测试代码：

DECLARE  TYPE list_of_names_t IS TABLE OF VARCHAR2(100) INDEX BY PLS_INTEGER;  happyfamily list_of_names_t;  l_row       PLS_INTEGER;BEGIN  --build table data which index is not consecutive.  happyfamily(2020202020) := 'Eli';  happyfamily(-15070) := 'Steven';  happyfamily(-90900) := 'Chris';  happyfamily(-90899) := 'Chris90899';  happyfamily(88) := 'Veva';  <
    
     >  BEGIN    dbms_output.put_line('=======err1========');    --i is starting from 1 and increase one by one.    FOR i IN 1 .. happyfamily.COUNT    LOOP      dbms_output.put_line(i);      dbms_output.put_line(happyfamily(i));    END LOOP;  EXCEPTION    WHEN OTHERS THEN      dbms_output.put_line('err1=>' || SQLERRM);  END;  <
     
      >  BEGIN    dbms_output.put_line('=======err2========');    --i is starting from -90900 and increase one by one.    FOR i IN happyfamily.FIRST .. happyfamily.LAST    LOOP      dbms_output.put_line(i);      dbms_output.put_line(happyfamily(i));    END LOOP;  EXCEPTION    WHEN OTHERS THEN      dbms_output.put_line('err2=>' || SQLERRM);  END;  <
      
       >  BEGIN    dbms_output.put_line('=======pass========');    --i is starting from -90900 and increase discrete    l_row := happyfamily.FIRST;    WHILE (l_row IS NOT NULL)    LOOP      dbms_output.put_line(l_row);      dbms_output.put_line(happyfamily(l_row));      l_row := happyfamily.NEXT(l_row);    END LOOP;  EXCEPTION    WHEN OTHERS THEN      dbms_output.put_line('err3=>' || SQLERRM);  END;END;
      
     
    

输出：

=======err1========1err1=>ORA-01403: no data found=======err2========-90900Chris-90899Chris90899-90898err2=>ORA-01403: no data found=======pass========-90900Chris-90899Chris90899-15070Steven88Veva2020202020Eli