Question

我想在查询未获取任何记录时引发自定义错误。但是下面的代码没有抛出我想要的错误。它引发系统生成错误。请你帮助我好吗？我在犯什么错误？

DECLARE
v_em_id NUMBER := &var_id;
v_name varchar2(20);
BEGIN
SELECT first_name INTO v_name FROM employees WHERE employee_id =v_em_id;
IF SQL%NOTFOUND THEN
RAISE_APPLICATION_ERROR(-20002,'Employee not exist');
END IF;
DBMS_OUTPUT.PUT_LINE('Hi! '|| v_name);
END;

我应该抛出错误代码：-20002 和错误消息：员工不存在。

Answer 1

您可以尝试以下代码...

<a href="series-1.html" class="s1">Series 1
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如果DECLARE v_em_id NUMBER := &var_id; v_name varchar2(20); BEGIN SELECT first_name INTO v_name FROM employees WHERE employee_id = v_em_id; DBMS_OUTPUT.PUT_LINE('Hi! ' || v_name); EXCEPTION WHEN NO_DATA_FOUND THEN IF SQL%NOTFOUND THEN RAISE_APPLICATION_ERROR(-20002, 'Employee not exist'); END IF; END;语句不返回任何行，它将引发select异常。因此，系统在no_data_found行之前失败了。

Answer 2

SQL%NOTFOUND在这里没有用。如果未找到任何内容，则会引发NO_DATA_FOUND异常，因此您必须处理该异常。这是一个基于Scott模式的示例：

SQL> declare
  2    v_em_id number := &empno;
  3    v_name  varchar2(20);
  4  begin
  5    select ename
  6      into v_name
  7      from emp
  8      where empno = v_em_id;
  9
 10    dbms_output.put_line('Hi, ' || v_name);
 11  exception
 12    when no_data_found then
 13      raise_application_error(-20002, 'Employee does not exist');
 14  end;
 15  /
Enter value for empno: 7934
Hi, MILLER

PL/SQL procedure successfully completed.

SQL> /
Enter value for empno: 111
declare
*
ERROR at line 1:
ORA-20002: Employee does not exist
ORA-06512: at line 13


SQL>

为什么在此代码中RAISE_APPLICATION_ERROR（）函数不起作用？

2 个答案: