In the last episode (May 04), Hendro Suryawan said: > Hi all, > I found something strange with calculate field query in MySQL 5. > > My base table structure like this : > CREATE TABLE `BrgIn2` ( > `Qty` decimal(10,3) NOT NULL default '0.000', > `Price` decimal(19,4) NOT NULL default '0.0000', > `Kurs` decimal(10,4) default NULL > ) ENGINE=MyISAM DEFAULT CHARSET=latin1 > > Create Table testig Select PO,BrgId,Qty,Price,Kurs, Qty*Price*Kurs AS > Amount from BrgIn2 > > Result in MySQL 4.1x > > CREATE TABLE `testig` ( > `Qty` decimal(10,3) NOT NULL default '0.000', > `Price` decimal(19,4) NOT NULL default '0.0000', > `Kurs` decimal(10,4) default NULL, > `Amount` double(21,4) default NULL > ) ENGINE=MyISAM DEFAULT CHARSET=latin1 > > > Result in MySQL 5.0.20a > > CREATE TABLE `testig` ( > `Qty` decimal(10,3) NOT NULL default '0.000', > `Price` decimal(15,4) NOT NULL default '0.0000', > `Kurs` decimal(10,4) default NULL, > `Amount` decimal(35,11) default NULL > ) ENGINE=MyISAM DEFAULT CHARSET=latin1 > > The result field is different size. Is it normal behaviour for MySQL 5 > or bug? Because i have trouble with this behaviour in my apps. I use > Delphi 5/6 for my development tool.
MySQL 5's result is correct. MySQL 4 converts "decimal" values to "double" when doing math, where MySQL 5 has a true fixed-point math package to process "double" values. http://dev.mysql.com/doc/refman/5.0/en/precision-math.html -- Dan Nelson [EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
