Ms Sql Server Express Portable _hot_ -

E:\PortableSQL\ ├── Data\ │ ├── MyDatabase.mdf │ └── MyDatabase_log.ldf ├── Scripts\ │ ├── start.bat │ ├── stop.bat │ └── attach.sql └── Tools\ └── SSMS.exe (optional, portable version of SSMS exists)

LocalDB is the closest official version to a portable SQL Server. It is a lightweight execution mode of SQL Server Express that runs as a user process rather than a system service. ms sql server express portable

If your goal is a database that requires absolutely no installation or runtime on the host machine, consider these "In-Process" alternatives: E:\PortableSQL\ ├── Data\ │ ├── MyDatabase