How to concatenate empty strings with concat () and concat_ws in Hive

This article mainly introduces the Hive concat () and concat_ws how to concatenate empty strings, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let Xiaobian take you to understand.

Concat (): if empty exists, null is returned:

Hive > select concat ('cd','1'); OKcd1Time taken: 0.461 seconds, Fetched: 1 row (s) hive > select concat (' cd',1); OKcd1Time taken: 0.066 seconds, Fetched: 1 row (s) hive > select concat ('cd',null); OKNULLTime taken: 0.053 seconds, Fetched: 1 row (s) hive > select concat (' null','cd'); OKnullcdTime taken: 0.06 seconds, Fetched: 1 row (s) hive > select concat (null,'cd') OKNULLTime taken: 0.056 seconds, Fetched: 1 row (s) hive >

Concat_ws: if empty exists, return non-empty stitching:

Hive > select concat_ws ('_,'); OKa_c_v_dTime taken: 0.06 seconds, Fetched: 1 row (s) hive > select concat_ws ('_', null,'c','v','d'); OKc_v_dTime taken: 0.047 seconds, Fetched: 1 row (s) hive > select concat_ws ('_', null,'c',null,'d') OKc_dTime taken: 0.053 seconds, Fetched: 1 row (s) hive > select concat_ws (null,'a','c','v','d'); OKNULLTime taken: 0.055 seconds, Fetched: 1 row (s) hive > hive > select concat_ws ('_', null,'c',null); OKcTime taken: 0.072 seconds, Fetched: 1 row (s) hive > select concat_ws ('_', null,null,null) OK Time taken: 0.049 seconds, Fetched: 1 row (s) hive > Thank you for reading this article carefully. I hope the article "how to concatenate empty strings between concat () and concat_ws in Hive" shared by the editor will be helpful to you. At the same time, I hope you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!