SQL & PL/SQL

Hi ,

the follwing SQL generates Zero's prefixed to the rownum. While inserting the data into table all the zero's go away
why ?

How can i insert data with Zero's ?


<SQL>

select
(Case length(rownum)
when 1 then '0000'||rownum
when 2 then '000'||rownum
when 3 then '00'||rownum
when 4 then '0'||rownum
else
to_char(rownum)
END )



from

(

SELECT o.class_code d
FROM sun_oracle_schedule_backup@ougbs_ougbs.world o

Union

SELECT to_number(m.schedule_id,'99999') d
FROM sun_MYSQL_schedule_backup@ougbs_ougbs.world M

Union

SELECT o.class_code d
FROM sun_internal_schedule_backup@ougbs_ougbs.world o

)

<SQL>


Out put of the above query
-----------------------------------------------


00001
00002
00003
00004
00005
00006
00007


When used with INSERT statement the table has the values as
--------------------------------------------------------------------------------------

1
2
3
4
5
6
7


Where did the Zero's GO?????



the table column data type is Number......




Thanks

--- Raj