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From Kevin Mellott <kevin.r.mell...@gmail.com>
Subject Re: how to covert millisecond time to SQL timeStamp
Date Tue, 02 Feb 2016 03:44:54 GMT
I've had pretty good success using Joda-Time
<http://www.joda.org/joda-time/index.html> for date/time manipulations
within Spark applications. You may be able to use the *DateTIme* constructor
below, if you are starting with milliseconds.

DateTime

public DateTime(long instant)

Constructs an instance set to the milliseconds from 1970-01-01T00:00:00Z
using ISOChronology in the default time zone.
Parameters:instant - the milliseconds from 1970-01-01T00:00:00Z

On Mon, Feb 1, 2016 at 5:51 PM, Andy Davidson <Andy@santacruzintegration.com
> wrote:

> What little I know about working with timestamps is based on
> https://databricks.com/blog/2015/09/16/spark-1-5-dataframe-api-highlights-datetimestring-handling-time-intervals-and-udafs.html
>
> Using the example of dates formatted into human friend strings ->
> timeStamps I was able to figure out how to convert Epoch times to
> timestamps. The same trick did not work for millisecond times.
>
> Any suggestions would be greatly appreciated.
>
>
> Andy
>
> Working with epoch times
> <http://localhost:8888/notebooks/sparkTimeSeriesExperiments.ipynb#Working-with-epock-times>
>
> ref: http://www.epochconverter.com/
>
> Epoch timestamp: 1456050620
>
> Timestamp in milliseconds: 1456050620000
>
> Human time (GMT): Sun, 21 Feb 2016 10:30:20 GMT
>
> Human time (your time zone): 2/21/2016, 2:30:20 AM
>
>
> # Epoch time stamp example
>
> data = [
>
>   ("1456050620", "1456050621", 1),
>
>   ("1456050622", "14560506203", 2),
>
>   ("14560506204", "14560506205", 3)]
>
> df = sqlContext.createDataFrame(data, ["start_time", "end_time", "id"])
>
> ​
>
> # convert epoch time strings in to spark timestamps
>
> df = df.select(
>
>   df.start_time.cast("long").alias("start_time"),
>
>   df.end_time.cast("long").alias("end_time"),
>
>   df.id)
>
> df.printSchema()
>
> df.show(truncate=False)
>
> ​
>
> # convert longs to timestamps
>
> df = df.select(
>
>   df.start_time.cast("timestamp").alias("start_time"),
>
>   df.end_time.cast("timestamp").alias("end_time"),
>
>   df.id)
>
> df.printSchema()
>
> df.show(truncate=False)
>
> ​
>
> root
>  |-- start_time: long (nullable = true)
>  |-- end_time: long (nullable = true)
>  |-- id: long (nullable = true)
>
> +-----------+-----------+---+
> |start_time |end_time   |id |
> +-----------+-----------+---+
> |1456050620 |1456050621 |1  |
> |1456050622 |14560506203|2  |
> |14560506204|14560506205|3  |
> +-----------+-----------+---+
>
> root
>  |-- start_time: timestamp (nullable = true)
>  |-- end_time: timestamp (nullable = true)
>  |-- id: long (nullable = true)
>
> +---------------------+---------------------+---+
> |start_time           |end_time             |id |
> +---------------------+---------------------+---+
> |2016-02-21 02:30:20.0|2016-02-21 02:30:21.0|1  |
> |2016-02-21 02:30:22.0|2431-05-28 02:03:23.0|2  |
> |2431-05-28 02:03:24.0|2431-05-28 02:03:25.0|3  |
> +---------------------+---------------------+---+
>
>
> In [21]:
>
> # working with millisecond times
>
> data = [
>
>   ("1456050620000", "1456050620000", 1)]
>
>   df = sqlContext.createDataFrame(data, ["start_time", "end_time", "id"])
>
> ​
>
> # convert epoch time strings in to spark timestamps
>
> df = df.select(
>
>   df.start_time.cast("long").alias("start_time"),
>
>   df.end_time.cast("long").alias("end_time"),
>
>   df.id)
>
> df.printSchema()
>
> df.show(truncate=False)
>
> ​
>
> # convert longs to timestamps
>
> df = df.select(
>
>   df.start_time.cast("timestamp").alias("start_time"),
>
>   df.end_time.cast("timestamp").alias("end_time"),
>
>   df.id)
>
> df.printSchema()
>
> df.show(truncate=False)
>
> root
>  |-- start_time: long (nullable = true)
>  |-- end_time: long (nullable = true)
>  |-- id: long (nullable = true)
>
> +-------------+-------------+---+
> |start_time   |end_time     |id |
> +-------------+-------------+---+
> |1456050620000|1456050620000|1  |
> +-------------+-------------+---+
>
> root
>  |-- start_time: timestamp (nullable = true)
>  |-- end_time: timestamp (nullable = true)
>  |-- id: long (nullable = true)
>
> +----------------------+----------------------+---+
> |start_time            |end_time              |id |
> +----------------------+----------------------+---+
> |48110-05-29 10:33:20.0|48110-05-29 10:33:20.0|1  |
> +----------------------+----------------------+---+
>
>
>

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