如何返回按NULL和NOT NULL分组的记录? [英] How do I return my records grouped by NULL and NOT NULL?

问题描述

我有一个具有processed_timestamp列的表-如果记录已被处理，则该字段包含其处理的日期时间，否则为空.

I have a table that has a processed_timestamp column -- if a record has been processed then that field contains the datetime it was processed, otherwise it is null.

我想编写一个返回两行的查询:

I want to write a query that returns two rows:

NULL        xx -- count of records with null timestamps
NOT NULL    yy -- count of records with non-null timestamps

有可能吗?

更新:该表非常大，因此效率很重要.我可以只运行两个查询来分别计算每个总数，但是如果可以避免的话，我想避免两次击中该表.

Update: The table is quite large, so efficiency is important. I could just run two queries to calculate each total separately, but I want to avoid hitting the table twice if I can avoid it.

推荐答案

Oracle:

按nvl2(字段，"NOT NULL"，"NULL")分组

group by nvl2(field, 'NOT NULL', 'NULL')

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