So can someone give me a working example of two database ATTACHed and a simple select using columns from a table in each database
On 13 August 2015 at 07:13, Chris Parsonson <z2668856 at gmail.com> wrote: > Now we get down to the first real problem that of the ATTACH. I have never > been able to get that to work. If I could have got the ATTACH to work I > probably would never have had to ask the synchronisation question. Although > I have never had to do it before in SQLite, I have worked a lot with SQL > Server doing synchronisation there > > On 13 August 2015 at 07:08, Simon Slavin <slavins at bigfraud.org> wrote: > >> >> On 13 Aug 2015, at 5:55am, Chris Parsonson <z2668856 at gmail.com> wrote: >> >> > The tables are very simple. They have a primary key, but no relationship >> > between tables in the sense that you mean. Synchronisation will be add >> new >> > rows, and update some rows, no deletions >> >> To access two different databases with one database connection, use the >> ATTACH command. >> >> Method 1 >> -------- >> >> To find rows which are in one table but not in the other, use EXCEPT >> >> SELECT primaryKeyColumn FROM databasea.myTable EXCEPT SELECT >> primaryKeyColumn FROM myTable >> >> In cases where a row has been updated with a new value in one column, how >> do you propose to decide which value is the 'right' one to put in both >> databases ? >> >> Method 2 >> -------- >> >> Ignore Method 1. In each copy of your database keep a log of all INSERT >> and UPDATE commands executed since the last 'synchronize': >> >> CREATE TABLE commandsSinceLastSynch (theCommand TEXT) >> >> To synchronise the two copies, play back the log for copy A to copy B and >> the log for copy B to copy A. >> >> Simon. >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users at mailinglists.sqlite.org >> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >> > > > > -- > Chris Parsonson > 083 777 9261 > -- Chris Parsonson 083 777 9261
