Details
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Bug
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Status: Closed
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Major
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Resolution: Resolved
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v2.6.3
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None
Description
Hi Kylin Team:
I found a bug when I'm using PreparedStatement query.
Let me use table KYLIN_SALES to explain the scenario.
There is a SQL like:
select LSTG_FORMAT_NAME, sum(PRICE) from KYLIN_SALES where lower(LSTG_FORMAT_NAME) = 'fp-gtc' group by LSTG_FORMAT_NAME
In some cases, user doesn't know the LSTG_FORMAT_NAME is upper case or lower case, or they just want to query data ignoring cases.
So assume they use lower(LSTG_FORMAT_NAME) = 'fp-gtc', it's a function within the filter.
When I execute this SQL on Kylin web console, it can get the right result, but when I tried to execute it by PreparedStatement query on Postman, it threw InternalErrorException. 
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Root Cause
I debugged Kylin to find the root cause, it turns out when the filter contains function, compFilter.getColumn is null, and the compFilter.getFunction contains lower(LSTG_FORMAT_NAME), so that compFilter.getColumn().getType().isDateTimeFamily() will throw NullPointerException, that's the root cause for this 500 error.
Solution
I suggest to check nullable first before using compFilter.getColumn.
