Yes it would, but if it didn't meet the criteria then it would just leave the value as is. The person asking the question stated that this was for a school, that would probably be a few thousand students at most.
Plus I gave the alternative of a table join which would be more restrictive. Steve -----Original Message----- From: Byron Mann [mailto:[email protected]] Sent: Thursday, February 06, 2014 11:24 PM To: sql Subject: Re: sql query help Need to update that, the Case statement would update every row where gom = 'maze'. Even those rows not needing to be updated. Byron Mann Lead Engineer & Architect HostMySite.com On Feb 6, 2014 11:17 PM, "Byron Mann" <[email protected]> wrote: > Depending on your table size, indexing and number of rows actually being > updated, it may be better to just wrap all the updates into a transaction. > > BEGIN TRAN; > > UPDATE...... > UPDATE...... > UPDATE...... > .... > COMMIT TRAN; > > The case statement example may not be optimal, as it will update every row > unnecessarily. Not nice if you have a million row table and only need to > actually update 30 rows. > > Multiple OR statements is probably better, as you will be restricting the > update to the required rows, but might be hard to read for debugging. Plus > too many ORs and performance may be more optimal with multiple updates. > > I usually find the simple the better. > > Byron Mann > Lead Engineer & Architect > HostMySite.com > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Order the Adobe Coldfusion Anthology now! http://www.amazon.com/Adobe-Coldfusion-Anthology/dp/1430272155/?tag=houseoffusion Archive: http://www.houseoffusion.com/groups/sql/message.cfm/messageid:3541 Subscription: http://www.houseoffusion.com/groups/sql/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/groups/sql/unsubscribe.cfm
