SQL Server and connection loss in the middle of a transaction

If you lose the connection in the middle of a transaction you can no longer reenter this transaction from a different connection. If the connection is dropped, SQL Server will rollback any uncommitted transactions automatically. So if this happens, simply reconnect and you will find your database at the same state it was before starting the transaction (assuming of course there aren't other users that might have changed it in between.

Generally, any break in the transaction will be rolled back. Whether the client disconnects, CommandTimeout or the server restarts itself.

This is Atomic in ACID

The ability to "pick up" a transaction where it left off does not make sense

• other transactions that happen/the transaction LSN will be out of order
• internal structures are changed as part of a write (indexes etc)/the database is inconsistent