Yes, in perl is OK, but in MySQL it is not really ok. Perl regular expressions use ^ and $ for specifying the start and end of the string while MySQL like operator doesn't
For example, if $string = 'a', // with match in perl, but /^$/ won't match. MySQL like operator could use '%' for matching everything but it don't have any way to match only the empty string, because it doesn't have a way of specifying the start and end of the string. Teddy ----- Original Message ----- From: "Josh Chamas" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: <mysql@lists.mysql.com> Sent: Sunday, September 11, 2005 16:18 PM Subject: Re: Behaviour of like expression > [EMAIL PROTECTED] wrote: > > Hi all, > > > > I've got a question. We were testing something on our mysql server ( > > 4.0.21) with MyISAM tables. > > > > When we executed the query "select * from people where name like '';" we > > expected the same results as "select * from people where name='';" but it > > didn't. > > > > The like function returned everything instead of only the people without a > > name. Is this known (and correct) behaviour? It does not sound logical to > > me. I couldn't find anything about it on the mysql website. > > > > Usually, pattern matching done where a pattern is nothing matches everything. > > Use LIKE for pattern matching, and = for equivalency. > > I don't know what the ANSI SQL spec says here, and whether our behavior > is correct there, but this behavior makes sense to me at least. I would > expect similar behavior from perl, for example: > > $ perl -e 'my $a = qw(a); print $a =~ //;' > 1 > > Regards, > > Josh > -- > Josh Chamas > Director, Professional Services > MySQL Inc., www.mysql.com > Get More with MySQL! www.mysql.com/consulting > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
