Yes. It only reports the changed rows. Regards,
Jerry Schwartz Global Information Incorporated 195 Farmington Ave. Farmington, CT 06032 860.674.8796 / FAX: 860.674.8341 > -----Original Message----- > From: Jesse [mailto:[EMAIL PROTECTED] > Sent: Monday, April 02, 2007 4:16 PM > To: MySQL List > Subject: UPDATE / not UPDATE?? > > When I run the query: > > UPDATE InvHead I > JOIN (SELECT InvNo,Sum(Rate + CASE WHEN AttendingAcademy=1 > THEN 30 ELSE 0 > END) AS InvTot > FROM Participants P GROUP BY InvNo) AS PartSum ON > PartSum.InvNo=I.InvNo > SET I.Total=PartSum.InvTot > WHERE (I.InvoiceType='CL' OR I.InvoiceType='CSS') AND > I.RegFinishedDate IS > NOT NULL > > It initially updates several rows. However, when I run it > again, it updates > no rows at all. If I then go in and manually change the Total to an > incorrect value, then run it again, it updates that one row. > Does MySQL > check a value before updating it, and if it is the same as > the value that > it's updating it with, it doesn't bother updating it again? > > Thanks, > Jesse > > > -- > 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]
