That sounds like quite a bit of work. First up, changing the tag names will change their addresses in OPC, so each tag path in FactorySQL or SQLTags will need to be modified. In both cases the easiest way may be with CSV export/import. In FactorySQL, you’ll be changing the Item Path property of each item, in SQLTags it’s the OPC Item Path property in the meta props table. Using CSV will hide all of that, but I just wanted to point it out.
Changing the database column names… sounds like a bad idea. First off, you if have sets of data that are the same for each line, I would just add a “line number” column and query off that. If not, and you’re only trying to change your column names for display purposes, I would just add “as” aliases to the queries. Basically, I would do whatever I could to not change the column names, because it’s going to be a lot of work, and probably going to break lots of things for a while until you get everything sorted out.
That said, if you really want to, you just need to change the “field names” in your groups, and then use some DB Administration tool to actually change the columns in the db. Unfortunately FactorySQL can’t do this for you. SQLTags won’t be affected, because no columns are actual named off of the tag names.