Many thanks to you all, I really appraciate your helpfulness, Danilo
2013/4/26 Clemens Ladisch <[email protected]> > Hick Gunter wrote: > > Actually "CROSS" just forces SQLite to use the tables in the order > > specified. > > This is an SQLite optimization extension. I used CROSS because this is > the only explicit join type where standard SQL allows to omit the join > expression. > > When using CROSS where standard SQL allows it (for an actual cartesian > product), the table ordering does not really matter for optimization > purposes because the DB has to do two nested full table scans anyway. > > > It is the LEFT join that creates the rows where there is no match on > > the right hand side. > > It is the CROSS join that creates the rows where there is no appx > record. The LEFT join just does not filter out those. > > > Regards, > Clemens > _______________________________________________ > sqlite-users mailing list > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
