a boolean value should only contain two values, true or false, but is it correct? usually people assume so, but sometimes miss the fact that there could be the absence of the value all-together....
本文讨论了布尔值和数据库中的null值，重点介绍了在postgresql数据库中使用null值的方法和教训。文章强调了正确处理null值的重要性。
