使用集合時oracle pl / sql中的no_data_found異常

Question

DECLARE
   TYPE EmpList IS TABLE OF varchar2(50) INDEX BY BINARY_INTEGER;

   temp    SYS_REFCURSOR;
   v_temp  varchar2(50);
   v_emp   EmpList;
BEGIN
   v_emp (1) := 'gaurav';
   v_emp (2) := 'manu';

   open temp for select v_emp(level) from dual connect by level<=2;
   loop
    fetch temp into v_temp;
     exit when temp%notfound;
       DBMS_OUTPUT.put_line (v_temp);
    end loop;
   close temp;

--the below part works, then why not the above part dint works
 for i in v_emp.first..v_emp.last
  loop
      dbms_output.put_line(v_emp(i));
  end loop;

EXCEPTION
   WHEN OTHERS
   THEN
      DBMS_OUTPUT.put_line (SQLERRM);
END;

誰能告訴我為什么這個集合在這里工作？，它給了我no_data_found異常。

Answer 1

失敗的原因是

v_emp(level) 

在運行時被評估（作為它的一個變量），所以實際上會在所有行上評估為v_emp(0);

如果您將陣列更改為，則可以看到此內容

v_emp (0) := 'gaurav';
v_emp (1) := 'manu';

正確的方法（如果你不知道）是：

create TYPE EmpList IS TABLE OF varchar2(50);
/

接着 ：

v_emp := EmpList('gaurav', 'manu');
open temp for select column_value from table(v_emp);

Answer 2

嘗試這個：

DECLARE
   TYPE EmpList IS TABLE OF varchar2(50) INDEX BY BINARY_INTEGER;

   temp    SYS_REFCURSOR;
   v_temp  varchar2(50);
   v_emp   EmpList;
BEGIN
   v_emp (0) := 'gaurav';
   v_emp (1) := 'manu';

   open temp for select v_emp(level) from dual connect by level<=2;
   loop
    fetch temp into v_temp;
        exit when temp%notfound;
       DBMS_OUTPUT.put_line ('v_temp' || v_temp);
    end loop;
   close temp;

--the below part works, then why not the above part dint works
 for i in v_emp.first..v_emp.last
  loop
      dbms_output.put_line(v_emp(i));
  end loop;

EXCEPTION
   WHEN OTHERS
   THEN
      DBMS_OUTPUT.put_line (SQLERRM);
END;