Oracle ORA-06575:包或函数F处于无效状态

当我执行函数时，请给出以下错误：

CREATE or replace FUNCTION  f
return integer
AS;
BEGIN 
  return (select count(*) from exemplo); 
END ;

select f() from dual;

---

运行

alter会话集nls_language='English'以获取英文错误消息

函数必须如下所示：

ORA-06575: Package or function F is in an invalid state

编译函数时，客户端会说：

CREATE or replace FUNCTION  f return integer AS
   ret INTEGER;
BEGIN 
   select count(*) INTO ret from exemplo; 
   return ret;
END;

LINE/COL ERROR
-------- -----------------------------------------------------------------
5/11     PLS-00103: Encountered the symbol "SELECT" when expecting one of the following:
         ( - + case mod new not null <an identifier>
         <a double-quoted delimited-identifier> <a bind variable>
         continue avg count current exists max min prior sql stddev
         sum variance execute forall merge time timestamp interval
         date <a string literal with character set specification>
         <a number> <a single-quoted SQL string> pipe
         <an alternatively-quoted string literal with character set specification>
         <an alternat
5/39     PLS-00103: Encountered the symbol ")" when expecting one of the following:
         . , @ ; for <an identifier>
         <a double-quoted delimited-identifier> group having intersect
         minus order partition start subpartition union where connect
         sample

或

如果您使用的是SQL*Plus或SQL Developer（可能还有其他客户端，但它们可能有自己的等效客户端），那么您可以执行
显示错误
以查看错误：

Function F compiled

Errors: check compiler log

不能直接返回查询结果。您需要选择一个局部变量，然后返回；比如：

CREATE or replace FUNCTION  f return integer AS
   ret INTEGER;
BEGIN 
   select count(*) INTO ret from exemplo; 
   return ret;
END;

LINE/COL ERROR
-------- -----------------------------------------------------------------
5/11     PLS-00103: Encountered the symbol "SELECT" when expecting one of the following:
         ( - + case mod new not null <an identifier>
         <a double-quoted delimited-identifier> <a bind variable>
         continue avg count current exists max min prior sql stddev
         sum variance execute forall merge time timestamp interval
         date <a string literal with character set specification>
         <a number> <a single-quoted SQL string> pipe
         <an alternatively-quoted string literal with character set specification>
         <an alternat
5/39     PLS-00103: Encountered the symbol ")" when expecting one of the following:
         . , @ ; for <an identifier>
         <a double-quoted delimited-identifier> group having intersect
         minus order partition start subpartition union where connect
         sample

为什么在
后面有一个分号作为
？编译函数后，它会告诉您有错误；使用
show errors
或查询
user\u errors
视图查看实际错误。无论是否存在错误，它们都不起作用
CREATE or replace FUNCTION  f
return integer
AS
  l_count pls_integer;
BEGIN 
  select count(*) into l_count from exemplo;
  return l_count; 
END ;
/