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**Checking For Modified Rows**


I need to replicate data (approx. 10,000 records) from a mySQL database into
a different (non mySQl) database automatically on a regular basis. I have no
control over the mySQL server (apart from allowing ODBC access) so I cannot
modify any tables or enable replication etc...

My initial thoughts on how to do this are:

1. Execute a query similar to the following to retrieve a list of rows and a
unique checksum:
SELECT id, md5(id + "_" + name + "_" + path + "_" + comments) from mytable
2. Lookup each id in my local database
a) If it doesn't exist add the id and checksum to my local database and add
the record into my actions database as a record to replicate.

b) If it exists and the checksums are different update my local database and
add the record into my actions database as a record to replicate.

REPEAT step 2 for all records

At this point the actions database would contain a list of all records which
have been inserted or modified. The last step would be to determine which
records have been deleted. My thoughts where to mark each record in my local
database when a match occurred. Any records in my local database which were
not marked as matched would be added to the actions database as records to
delete and then deleted from my local database.
Any thoughts / feedback on this would be appreciated.

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Jul 19 '05 #1
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