Re: general theory behind 'primary_key' & 'auto_increment' flags, and ON DUPLICATE KEY UPDATE ?

On Wed, Jul 15, 2009 at 4:40 PM, Govinda<govinda.webdnatalk@gmail.com> wrote: > > On Jul 15, 2009, at 7:37 AM, Bastien Koert wrote: > >> On Wed, Jul 15, 2009 at 9:21 AM, Govinda<govinda.webdnatalk@gmail.com> >> wrote: >>> >>> Reading docs..  I want to be sure of things...  have your verification of >>> my >>> understanding(s)- >>> >>> Does setting a mysql db column (say "myPrimarykeyID") with the >>> 'primary_key' >>> & 'auto_increment' flags totally negate the logic for ever having to use >>> ON >>> DUPLICATE KEY UPDATE in an INSERT? >>> >>> Or is it that I can do an INSERT with SET >>> myPrimarykeyID=someAlreadyExistingVal, a=1, b=2....  ON DUPLICATE KEY >>> UPDATE >>>  a=edited1, b=edited2 ... >>> >>> I am trying to learn/work out the mysql/php code that will allow me to >>> either create *or* edit a record, in one fell swoop. >>> >>> Thanks for any insight! >>> -Govinda >>> >>> -- >>> PHP Database Mailing List (http://www.php.net/) >>> To unsubscribe, visit: http://www.php.net/unsub.php >>> >> If that is the goal use the REPLACE INTO sql syntax >> >> You really don't want to allow duplicates in primary keys, that >> completely negates the usefulness of that key > > well isn't it that in order for the REPLACE INTO to replace the old row I > have to try and replace a row with an already existing uniqueID?  The same > thing I would do to cause the INSERT..  SET .. ON DUPLICATE KEY UPDATE to > kick in?  Don't both methods equally effectively 'prevent duplicate primary > keys from occurring'? > > -G REPLACE will do the same thing as an DELETE where KEY = and then an INSERT or just does an insert if the KEY is not present -- Bastien Cat, the other other white meat