So the title is not really what the post is about. A bit misleading.

As the others already pointed you to DBI to connect to M$ SQL Server, I assume you will need to get acquainted with DBI/DBD syntax anyway, and reading from CSV - though fast and simple with Text::CSV and/or Text::CSV_XS - would be easiest to do with DBD::CSV. Just open two database handles from the same script and on you go.

FWIW, Postgres and MariaDB also run fine on Windows, and those are free and OpenSource.