It may be true that "some DBMSs" physically store rows in whatever order you speicfy; however, this is a MySQL list, and MySQL does not do this (InnoDB anyway).
For example, take a table with 10,000,000 rows and run a simple select on it: Database changed mysql> SELECT id FROM trans_item LIMIT 1\G *************************** 1. row *************************** id: 8919552 1 row in set (0.08 sec) mysql> SELECT id FROM trans_item ORDER BY id ASC LIMIT 1\G *************************** 1. row *************************** id: 8441275 1 row in set (0.08 sec) Sure, the first query may always return that ID number; however, it may not. On Tue, Aug 18, 2009 at 2:31 PM, Martijn Tonies <m.ton...@upscene.com>wrote: > > > To further emphasize this point: A table has no order by itself, >> > > That's not entirely true ;-) Records are stored in some kind of physical > order, some DBMSses implement clustered keys, meaning that the > records are stored ascending order on disk. > > However... > > and you should make no assumptions about the order of rows you will get >> back in a select statement, unless you use an ORDER BY clause. >> > > This is correct in that a -result set- does not have an "order" defined > unless you specify an ORDER BY clause. > > With regards, > > Martijn Tonies > Upscene Productions > http://www.upscene.com > > Download Database Workbench for Oracle, MS SQL Server, Sybase SQL > Anywhere, MySQL, InterBase, NexusDB and Firebird! > > Database questions? Check the forum: > http://www.databasedevelopmentforum.com > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/mysql?unsub=joh...@pixelated.net > > -- ----------------------------- Johnny Withers 601.209.4985 joh...@pixelated.net
