Thanks Sebastian,

The samething I thought, i will maintain a log file to keep track of record changes at both the ends, and when the data is sent/received logs will be compared and latest modification stays.

If I allow changes at one location only, I belive my job will be easier.

Another question is how to transfer data, among two?? I can use OLE DB or ODBC to update remote database, however will it take long time, and is it advisable to directly run code at client location?

Alternatively, is it a better idea to FTP or Email the log file and administrator at other site can manually download and synchronize databases?

Please comment.

Cheers!!




>Hi!
>
>>>
>Singapore and Indonesia maintains their own databases. Now we want to merge the information. In such a way that Indonesia can update their information locally and later upload to Singapore server, where the data will be merged to Singapore database.
><<
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>There is no native way in VFP to handle this case!
>
>Some ideas:
>- write logfiles to collect the informations about changed/created/deleted records
>- based on this log files create a related subset of all changed data and send it to the other site
>- process the logfile and the releated data
>
>Be aware of some important things:
>- If both sides changed a record, you need some rules to handle this ("the last wins" or other rules)!
>- What about dealing with more than one change of one record between two merges (modify a record, modify it again, then deleting...)?
>- What about dealing with primary keys?
>- What about dealing with changes in different child records of a parent record to ensure the business integrity of your data?
>
>Concluiso: Be sure you will have a hard, hard job (I did such a job some month ago for a data model with about 100 tables - and it tooks me more than half a year of work to handle all the needed stuff!).