oracle|控制|循环|语法|语句
1.简单循环
loop
sequence of statements;
end loop;
例:
declare
a number:=100;
begin
loop
a:=a+25;
exit when a=250;
end loop;
dbms_output.put_line(to_char(a));--注意这里用to_char()
end;
2.For循环
For counter in [Reverse]lowerbound…upperbound
loop
sequence of statements;
end loop;
counter是计数器变量,此处不用声明,此变量在循环体中只能读取,不能赋值。如i++是错误的
lowbound是下界
upperbound是上界,默认情况下,从下界到上界进行迭代,如果使用关键字Reverse,则从上界到下界进行迭代
例:
begin
for i in 1..2--如果反向,使用Reverse关键字即可
loop
update order_master set ostatus='p' where odate<sysdate;
end loop;
end;
3.While循环
while <condition>
loop
sequence of statements;
end loop;
例:
declare
i number:=0;
j number:=0;
begin
while i<=100 loop
j:=j+i;
i:=i+2;
end loop;
end;
时间: 2024-08-04 10:40:46