
end loop;
3、for语句（变量名为自带计数器）
for 变量名 in [reverse] lower_limit..upper_limit loop
sentence;
end loop;

举例：

set serveroutput on;
--查询employees所有员工的工资总和
declare a1 number;
        a2 number(8,2);
begin
--loop循环语句实现
select count(*) into a1 from employees;
a2:=0;
loop 
select  nvl(salary,0)+a2 into a2 from (select salary,rownum num from employees ) where num=a1;
a1:=a1-1;
exit when  a1<=0;
end loop;
dbms_output.put_line('loop循环得到所有员工的薪资总和是：'||a2);
--while循环语句实现
select count(*) into a1 from employees;
a2:=0;
while a1>0 loop
select  nvl(salary,0)+a2 into a2 from (select salary,rownum num from employees ) where num=a1;
a1:=a1-1;
exit when  a1<=0;
end loop;
dbms_output.put_line('while循环得到所有员工的薪资总和是：'||a2);
--loop循环语句实现
select count(*) into a1 from employees;
a2:=0;
for i in 1..a1 loop
select  nvl(salary,0)+a2 into a2 from (select salary,rownum num from employees ) where num=i;
end loop;
dbms_output.put_line('for循环得到所有员工的薪资总和是：'||a2);
end;

执行结果：

匿名块已完成
loop循环得到所有员工的薪资总和是：691416
while循环得到所有员工的薪资总和是：691416
for循环得到所有员工的薪资总和是：691416

博文仅供参考，欢迎大家来访。如有错误之处，希望批评指正。