Further tests reveal that one of the two applications discussed earlier generates empty fields when only one product is ordered.
进一步的测试发现，当只订购一种产品时，前述的两个应用程序之一会产生空字段。
2
If the number of tuples, calculated by using the Cartesian product, exceeds the set threshold; the NON EMPTY clause is applied to the query.
如果通过使用Cartesian产品计算的元组数超过设定的阈值，将NON empty子句应用于查询。
3
It's also more effective to offer visitors concrete arguments, situations and ideas of how a product or a service can be used instead of bombarding them with loud and empty ad-slogans.