Re: MySQL and table locking

Hello Jack, On 19-May-00 12:30:20, you wrote: > A better solution is this: >CREATE TABLE counters > ( > u int unsigned NOT NULL, > c int unsigned NOT NULL, > UNIQUE(u) > ); > Then, the individual counter could be implmented this way: >UPDATE counters SET c=c+1 WHERE u=236; >SELECT c FROM counters WHERE u=236; I don't see why this is a better solution. Locking tables is always a risky thing to do and should be avoided if possible. Not only you may risk to deadlock database connections but you will be also will be slowing them down. You'd better stick to auto-increment tables because AFAIK that's the only atomic incrementing and read operation that MySQL can perform. If only it supported transactions or stored procedures, things could be much different. FYI, auto-increment tables are used to emulate sequences (that MySQL doesn't support natively as well) under Metabase - a PHP database abstraction package. Look here for more information: http://phpclasses.UpperDesign.com/browse.html/package/20 Regards, Manuel Lemos Web Programming Components using PHP Classes. Look at: http://phpclasses.UpperDesign.com/?user=mlemos@acm.org -- E-mail: mlemos@acm.org URL: http://www.mlemos.e-na.net/ PGP key: http://www.mlemos.e-na.net/ManuelLemos.pgp --