and parameters are not displayed if None, reducing confusion for
error messages that weren't related to a statement. The full
module and classname for the DBAPI-level exception is displayed,
making it clear that this is a wrapped DBAPI exception. The
statement and parameters themselves are bounded within a bracketed
sections to better isolate them from the error message and from
each other.
fixes#3172
debug logging message would not emit if the logging were set up using
``logging.setLevel()``, rather than using the ``echo_pool`` flag.
Tests to assert this logging have been added. This is a
regression that was introduced in 0.9.0.
fixes#3168
Mike Bayer