如果该列包含空值，如何从Hive表中获取列名？

Question

我尝试了以下查询，这些查询只给出空值的计数，我需要的是进行空检查并返回列名。

select count(*)-count(columnA), count(*)-count(columnB) from table;
select count(*) from table where columnA is null;

Answer 1

您也可以

SELECT 
  SUM(IF(columnA is NULL,1,0)) as canulls,
  SUM(IF(columnB is NULL,1,0)) as cbnulls 
FROM table;

这也将为您提供每列的空字段数。