On 11 Jul 2009, at 5:16am, Bill Harris wrote: > Is there a way to update / synchronize an sqlite database between two > sites successfully using email?
It's not the email that's the problem, it's the synchronisation. Suppose your database is a list of customers. There are two copies: one at site A, one at site B. Simple problem: At site A, someone updates a phone number. At site B, someone updates the same phone number to a different value. What should happen when the copies are synchronised ? Isn't one of those people going to be furious that their change was lost ? More complicated problem: At site A, someone deletes the record for a particular customer: he heard they went out of business. At site B, someone updates the phone number for that customer: she was given the phone number for the accounting company involved in the winding up. How do you synchronise those two copies ? If you just follow the transaction journal in the order the events happened, you end up trying to update a record that doesn't exist. If you can work out a consistent way to solve problems like that, synchronisation is just a matter of programming: every so often each site sends its copy of the database to all other sites, and a program is run to reconcile the two. So you might sit down and work out that, due to the way your two sites do business: one record could only ever be updated/deleted by one of the sites. But you have to know how your organisation works or changes will get lost. Problems like this are why companies use web-facing database systems: so that everyone is looking at the same data at the same time. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
