If you move your tables to SQL Server and link them back to Access, most of your Access queries should still work, especially the simple ones. Access is really good at handling linked tables from SQL Server behind the scenes, and most of your select queries, forms, and reports will keep running as usual. Where you might run into issues is with more complex queries, especially ones that use Access-specific features like domain aggregate functions (DLookup, DSum), user-defined functions in VBA, or some of the more unusual Access SQL syntax. Those things don't always translate directly to SQL Server.

Also, action queries like append, update, or delete sometimes need tweaking, especially if your SQL Server tables use things like triggers or constraints, or if you run into permission differences. If you ever want to run queries directly on SQL Server (using stored procedures or SQL scripts), then yes, you'll need to rewrite those in T-SQL. But just switching the back-end tables and linking them into Access doesn't force you to rewrite everything unless you hit specific compatibility snags.

In short, you shouldn't expect your database to just stop working, but it's a good idea to test everything thoroughly after upsizing to catch any queries that need adjustment. If you run into any particular queries that break after moving to SQL Server, post them here and I can help you troubleshoot. And as always with big changes like this, make sure you have a backup before you start experimenting.

Thanks Captain.