参考光标类型 oracle

Posted 2023-03-28

【中文标题】参考光标类型 oracle

【英文标题】：Ref Cursor Type oracle

【发布时间】：2012-12-11 07:42:46

【问题描述】：

我想检查光标是否只有一行。 并返回这个，

--请看我的问题在程序里面吗？

    CREATE OR REPLACE PROCEDURE GetInterestRate( p_id    IN NUMBER DEFAULT NULL,
       RC1             IN OUT SYS_REFCURSOR
    )
    ....


    begin
      open rc1 for select * from interestRatesTable i  join parametersInterest p on 
i.interestName = p.Name
 where i.idinterest  = p_id
and p.Active ='A';
     -- I would like to check if cursor have only one row.
    --- if it has zero row, no result I got to raise an error
    --- if it has more than one row, I got to raise to many interest rates!
    -- how can I do this?
    end;

【问题讨论】：

和java有什么关系？

我认为java开发人员应该熟悉这个案例。我只是为了礼貌而删除......

【参考方案1】：

Oracle 会为您提出错误，只需在一行中选择一个值 我想你也应该在异常块中捕获异常。

 CREATE OR REPLACE PROCEDURE GetInterestRate( p_id    IN NUMBER DEFAULT NULL,
   RC1             IN OUT SYS_REFCURSOR
)
....

 begin
   select 1
   into   a_value
   from   interestRatesTable i  
   join parametersInterest p ...    

   open rc1 for ......
 EXCEPTION 
   WHEN NO_DATA_FOUND THEN
     .....
   WHEN TOO_MANY_ROWS THEN
     .....
   WHEN OTHERS THEN
     .....
 end;

【参考方案2】：

我认为您必须先运行查询才能打开光标。

 CREATE OR REPLACE PROCEDURE ...
 begin
   select count(*)
   into   row_found
   from   interestRatesTable i  join parametersInterest p ...
   and    rownum = 1;

   if row_found = 0 then raise ...
   end if
   open ...

 end;