Can i create a function which can take infinite parameter.

Question

Can i make a function which get infinite parameter.
like avg.

Answer 1

Kamran Riaz wrote:
Can i make a function which get infinite parameter.
like avg.I think you'll have trouble finding anything to take infinite parameters cos that would be bigger than the universe itself.
User defined aggregate functions example...
http://asktom.oracle.com/pls/asktom/f?p=100:11:335287534824285::::P11_QUESTION_ID:229614022562
[email protected]> create or replace type StringAggType as object
  2  (
  3     theString varchar2(4000),
  4 
  5     static function
  6          ODCIAggregateInitialize(sctx IN OUT StringAggType )
  7          return number,
  8 
  9     member function
10          ODCIAggregateIterate(self IN OUT StringAggType ,
11                               value IN varchar2 )
12          return number,
13 
14     member function
15          ODCIAggregateTerminate(self IN StringAggType,
16                                 returnValue OUT  varchar2,
17                                 flags IN number)
18          return number,
19 
20     member function
21          ODCIAggregateMerge(self IN OUT StringAggType,
22                             ctx2 IN StringAggType)
23          return number
24  );
25  /
Type created.
[email protected]>
[email protected]> create or replace type body StringAggType
  2  is
  3 
  4  static function ODCIAggregateInitialize(sctx IN OUT StringAggType)
  5  return number
  6  is
  7  begin
  8      sctx := StringAggType( null );
  9      return ODCIConst.Success;
10  end;
11 
12  member function ODCIAggregateIterate(self IN OUT StringAggType,
13                                       value IN varchar2 )
14  return number
15  is
16  begin
17      self.theString := self.theString || ',' || value;
18      return ODCIConst.Success;
19  end;
20 
21  member function ODCIAggregateTerminate(self IN StringAggType,
22                                         returnValue OUT varchar2,
23                                         flags IN number)
24  return number
25  is
26  begin
27      returnValue := rtrim( ltrim( self.theString, ',' ), ',' );
28      return ODCIConst.Success;
29  end;
30 
31  member function ODCIAggregateMerge(self IN OUT StringAggType,
32                                     ctx2 IN StringAggType)
33  return number
34  is
35  begin
36      self.theString := self.theString || ',' || ctx2.theString;
37      return ODCIConst.Success;
38  end;
39 
40 
41  end;
42  /
Type body created.
[email protected]>
[email protected]> CREATE or replace
  2  FUNCTION stringAgg(input varchar2 )
  3  RETURN varchar2
  4  PARALLEL_ENABLE AGGREGATE USING StringAggType;
  5  /
Function created.
[email protected]>
[email protected]> column enames format a30
[email protected]> select deptno, stringAgg(ename) enames
  2    from emp
  3   group by deptno
  4  /
    DEPTNO ENAMES
        10 CLARK,KING,MILLER
        20 SMITH,FORD,ADAMS,SCOTT,JONES
        30 ALLEN,BLAKE,MARTIN,TURNER,JAME
           S,WARD
[email protected]>