Have you considered NOT comparing dates as strings but rather as date values? That will avoid the use of CONCAT() completely.
SELECT * FROM sampletable WHERE datefield >= '1999-01-12' and datefield <'1999-02-01' This example query will get all of the records from sampletable that were entered after January 11th and before February 1st. It will also be **very** fast if the column "datefield" is indexed. Shawn Green Database Administrator Unimin Corporation - Spruce Pine Alfredo Cole <[EMAIL PROTECTED]> wrote on 10/11/2004 09:43:14 AM: > Hi: > > I have a problem in that all statements that include concat execute very > slowly. For instance, if I have three fields in string format that represent > a year, month and day, and want to issue a select like: > > select * from cxcmanpag where contact > (year,month,day)<=stringYear+stringMonth+stringDay (simplified), then it will > take a long time, againts a table with only around 100,00 records. If I > rewrite the statement to read: > > select * from cxcmanpag where year<=stringYear and month<=stringMonth and > day<=stringDay, it will execute considerable faster, but will not produce the > same results. > > I have looked in the manual, and also read High Performance MySQL > from Zawodny > and Balling, and MySQL from Paul Dubois, but none of them seem to address > this issue. > > Can somebody point me to a URL or book that I should be reading to improve, > this, or how to avoid using concat altogether? > > Thank you. > > -- > Alfredo J. Cole > Grupo ACyC > www.acyc.com - www.clshonduras.com - SolCom > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] >
