PL/SQL的loop循环

转载自网易博客http://blog.163.com/xuejelly1985@126/blog/static/362103402008823101415479/

1、for--loop循环

declare

s_no student.sno%type;

cursor c1 is

select sno from student where sno>'10001';

begin

for i in c1 loop

dbms_output.put_line(i.sno);

end loop;

end;

/

--游标的FOR循环，在FOR循环中，是隐含的自带游标的打开和关闭。

2、loop--end loop循环

declare

s_no student.sno%type;

cursor c1 is

select sno from student where sno>'10001';

begin

open c1;

loop

fetch c1 into s_no;

exit when c1%notfound;

dbms_output.put_line(s_no);

end loop;

close c1;

exception

when no_data_found then

dbms_output.put_line('no data1');

end;

/

--一般的LOOP循环，要显示的打开和关闭游标，而且要特别的注意循环条件的退出与输出的前后关系。

3、if判断

declare

cursor c1 is

select sno from student where sno>'10001';

begin

for i in c1 loop

if(i.sno<10004) then

dbms_output.put_line(i.sno);

end if;

end loop;

end;

/

--一种简单的条件判断。