In the last episode (Mar 30), Ian P. Christian said: > Brent Baisley wrote: > >No, you can't assure the same data will be addressed without at > >least including an order by. Even then you would need to make sure > >that the first X records in the order would not change. For > >instance, if you order by entered_date DESC, then the data set would > >change because any new records would get included in the LIMIT. > > Will it not always use the natural order of the table in > selects/deletes, and therefore return results in the order in which > they were inserted?
If you know that no-one else has inserted or deleted records between your two commands, the commands will return the same records. To be completely safe, you would want to use innodb tables, then select only the primary key of the 50,000 records you're interested in, using the "FOR UPDATE" keyword (to keep others from modifying those records while you're doing the move). Then "INSERT INTO newtable SELECT * FROM oldtable WHERE primarykey in ( your 50,000 keys )", then "DELETE FROM oldtable WHERE primarykey in ( your 50,000 keys )", then COMMIT, which will cause your insertions and deletions to be truly atomic. -- Dan Nelson [EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]