Today, when deleting a database, an error kept occurring, roughly meaning: This database is in single-user mode and is still connected, so it cannot be deleted (even if SQL Server is stopped and restarted).
After searching on Baidu, I found a solution, which is backed up here:
First, create a stored procedure in the master database to kill all connections, and then call it using:
After executing, you can perform operations on the database.