'Checks if a where statement given exists
If there is no output, it will raise an assertion error
Usage:
Check if exists  s3db.auth_user.id > 100
False
Check if exists  s3db.auth_user.id > 10
True'

def check_if_exists(self, statement):

    output = self.query_and_return_the_first_row_where(statement)
    if (not output):
        raise AssertionError(("Expected    to    have    have    at    least    one    row    from    '%s'                                                                    but    got    0    rows." % statement))
