Question - Comparing data from 2 databases

Question

I'm new to Oracle - I'm trying to compare data from 2 separate databases.
I'm trying to get data from both databases based on a common TRACKING_NUMBER. The issue is that in one database there are additional 0s in front of the Tracking_Number.
So I'm trying to find out what I can put in my query to remove those zero's in front of the tracking number. I have the query below - it's very long.
SELECT DISTINCT cm.TRACKING_NUMBER_TYPE AS HType,
TRUNC(cm.CREATED_DATE) as CodeMoveDate,
SUBSTR(cm.CODE_MOVE_DESC, 1, 50) AS Description,
cm.TRACKING_NUMBER AS TrackingNumber,
rq.Plant_Name as Location,
jr_eur.Assignee as Tracker,
TRUNC(MAX(jr_spec.Journal_Date)) as Date_Spec,
TRUNC(MAX(jr_app.Journal_Date)) as Date_Approved,
TRUNC(MAX(jr_ut.Journal_Date)) as Date_Unit,
TRUNC(MAX(jr_qa.Journal_Date)) as Date_Assurance,
TRUNC(MAX(jr_eur.Journal_Date)) as Date_Enduser,
TRUNC(MAX(jr_gv.Journal_Date)) as Date_Gatekeeper,
TRUNC(MAX(jr_prod.Journal_Date)) as Date_Move,
TRUNC(MAX(jr_eun.Journal_Date)) as Date_Notification,
TRUNC(MAX(jr_pver.Journal_Date)) as Date_Production,
TRUNC(MAX(jr_udoc.Journal_Date)) as Date_Documentation
FROM PROJMAN.PM_CODE_MOVES_V cm,
PROJMAN.PM_Requests_V rq,
PROJMAN.PM_Journals_V jr_spec,
PROJMAN.PM_Journals_V jr_app,
PROJMAN.PM_Journals_V jr_ut,
PROJMAN.PM_Journals_V jr_qa,
PROJMAN.PM_Journals_V jr_eur,
PROJMAN.PM_Journals_V jr_gv,
PROJMAN.PM_Journals_V jr_prod,
PROJMAN.PM_Journals_V jr_eun,
PROJMAN.PM_Journals_V jr_pver,
PROJMAN.PM_Journals_V jr_udoc
WHERE cm.TRACKING_NUMBER = LTRIM(rq.Request_ID(+))
AND cm.TRACKING_NUMBER = jr_spec.Request_ID(+)
AND cm.TRACKING_NUMBER = jr_app.Request_ID(+)
AND cm.TRACKING_NUMBER = jr_ut.Request_ID(+)
AND cm.TRACKING_NUMBER = jr_qa.Request_ID(+)
AND cm.TRACKING_NUMBER = jr_eur.Request_ID(+)
AND cm.TRACKING_NUMBER = jr_gv.Request_ID(+)
AND cm.TRACKING_NUMBER = jr_prod.Request_ID(+)
AND cm.TRACKING_NUMBER = jr_eun.Request_ID(+)
AND cm.TRACKING_NUMBER = jr_pver.Request_ID(+)
AND cm.TRACKING_NUMBER = jr_udoc.Request_ID(+)
AND jr_spec.Journal_Status(+) = 'Spec Doc'
AND jr_app.Journal_Status(+) = 'Approved'
AND jr_ut.Journal_Status(+) = 'Unit Test'
AND jr_qa.Journal_Status(+) = 'Quality Assurance'
AND jr_eur.Journal_Status(+) = 'End User Review'
AND jr_gv.Journal_Status(+) = 'Gatekeeper Verificat'
AND jr_prod.Journal_Status(+) = 'Move to Production'
AND jr_eun.Journal_Status(+) = 'End User Notificatio'
AND jr_pver.Journal_Status(+) = 'Production Verificat'
AND jr_udoc.Journal_Status(+) = 'User Documentation'
AND cm.TRACKING_NUMBER_TYPE = 'H'
and cm.CREATED_DATE >{d '2006-12-31'}
GROUP BY
cm.TRACKING_NUMBER_TYPE,
TRUNC(cm.CREATED_DATE),
cm.CODE_MOVE_DESC,
cm.TRACKING_NUMBER,
rq.Plant_Name,
jr_eur.Assignee
ORDER BY TRUNC(cm.CREATED_DATE)

Answer 1

I recommend using a product.
I used to write scripts and procedures, but no more!
Reason is: you save time. A lot of time. You pay few hunderes $ once for the product.
If you do it yourself, you waste half-days doing it properly.
A good tool for database compare is Comparenicus (www.compareniucs.com).
I'm using it for 6 months now and it saves me a lot of time.