WMSYS.WM_CONCAT 突破4000字符的方法

1.

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 VARCHAR2, FLAGS IN NUMBER) RETURN NUMBER, MEMBER FUNCTION ODCIAGGREGATEMERGE(SELF IN OUT zh_concat_im, SCTX2 IN zh_concat_im) RETURN NUMBER );

2.

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 VARCHAR2,

  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;

3.

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