Please give me idea now I compile all branch data

[mfa786]

Hi master
Sir I have 5 office In different city and one head office in Karachi all branch have same oracle system my question is how I get new data and compile for accumulative reporting

I want only new record and modify record not old record
Old record already I import

When I use oracle import and export tool that no give me right result
If xxx table exists in database then import tool not replace and no insert or no replace with previous data with new modify data

Such as
First time
V_no=897 have debit amount 3998 is Islamabad branch and i export form Islamabad and import in Karachi office

Next time
Islamabad office change v_no=897 debit amount with 76555 and add many new record
I export form Islamabad and import in Karachi office but system no change and not add new record in Karachi office

Please give me idea now I compile all branch data in head office only new record and modify record

Thanks

aamir