Jonathan, I'm trying to write a script that checks for multiple entries on a table in a database. So far I've been plagued by MySQL errors. I'm fairly confident my scripting is ok (Then again, I've been wrong before.) I think moreover there might be some difficulty with my theory. Then again, I could try and do this with MySQL join statements. Any feedback would be appreciated. ... Warning: Supplied argument is not a valid MySQL result resource in /home/ufr2/underfoot-www/admin/dupeshows.html on line 51
I notice that others have addressed your PHP/interfacing issues... You asked about "theory". The current solution will require n+1 calls to the database (where there are n-rows in the local_shows table). That's quite 'expensive'. Which is likely to be the 'best tool for the job' - an external scripting language (PHP) or the RDBMS itself (MySQL)? Consider a 'MySQL-oriented' solution:- 1 if the two fields (show_date and venue) were made into a UNIQUE index, then the check would become superfluous because MySQL would ensure the situation never arose - at the cost of the time to perform the check/index insertion at every row INSERT or UPDATE (although you may gain a speed increase for certain SELECTS) 2 performing the existing PHP routine using SQL - you show only a list of 'duplicates' (and no DELETE), so: select show_date, venue, count(*) as freq from local_shows group by show_date, venue having freq>1 will give you what you have attempted to code thus far. (you may wish/need to juggle the sequence of show_date and venue to suit) Regards, =dn -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
