Question

在MS SQL和Sybase中，我们将查询的计数分配给变量，如下所示。

declare @rate_count int
select count(1) "Count"  =   @rate_count
from 
(select DISTINCT RATE_CODE from APPROVED_RATE RATE
where RATE.RATE_CHNG_IND = 'Y')

然而，在甲骨文中，我甚至无法宣布？任何帮助因为取决于值返回，While循环开始像

while (@rate_count > 1)
Begin
--

End

Answer 1

当然你可以声明..

Declare 

rate_count number; 

begin 

select count(1) into rate_count
from 
(select DISTINCT RATE_CODE from APPROVED_RATE RATE
where RATE.RATE_CHNG_IND = 'Y');


dmbs_output.put_line(rate_count);
end;

Answer 2

您可以在Oracle中使用以下内容：

SQL> set serveroutput on;
SQL> declare 
 rate_count int;
begin 
 select count(1) "Count" into rate_count from (select DISTINCT RATE_CODE from APPROVED_RATE RATE where RATE.RATE_CHNG_IND = 'Y');
 dbms_output.put_line('Your Rate Count is : '||rate_count);
end;

Answer 3

Oracle不允许我们在块的declare部分执行SQL语句。所以你需要做的是：

declare 
    rate_count pls_integer;
begin
    select count(DISTINCT RATE_CODE) 
    into rate_count 
    from APPROVED_RATE RATE
    where RATE.RATE_CHNG_IND = 'Y';

    while rate_count > 1 loop
        ....

小心那个WHILE。除非你减少rate_count或者有其他EXIT条件，否则代码将永远循环。也许你的意思是：

for idx in 1 .. rate_count loop

使用declare在Oracle中声明局部变量

3 个答案: