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Impala - Convert bigint to timestamp

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New Contributor

I've a table called "session" and it has a column 'conferencedatetime' with datatype as 'bigint'

 

I want to get the output of this column in a date/timestamp format (for e.g. 2018-01-01 01:00:00)  

 

But I'm not able to get the desired output when I tried with the 'from_unixtime' function. (it returns NULL as output)

 

Can you please advise what is the correct way to get the output ?

 

---------------------
select s.conferencedatetime as starttime from session s ;
1500778867943

 

select from_unixtime(s.conferencedatetime, "yyyy-MM-dd HH:mm:ss") as starttime from session s ;
NULL
--------------------------------

1 ACCEPTED SOLUTION

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New Contributor

Hi @AcharkiMed - Thanks for the response. But that query also returns NULL as the output.

 

But I got a resolution for the issue

 

select from_timestamp(CAST(CAST(s.conferencedatetime as decimal(30,0))/1000 AS timestamp), "yyyy-MM-dd HH:mm:ss.SSS") as starttime from session s

View solution in original post

5 REPLIES 5

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Master Collaborator

HI @VJM

You shold use the cast function:

select cast(s.conferencedatetime as TIMESTAMP) as starttime from session s;

Good luck.

avatar
New Contributor

Hi @AcharkiMed - Thanks for the response. But that query also returns NULL as the output.

 

But I got a resolution for the issue

 

select from_timestamp(CAST(CAST(s.conferencedatetime as decimal(30,0))/1000 AS timestamp), "yyyy-MM-dd HH:mm:ss.SSS") as starttime from session s

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New Contributor

I am inserting the data using below column,also myoutput table column has dataype timestamp.

But its not casting it into the timestamp.

 

from_timestamp(cast(T1.converted_start_dt as timestamp),'yyyy-MM-dd HH:mm:ss.SSSSSSSSS') start_dt

 

Please suggestsolution

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Expert Contributor

Hi @kunalkhadse11 ,

 

Can you share the sample data, the complete query and the actual, expected output?

 

Thanks

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Contributor

The same workaround worked for me too - also getting null when selecting from_unixtime(starttime). starttime is bigint. Is this a bug in Impala or ... ?

 

Also, in hive the following query normally works:

 

SELECT cast(starttime as TIMESTAMP) from dynatracelogs ORDER BY starttime desc LIMIT 100  

 

but in Impala it returns nulls. ....