在Cassandra中，如何在将列值保留为空的情况下以列名保存数据？ [英] In Cassandra, how is it possible to save data in a column name while leaving the column value empty?

问题描述

我已经看到它被写成多个来源，对于Cassandra来说，将数据存储在列名称中而将列值保留为空是完全正常的。我不确定我是否完全理解这种可能性。有人可以用最好的示例模式对此进行更多说明吗？

I've seen it being written in multiple sources that it is perfectly normal, with Cassandra, to store data in the column name, while leaving the column value empty. I'm not sure I completely understand how that's possible. Can anyone throw more light on this, preferably with an example schema?

推荐答案

不，不再。这曾经是可能的。它需要旧的（3.x之前的版本的存储引擎）并使用基于Thrift的API。但是，使用CQL（和 new 存储引擎）构建的表要求所有列都预先定义，并且不允许在运行时使用（至少，与Thrift的方式不同）。

No, not any more. This used to be possible. It required the old (pre-3.x storage engine) and use of a Thrift-based API. But tables built with CQL (and the new storage engine) require all columns to be defined-up front, and do not allow it at runtime (at least, not in the same way that Thrift did).

上面提到的文章的日期为2015年，当时仍然可行。 Apache Cassandra是其中一种在短时间内发生了很大变化的技术，它们很快就会过时，一旦被接受的做法和建议就会过时。

The article referenced above is dated 2015, when this was still possible. Apache Cassandra is one of those techs that has changed a lot in a short time, quickly out-dating once accepted practices and recommendations.

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