Oracle PL/SQL - 使用“SELECT INTO”时出现 ORA-01403“未找到数据”

Question

我有一个 pl sql 代码，它按顺序执行三个查询以确定匹配级别并执行一些逻辑
问题是 - 当第一个查询没有结果（完全有效的场景）时，我得到 ORA-01403 找不到数据。
我知道我需要在 NO_DATA_FOUND 时加入 [Exception 子句]-但是如何添加它并继续下一个查询？

PL/SQL Code
     SELECT A into PARAM A FROM SAMPLE WHERE SOME CONDITION;
     --  GOT ORA-01403  No data found HERE 

     MATCH_LEVEL =1;
     if A is null then 
          do some logic;
     end if


     SELECT A INTO PARAM_B FROM SAMPLE WHERE SOME OTHER CONDITION
     MATCH_LEVEL =2
     if A is null then 
          do some logic 2;
     end if



     SELECT A INTO PARAM_B FROM SAMPLE WHERE SOME OTHER CONDITION
     MATCH_LEVEL =3
     if A is null then 
          do some logic 3;
     end if

END    PL/SQL Code

Answer 1

Declare
--your declarations 
begin
SELECT A into PARAM A FROM SAMPLE WHERE SOME CONDITION;
 --  GOT ORA-01403  No data found HERE 

 Begin

   MATCH_LEVEL =1;
   if A is null then 
        do some logic;
   end if;
 EXCEPTION 
 WHEN NO_DATA_FOUND THEN 
  dbms_output.put_line ('Error...'); 
 END; 
 --- and son on for other blocks

end;

Answer 2

只要你的周围SELECT INTO用begin-end;

begin 

    -- your faulty statement here
Exception
When NO_DATA_FOUND Then
    -- Do what you want or nothing 
WHEN TOO_MANY_ROWS THEN
    -- what if you get more then one row? and need specific handler for this 
When OTHERS Then
    -- do something here or nothing (optional - may happen if you have more than your SELECT INTO between 'begin' and 'Exception')

end;

这就像try块PL/Sql

使用此技术，您可以记录语句失败的原因。