hive 中没有显示 String NULL 数据的结果

Question

I have an external table in hive which was loaded with some NULL data.

None of the below queries are returning any results:

select * FROM  db.table where bankrupt IS NULL;

select * FROM  db.table where bankrupt = '';

select * FROM  db.table where bankrupt = ' ';

But select DISTINCT length(bankrupt) FROM db.table; Is returning value 1.

Sample data: (provided by client) 295.12|31/12/2021| | | 295.12|31/12/2021| | |

Bankrupt is the last column.

Answer 1

select DISTINCT length(bankrupt) FROM  db.table;

If what you said is true, and this row returns only 1 value, it means that either you only have only one single defined value. Or you only have null values, neitherless. If you are sure there is null values, maybe is just a tiny syntax inconvenience. Because your line of code is correct

SELECT * FROM DF WHERE bankrupt IS NULL;