// Create connection using windows authentication.
SqlLibraryConnection connection = new SqlLibraryConnection("serverName", "database", true);

// Path to the created connection file.
string path = connection.ConnectionPath;

// Using this connection you can connect project to the library.
Project project = ...
project.ConnectToLibrary(connection):

// If you do not want to use windows authentication, you must specify userName and password:
// 1.) When creating a connection (only once):
connection = new SqlLibraryConnection("serverName", "database", "user name", "password");
project.ConnectToLibrary(connection);

// 2.) When connecting to the library (always when connecting to the library):
connection = new SqlLibraryConnection("serverName", "database", false);
project.ConnectToLibrary(connection, "user name", "password");