'Processes a sql template
>>> sql = "SELECT \'{{ datetime(2017, 1, 1).isoformat() }}\'"
>>> process_template(sql)
"SELECT \'2017-01-01T00:00:00\'"'

def process_template(self, sql, **kwargs):

    template = self.env.from_string(sql)
    kwargs.update(self.context)
    return template.render(kwargs)
