ORA-00904: "WM_CONCAT": invalid identifier 解决方案

背景：由于技术架构的调整，数据库需要进行迁移，将表和存储过程从Oracle数据库迁移到另外一个Oracle数据库，在存储过程迁移过程中，遇到个问题，使用WM_CONCAT的存储过程编译不会通过，并且报 ORA-00904: "WM_CONCAT": invalid identifier 错误。

产生原因：在查一些资料后，发现11gr2之后的版本中WM_CONCAT函数已经弃用，而应用在程序中确使用了该函数，导致程序出现错误。

解决方案：

1、如果你是11gR2之后的版本，建议使用LISTAGG代替WM_CONCAT

with mock_data as(
select 'Mike' NAME , 1 aa from dual
union all
select 'Amber' NAME,2 from dual
union all
select 'James' NAME,3 from dual
union all
select 'Albert' NAME,4 from dual
)
SELECT 
       LISTAGG(NAME, ', ') WITHIN GROUP (ORDER BY name)  name_list
FROM mock_data
;

NAME_LIST                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
--------------------------
Mike, Amber, James, Albert

2、自己创建WM_CONCAT函数

CREATE OR REPLACE TYPE wm_concat_impl
   AUTHID CURRENT_USER
AS OBJECT (
   curr_str   VARCHAR2 (32767),
   STATIC FUNCTION odciaggregateinitialize (sctx IN OUT wm_concat_impl)
      RETURN NUMBER,
   MEMBER FUNCTION odciaggregateiterate (
      SELF   IN OUT   wm_concat_impl,
      p1     IN       VARCHAR2
   )
      RETURN NUMBER,
   MEMBER FUNCTION odciaggregateterminate (
      SELF          IN       wm_concat_impl,
      returnvalue   OUT      VARCHAR2,
      flags         IN       NUMBER
   )
      RETURN NUMBER,
   MEMBER FUNCTION odciaggregatemerge (
      SELF    IN OUT   wm_concat_impl,
      sctx2   IN       wm_concat_impl
   )
      RETURN NUMBER
);
/

CREATE OR REPLACE TYPE BODY wm_concat_impl
IS
   STATIC FUNCTION odciaggregateinitialize (sctx IN OUT wm_concat_impl)
      RETURN NUMBER
   IS
   BEGIN
      sctx := wm_concat_impl (NULL);
      RETURN odciconst.success;
   END;
   MEMBER FUNCTION odciaggregateiterate (
      SELF   IN OUT   wm_concat_impl,
      p1     IN       VARCHAR2
   )
      RETURN NUMBER
   IS
   BEGIN
      IF (curr_str IS NOT NULL)
      THEN
         curr_str := curr_str || ',' || p1;
      ELSE
         curr_str := p1;
      END IF;

      RETURN odciconst.success;
   END;
   MEMBER FUNCTION odciaggregateterminate (
      SELF          IN       wm_concat_impl,
      returnvalue   OUT      VARCHAR2,
      flags         IN       NUMBER
   )
      RETURN NUMBER
   IS
   BEGIN
      returnvalue := curr_str;
      RETURN odciconst.success;
   END;
   MEMBER FUNCTION odciaggregatemerge (
      SELF    IN OUT   wm_concat_impl,
      sctx2   IN       wm_concat_impl
   )
      RETURN NUMBER
   IS
   BEGIN
      IF (sctx2.curr_str IS NOT NULL)
      THEN
         SELF.curr_str := SELF.curr_str || ',' || sctx2.curr_str;
      END IF;

      RETURN odciconst.success;
   END;
END;
/

CREATE OR REPLACE FUNCTION wm_concat (p1 VARCHAR2)
   RETURN VARCHAR2
   AGGREGATE USING wm_concat_impl;
/

复制粘贴执行即可。

若之前使用WM_CONCAT较多，建议使用方法2创建函数，但之后需要进行聚合的时候建议使用LISTAGG。