Problems encountered in. NET Programming for beginners (8)

One CSProgram. Only one data is connected. Therefore, the connection is the same. The sqlconnection variable must be constantly closed.

The thread pool does not close this object. It is also found from the data pool.

What is the difference between this connection and I don't close it? Which method is better?

 If you are always using this database connection and frequently need to use database resources, you do not need to close the database connection before using it, however, if you do not use database resources for a long time, you can close the connection and re-connect when you need to use it again.