ORACLE 游标的4种应用方法

8996q9k489

--1.普通cursor
set serveroutput on;
declare
num1 number;
num2 number;
cursor SEQ is select SEQ,JCXM from test;
begin
OPEN SEQ;   
loop
fetch SEQ into num1, num2;
dbms_output.put_line(num1||','||num2);
exit when SEQ%NOTFOUND;
end loop;
CLOSE SEQ;
Exception
When others then
Rollback;
end;
--2.使用FOR循环的游标1;
declare
num1 number;
num2 number;
cursor SEQ is select SEQ,JCXM from test;
begin
for seq_r in SEQ loop
dbms_output.put_line(seq_r.seq||','||seq_r.jcxm);
end loop;
Exception
When others then
Rollback;
end;
--3.使用FOR循环的游标2;
declare
num1 number;
num2 number;
cursor SEQ is select SEQ,JCXM from test;
begin
for seq_r in (select SEQ,JCXM from test ) loop
dbms_output.put_line(seq_r.seq||','||seq_r.jcxm);
END loop;
Exception
When others then
Rollback;
end;
--4.带参数的游标
declare
num1 number;
num2 number;
cursor SEQ(seqNum number ) is select SEQ,JCXM from test where seq = seqNum;
begin
for seq_r in SEQ(11) loop
dbms_output.put_line(seq_r.seq||','||seq_r.jcxm);
END loop;
Exception
When others then
Rollback;
end;






　　
游标for循环的优点是：用户不需要打开游标，去数据，测试数据的存在，关闭游标或者定义存放数据的变量。
　　缺点就不知道了，会不会影响速度呢？