Converting timestamp to epoch in snowflake - sql

I have timestamp in following format: "2022-03-08 17:11:59.901" , I want to convert them to UNIX/Epoch format up to milliseconds, somehow it only delivers till seconds part.
Is there anyway to do it?

If you have a string timestamp and you want to convert to EPOCH:
SELECT to_timestamp('2022-03-08 17:11:59.901') as ts,
date_part(EPOCH_MICROSECOND ,ts)

Related

How to convert the time format into YYYY:MM:DD (without hour and minutes)

I'm attempting to convert the time into a YYYY:MM:DD format. I have already truncated it from a timestamp format. However, with the trunc, I come up with this format (using Periscope):
Here is the date part of my query
You can try this:
SELECT FORMAT(your_date, 'yyyy:MM:dd')

Getting incorrect date when converting epoch to timestamp

I have a timestamp in epoch format like this: 1551187548876. If I convert this to a timestamp using https://www.epochconverter.com/, I get the correct time back.
However, if I convert it to time using PostgreSQL to_timestamp, I get the following:
select to_timestamp(1551187548876) from my_table;
51125-03-06 14:14:36+00
Question
How can I convert epoch 1551187548876 to a timestamp in PostgreSQL?
I assume that the epoch number you have is the number of milliseconds since the epoch, not the number of seconds, as customary.
Try dividing by 1000:
select to_timestamp(1551187548.876);
to_timestamp
----------------------------
2019-02-26 14:25:48.876+01
(1 row)

Converting only time to unixtimestamp in Hive

I have a column eventtime that only stores the time of day as string. Eg:
0445AM - means 04:45 AM. I am using the below query to convert to UNIX timestamp.
select unix_timestamp(eventtime,'hhmmaa'),eventtime from data_raw limit 10;
This seems to work fine for test data. I always thought unixtimestamp is a combination of date and time while here I only have the time. My question is what date does it consider while executing the above function? The timestamps seem to be quite small.
Unix timestamp is the bigint number of seconds from Unix epoch (1970-01-01 00:00:00 UTC). The unix time stamp is a way to track time as a running total of seconds.
select unix_timestamp('0445AM','hhmmaa') as unixtimestamp
Returns
17100
And this is exactly 4hrs, 45min converted to seconds.
select 4*60*60 + 45*60
returns 17100
And to convert it back use from_unixtime function
select from_unixtime (17100,'hhmmaa')
returns:
0445AM
If you convert using format including date, you will see it assumes the date is 1970-01-01
select from_unixtime (17100,'yyyy-MM-dd hhmmaa')
returns:
1970-01-01 0445AM
See Hive functions dosc here.
Also there is very useful site about Unix timestamp

bigQuery not supporting milliseconds timestamps

I have a value in my csv file for timetamp as '1522865628160'. When I load the data in bigQuery where this field type is timestamp, it saves the timestamp as '1522865628160000'. so when I query like
select * from <tablename> limit 1
it gives me error
Cannot return an invalid timestamp value of 1522865628160000000 microseconds relative to the Unix epoch. The range of valid timestamp values is [0001-01-1 00:00:00, 9999-12-31 23:59:59.999999]; error in writing field timestamp"
please help
I think the issue here is that you tried to load your UNIX timestamp data into a timestamp column in BigQuery. A BigQuery timestamp column is not the same thing as a UNIX timestamp. The latter is just a numerical value representing the number of seconds since the start of the UNIX epoch in 1970.
So the fix here would be to load your data into an INT64 (or INTEGER if you are using legacy) column. From there, you may convert your UNIX timestamp to a bona fide date or timestamp.
There is a MSEC_TO_TIMESTAMP() function which can convert an integer number of milliseconds since the UNIX epoch to a bona fide timestamp, e.g.
SELECT MSEC_TO_TIMESTAMP(1522865628160)
2018-04-04 11:13:48 UTC

Hive from_unixtime for milliseconds

We have a timestamp epoch column (BIGINT) stored in Hive.
We want to get Date 'yyyy-MM-dd' for this epoch.
Problem is my epoch is in milliseconds e.g. 1409535303522.
So select timestamp, from_unixtime(timestamp,'yyyy-MM-dd') gives wrong results for date as it expects epoch in seconds.
So i tried dividing it by 1000. But then it gets converted to Double and we can not apply function to it. Even CAST is not working when I try to Convert this double to Bigint.
Solved it by following query:
select timestamp, from_unixtime(CAST(timestamp/1000 as BIGINT), 'yyyy-MM-dd') from Hadoop_V1_Main_text_archieved limit 10;
The type should be double to ensure precision is not lost:
select from_unixtime(cast(1601256179170 as double)/1000.0, "yyyy-MM-dd hh:mm:ss.SSS") as event_timestamp
timestamp_ms is unixtime in milliseconds
SELECT from_unixtime(floor(CAST(timestamp_ms AS BIGINT)/1000), 'yyyy-MM-dd HH:mm:ss.SSS') as created_timestamp FROM table_name;
In the original answer you'll get string, but if you'd like to get date you need to call extra cast with date:
select
timestamp,
cast(from_unixtime(CAST(timestamp/1000 as BIGINT), 'yyyy-MM-dd') as date) as date_col
from Hadoop_V1_Main_text_archieved
limit 10;
Docs for casting dates and timestamps. For converting string to date:
cast(string as date)
If the string is in the form 'YYYY-MM-DD', then a date value corresponding to that year/month/day is returned. If the string value does not match this formate, then NULL is returned.
Date type is available only from Hive > 0.12.0 as mentioned here:
DATE (Note: Only available starting with Hive 0.12.0)