Oracle中的for和while循环
有两种方式可以实现条件循环
一、for 变量 in 开始数值...结束数值 loop end loop;
二、while 条件 loop end loop;
loop的使用方式:
exit when 语句可以出现在循环代码中的任何位置;
for循环:
begin
for x in reverse 1..10 loop -- reverse大到小
DBMS_OUTPUT.PUT_LINE('内:x='||x);
end loop;
DBMS_OUTPUT.PUT_LINE('endget');
end;
如以下两个例:
1)
Create Or Replace Procedure Count_Number Is
i Number(10);
t Number(10);
Begin
i := 1;
t := 0;
Loop
i:=i+1;
---exit when i=100;
exit when i>100;
t:=t+i;
Dbms_Output.Put_Line('it''s :' || t);
end loop;
---Dbms_Output.Put_Line('it''s :' || t);
End Count_Number;
2)
Create Or Replace Procedure Count_Number Is
i Number(10);
t Number(10);
Begin
i := 1;
t := 0;
Loop
i:=i+1;
if i=100 then
exit;
end if ;
t:=t+i;
Dbms_Output.Put_Line('it''s :' || t);
end loop;
---Dbms_Output.Put_Line('it''s :' || t);
End Count_Number;
注:以上的结论都是一样的 !
以下是一个非常简单的过程,用来熟悉循环的!
1)使用while ....loop ....end loop ;
Create Or Replace Procedure Count_Number Is
i Number(10);
t Number(10);
Begin
i := 1;
t := 0;
while i<=100 loop
t:=t+i;
i:=i+1;
Dbms_Output.Put_Line('it''s :' || t);
end loop;
---Dbms_Output.Put_Line('it''s :' || t);
End Count_Number;
2)用for实现:for i in 1..l00 loop ....end loop ;
Create Or Replace Procedure Count_Number Is
i Number(10);
t Number(10);
Begin
--- i := 1;
t := 0;
for i in 1..100 loop
t:=t+i;
Dbms_Output.Put_Line('it''s :' || t);
end loop;
---Dbms_Output.Put_Line('it''s :' || t);
End Count_Number;
for循环:
[PL/SQL] 用For Loop 替代Cursor
http:
http:
CURSOR FOR Loop
FOR employee_rec in c1 ---employee_rec直接用,不用提前定义
LOOP
total_val := total_val + employee_rec.monthly_income;
END LOOP;
当使用CURSOR FOR Loop时,不用我手工open cursor close cursor
应用:
begin
FOR emm IN ( SELECT ro_site, ns_site, product_line, wh_type
FROM eis_hq_invhl_mail_data
WHERE report_type = 'Detailed' )
LOOP
DBMS_OUTPUT.put_line( emm.product_line );
eis_hq_invhl_pkg.make_mail_detailed_data
( p_ro_site => emm.ro_site,
p_ns_site => emm.ns_site,
p_product_line => emm.product_line,
p_wh_type => emm.wh_type,
p_current_day => to_date('2005-11-07','yyyy-MM-dd') );
END LOOP;
end;
存储过程DIY2----游标与循环
http:
while循环:
WHILE( i <= CEIL( LENGTH( p_clob_data ) / 4000 ))
LOOP
v_clob_data := TRIM( SUBSTR( p_clob_data,
i * 4000,
4000 ));
DBMS_OUTPUT.put_line( SUBSTR( v_clob_data,
0,
255 ));
i := i + 1;