SQL Server Managment Studio and commit

Question

Suppose I had a table with a large number of records, I wanted to update all the record in that table using SQL Server managment studio 2008, I typed:

Update Table set col1 = val

It will take a while for this command to update all the records, now if I pressed stop excutioin, what exactly will happen, some records will be upodated and committed or non like I've never excuted that command?

Answer 1

it will be all or nothing, it is a set based operation SQL Server uses implicit transaction if an explicit one has not been started, this is a way to ensure ACID

so to answer your question if you stop it it will be in the same state as it was before you pressed ! or F5