问题描述
我将开始在项目中使用MongoDB并进行以下观察: 日期"必须是有效的时间点，并且不能为NULL .
对于MongoDB，我们不能存储空日期，所以我猜测最好的办法是从文档中排除日期字段.
例如，如果我有一个汽车"文档和一个名为" date_sold "的字段.如果尚未出售汽车，则只需从文档中排除此字段即可.汽车售出后，我可以添加"date_sold"字段.
通过上述操作，我假设我可以查询已售或未售汽车的记录.这是在MongoDB中处理空"或空日期的推荐方法吗?
P.S.我感到困惑的原因是，由于SQL具有模式，所以日期或日期时间字段可以存储为NULL，但是在MongoDB中，日期"字段不能为NULL，并且必须是有效的时间点.
在MongoDB中，没有日期存储时省略date字段可以正常工作，这不同于传统的SQL数据库，在传统的SQL数据库中，每个记录/文档都必须遵循相同的架构. /p>
您可以使用 $ exists 来测试值在那个领域.
I will begin using MongoDB in a project and made the following observation: ‘Date’ must be a valid point in time, and cannot be NULL.
With MongoDB, we cannot store a NULL date, so I am guessing that the best thing to do is to simply exclude the date field from our document.
For example, if I have a ‘car’ document and a field named ‘date_sold’. If the car has not been sold yet, I simply exclude this field from the document. Once the car sells, I can add the 'date_sold' field.
By doing the above, I am assuming that I can query records for cars sold or not sold. Is this a recommended way to handle "empty" or null dates in MongoDB?
P.S. My confusion stems from the fact that since SQL has a schema, date or datetime fields can be stored as NULL, but in MongoDB, a ‘Date’ field cannot be NULL and must be a valid point in time.
Omitting the date field when there is no date to store works fine in MongoDB unlike a traditional SQL database where every record / document has to follow the same schema.
You can use $exists to test for a value in that field.
这篇关于MongoDB“空"或NULL日期的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！