Database is being used by another process … but what process?

Question

I have written a very small C# program, that uses a very small SQL Server database, purely for some learning & testing purposes. The database is used in this one new pro

Answer 1

The most likely options:

1. A previous (crashed) instance of your program
2. Visual Studio (with a Table designer open or something similar)

You can check 1) with TaskManager and 2) by looking in Server Explorer. Your db should show a small red cross meaning 'closed'.

And you should rewrite your code to close connections ASAP. Use try/finally or using(){ } blocks.