Oracle 拼接字符串

Tom大神写的

CREATE OR REPLACE FUNCTION stragg(input varchar2) RETURN varchar2
  PARALLEL_ENABLE
  AGGREGATE USING string_agg_type;
--

CREATE OR REPLACE TYPE "STRING_AGG_TYPE" as object
(
  total varchar2(4000),
  static function ODCIAggregateInitialize(sctx IN OUT string_agg_type)
    return number,
  member function ODCIAggregateIterate(self  IN OUT string_agg_type,
                                       value IN varchar2) return number,
  member function ODCIAggregateTerminate(self        IN string_agg_type,
                                         returnValue OUT varchar2,
                                         flags       IN number)
    return number,
  member function ODCIAggregateMerge(self IN OUT string_agg_type,
                                     ctx2 IN string_agg_type) return number
)
--
create or replace type body string_agg_type is
  static function ODCIAggregateInitialize(sctx IN OUT string_agg_type)
    return number is
  begin
    sctx := string_agg_type(null);
    return ODCIConst.Success;
  end;
  member function ODCIAggregateIterate(self  IN OUT string_agg_type,
                                       value IN varchar2) return number is
  begin
    self.total := self.total || ',' || value;
    return ODCIConst.Success;
  end;
  member function ODCIAggregateTerminate(self        IN string_agg_type,
                                         returnValue OUT varchar2,
                                         flags       IN number) return number is
  begin
    returnValue := ltrim(self.total, ',');
    return ODCIConst.Success;
  end;
  member function ODCIAggregateMerge(self IN OUT string_agg_type,
                                     ctx2 IN string_agg_type) return number is
  begin
    self.total := self.total || ctx2.total;
    return ODCIConst.Success;
  end;
end;