I would do update SQL on a copy of your database database to ensure everything is working correctly. Then when you do your live update you can create a second set of queries to find the ones you didn't update. To do this, save the primary keys of the table in question and then use those as a subselect for your second query. You would do something along the lines of the following:
Select field1, field2 from table1 where primarykey not in (Select primarykey from savedupdatedtable);
Good Luck!