对比: sql函数转成oracle函数

SQL:
Create Function Union_TIMECARDDATA(@ID nvarchar(40),@Date Varchar(10))
Returns Varchar(1000)
As
Begin
Declare @S Varchar(1000)
Set @S=''
Select @S=@S+TimeCardTime+',' From ATDTIMECARDDATA Where PERSONID=@ID And TimeCardDate=@Date
 Order By PERSONID,TimeCardDate,TimeCardTime
Return(Left(@S,Len(@S)-1))
End
GO

1. 不要@符号
2. 句末加;号
3. 不要declare
4. =号改:=
5. @S=@S+TimeCardTime 要用游标循环 for 变量 in (...) loop  ... end loop

ORACLE:
create or replace function Union_TIMECARDDATA(v_ID nvarchar2,v_Date Varchar2)
return varchar2
as
 v_s varchar2(1000);
begin
  v_s := '';
  for rec in(Select TimeCardTime From ATDTIMECARDDATA
             Where PERSONID=v_ID And TimeCardDate=v_Date
             Order By PERSONID,TimeCardDate,TimeCardTime
            )
  loop
    v_s := v_s||rec.TimeCardTime||','; 
  end loop;
  v_s := substr(v_s,1,length(v_s)-1);
  return v_s;
end;
/