Ok as dumb as this might sound, I forgot how to update multiple records in a single table based on a select from another table.
For example I have a table I backed up and made changes to a live table and therefor they are the same structure and lets say I made a mistake and would like to revert back the changed data prior (assuming I did not do a begin tran), I would like perform an update and compare the id number to be the same in the live table as the backed up table. I know this code I am writing below is not a working peice of work but it was something i thought in my head to get started with.
SET mycol = (select mycol from myothertable where active = 'y' and currentrevision = 'y')
where mytable.myid = myothertable.myid