Return specific number of rows depending on the data in a column in table

Question

Hi,
I have a table named orders which has column orderid and noofbookstoorder in addition to other columns.
I want to query the orders table and depending on the value of the 'noofbookstoorder' value return that number of rows.
Eg
Orderid noofbookstoorder
1 1
2 3
3 2
when I query the above data saying
select * from orders where orderid=2;
since it has noofbookstoorders value as 3 the query should return 3 rows and when I query
select * from orders where orderid=3;
it should return 2 rows and
select * from orders where orderid=1;
should return 1 row.
Is it possible to achieve this. If yes, then how do I write my query.
Thanks in advance.

Answer 1

with t as (
           select 1 Orderid,1 noofbookstoorder from dual union all
           select 2,3 from dual union all
           select 3,2 from dual
select  t.*
  from  t,
        table(cast(multiset(select 1 from dual connect by level <= noofbookstoorder) as sys.OdciNumberList))
  where Orderid = <order-id>
/For example:
SQL> with t as (
  2             select 1 Orderid,1 noofbookstoorder from dual union all
  3             select 2,3 from dual union all
  4             select 3,2 from dual
  5            )
  6  select  t.*
  7    from  t,
  8          table(cast(multiset(select 1 from dual connect by level <= noofbookstoorder) as sys.OdciNumberList))
  9    where Orderid = 2
10  /
   ORDERID NOOFBOOKSTOORDER
         2                3
         2                3
         2                3
SQL> with t as (
  2             select 1 Orderid,1 noofbookstoorder from dual union all
  3             select 2,3 from dual union all
  4             select 3,2 from dual
  5            )
  6  select  t.*
  7    from  t,
  8          table(cast(multiset(select 1 from dual connect by level <= noofbookstoorder) as sys.OdciNumberList))
  9    where Orderid = 3
10  /
   ORDERID NOOFBOOKSTOORDER
         3                2
         3                2
SQL> with t as (
  2             select 1 Orderid,1 noofbookstoorder from dual union all
  3             select 2,3 from dual union all
  4             select 3,2 from dual
  5            )
  6  select  t.*
  7    from  t,
  8          table(cast(multiset(select 1 from dual connect by level <= noofbookstoorder) as sys.Odc
iNumberList))
  9    where Orderid = 1
10  /
   ORDERID NOOFBOOKSTOORDER
         1                1
SQL>  -- And if you want to select multiple orders
SQL> with t as (
  2             select 1 Orderid,1 noofbookstoorder from dual union all
  3             select 2,3 from dual union all
  4             select 3,2 from dual
  5            )
  6  select  t.*
  7    from  t,
  8          table(cast(multiset(select 1 from dual connect by level <= noofbookstoorder) as sys.Odc
iNumberList))
  9    where Orderid in (2,3)
10  /
   ORDERID NOOFBOOKSTOORDER
         2                3
         2                3
         2                3
         3                2
         3                2
SQL> SY.
Edited by: Solomon Yakobson on Oct 26, 2009 7:36 AM