尝试打印输出时出现 pls-00306 错误答案

【问题标题】：pls-00306 error when trying to print output尝试打印输出时出现 pls-00306 错误
【发布时间】：2021-04-27 12:58:25
【问题描述】：

此代码块在调用“put_line”时返回错误 pls-00306 错误数量或类型的参数：

SET SERVEROUTPUT ON
DECLARE  
   ch varchar2(16);
   cursor ebs_user_cur 
   is
   select xmlagg(xmlelement("r", ch)).extract('//text()').getstringval() 
from
(
  select distinct first_value(ch) over (partition by lower(ch))  
  from (
    select substr('abcd#efghijklmn#pqrstuvwxyzABC$DEFGHIJK$LMNPQR!STUVWXYZ1!23456789',
        level, 1)  ch
    from dual 
    connect by level <= 59
    order by dbms_random.value
  )
  where rownum <= dbms_random.value(18,18)
);
l_passwd   ebs_user_cur%ROWTYPE;
BEGIN
open ebs_user_cur;
loop
fetch ebs_user_cur into l_passwd;
DBMS_OUTPUT.PUT_LINE(l_passwd);
EXIT WHEN l_passwd%NOTFOUND;
END LOOP;
close ebs_user_cur;
END;

哪里出错了？

谢谢

【问题讨论】：

标签： oracle plsql

【解决方案1】：

您应该在光标中指定列别名
您应该在l_passwd.{field_name} 中指定准确的字段名称：

SET SERVEROUTPUT ON
DECLARE  
   ch varchar2(16);
   cursor ebs_user_cur 
   is
   select xmlagg(xmlelement("r", ch)).extract('//text()').getstringval() 
    as res -- <<< see here
    from
    (
      select distinct first_value(ch) over (partition by lower(ch))  
      from (
        select substr('abcd#efghijklmn#pqrstuvwxyzABC$DEFGHIJK$LMNPQR!STUVWXYZ1!23456789',
            level, 1)  ch
        from dual 
        connect by level <= 59
        order by dbms_random.value
      )
      where rownum <= dbms_random.value(18,18)
    );
    l_passwd   ebs_user_cur%ROWTYPE;
BEGIN
  open ebs_user_cur;
  loop
    fetch ebs_user_cur into l_passwd;
    DBMS_OUTPUT.PUT_LINE(l_passwd.res); -- <<< .res here
    EXIT WHEN l_passwd%NOTFOUND;
  END LOOP;
  close ebs_user_cur;
END;

【讨论】：