Learnt more from here. On Mon, Apr 7, 2008 at 9:22 AM, Baron Schwartz <[EMAIL PROTECTED]> wrote:
> Hi, > > On Wed, Apr 2, 2008 at 4:34 PM, Ben Roberts <[EMAIL PROTECTED]> > wrote: > > > > Hello, > > > > Does anybody have any info on cross-database joins? > > > > i.e. doing a join across various tables that are located inside > different > > databases (albeit on the same database server). > > > > I'm interesested in any potential pitfalls, limitations, and > performance > > issues. There doesn't appear to be much information about this on the > web > > (at least not that I can find so far). > > There are sometimes queries that are hard to write so MySQL doesn't > complain about an error, but this is not hard to avoid: > > http://www.xaprb.com/blog/2006/08/07/how-to-write-multi-table-cross-database-deletes-with-aliases-in-mysql/ > > > I'm using the InnoDB engine. Do foreign key constraints work across > > different databases too? > > FK constrraints work fine across databases. > > Regards > Baron > > -- > > Baron Schwartz, Senior Consultant, Percona Inc. > Tel: +1 888 401 3401 ext 507 > 24/7 Emergency Line +1 888 401 3401 ext 911 > Our Services: http://www.percona.com/services.html > Our Blog: http://www.mysqlperformanceblog.com/ > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: > http://lists.mysql.com/[EMAIL PROTECTED] > > -- I'm a mysql DBA in china. More about me just visit here: http://yueliangdao0608.cublog.cn
