WMSYS.WM_CONCAT 过长问题的解决

在项目中，出现了使用WMSYS.WM_CONCAT合并列内容，导致内容过长出现异常。

 select bill_id, WMSYS.WM_CONCAT(message) as message  from tblbill_msg group by bill_id 

 

网上查了资料，使用自定义类型方式进行处理。

 

----------创建自定义类型

CREATE OR REPLACE TYPE zh_concat_im
AUTHID CURRENT_USER AS OBJECT
(
  CURR_STR clob,
  STATIC FUNCTION ODCIAGGREGATEINITIALIZE(SCTX IN OUT zh_concat_im) RETURN NUMBER,
  MEMBER FUNCTION ODCIAGGREGATEITERATE(SELF IN OUT zh_concat_im,
  P1 IN VARCHAR2) RETURN NUMBER,
  MEMBER FUNCTION ODCIAGGREGATETERMINATE(SELF IN zh_concat_im,
  RETURNVALUE OUT clob,
  FLAGS IN NUMBER)
  RETURN NUMBER,
  MEMBER FUNCTION ODCIAGGREGATEMERGE(SELF IN OUT zh_concat_im,
  SCTX2 IN zh_concat_im) RETURN NUMBER
);

-----------------
CREATE OR REPLACE TYPE BODY zh_concat_im
IS
  STATIC FUNCTION ODCIAGGREGATEINITIALIZE(SCTX IN OUT zh_concat_im)
  RETURN NUMBER
  IS
  BEGIN
  SCTX := zh_concat_im(NULL) ;
  RETURN ODCICONST.SUCCESS;
  END;
  MEMBER FUNCTION ODCIAGGREGATEITERATE(SELF IN OUT zh_concat_im,

  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 zh_concat_im,
  RETURNVALUE OUT clob,
  FLAGS IN NUMBER)
  RETURN NUMBER
  IS
  BEGIN
  RETURNVALUE := CURR_STR ;
  RETURN ODCICONST.SUCCESS;
  END;
  MEMBER FUNCTION ODCIAGGREGATEMERGE(SELF IN OUT zh_concat_im,
  SCTX2 IN zh_concat_im)
  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;

 ------------创建函数

create or replace FUNCTION zh_concat(P1 VARCHAR2)
RETURN clob AGGREGATE USING zh_concat_im ;

 完整创建后，进行调用处理：

 select bill_id, (case when  count(message) <> 1 then '内容过长发送请查看<短信记录>'
 else to_char(zh_concat(message)) end) as message
 from tblbill_msg group by bill_id