This function disconnects the connection identified by the ConnectionName parameter. All other parameters are ignored.
If no ConnectionName parameter is specified in the string, the unnamed connection is disconnected. This is equivalent to the
embedded SQL DISCONNECT statement. The return value is TRUE if a connection was successfully ended. Error information is returned
in the SQLCA.
This function shuts down the database if it was started with the AutoStop=yes parameter and there are no other connections
to the database. It also stops the server if it was started with the AutoStop=yes parameter and there are no other databases