Yifei Wu created KYLIN-4041:
-------------------------------
Summary: CONCAT NULL not working properly
Key: KYLIN-4041
URL: https://issues.apache.org/jira/browse/KYLIN-4041
Project: Kylin
Issue Type: Improvement
Reporter: Yifei Wu
Assignee: Yifei Wu
to support SQL 'concat' function, Kylin introduces a UDF named ConcatUDF.
but the NULL case cannot deal with correctly, like the below sql:
```
select
concat(meta_categ_name, CAST(null as VARCHAR)) as c1,
concat(meta_categ_name, ' Catagory') as c2
from test_kylin_fact
left JOIN edw.test_cal_dt as test_cal_dt
ON test_kylin_fact.cal_dt = test_cal_dt.cal_dt
left JOIN test_category_groupings
ON test_kylin_fact.leaf_categ_id = test_category_groupings.leaf_categ_id AND
test_kylin_fact.lstg_site_id = test_category_groupings.site_id
left JOIN edw.test_sites as test_sites
ON test_kylin_fact.lstg_site_id = test_sites.site_id
where meta_categ_name = 'Computers'
group by meta_categ_name
order by meta_categ_name
limit 1
```
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
