Should I close or dispose a SqlConnection registered as InstancePerRequest?

I'm registering a new instance of System.Data.SqlClient.SqlConnection as InstancePerRequest in Autofac, and I .Open() the connection in the registration.
I use it in multiple repository services which implement IDisposable.
I'm not sure whether I need to .Close() the connection or .Dispose() it.
Every source or information says different things and it made me pretty confused.
I would appreciate any clarification on this matter and reliable sources of information.
Thanks1

Solution

When using SqlConnection, it's important to manage the connection properly to avoid resource leaks and potential security issues. Here are some recommendations: Use the using statement to ensure that the SqlConnection object is properly disposed of when it's no longer needed.

When using SqlConnection with Autofac, you should register the connection as a per-request instance and open the connection in the registration. You don't need to close the connection explicitly; Autofac will dispose of the object when the request is completed.

Calling Dispose on the SqlConnection object will close the connection if it's still open, so you don't need to call Close explicitly.

Here's an example registration in Autofac:

builder.Register(c => {
    var connectionString = ConfigurationManager.ConnectionStrings["MyConnection"].ConnectionString;
    var connection = new SqlConnection(connectionString);
    connection.Open();
    return connection;
}).InstancePerRequest();

And here's an example usage in a repository service:

public class MyRepository : IDisposable {
    private readonly SqlConnection _connection;

    public MyRepository(SqlConnection connection) {
        _connection = connection;
    }

    public void Dispose() {
        // No need to explicitly close the connection; it will be disposed of by Autofac
    }
}

For further reading, you can refer to the following resources: