When I tried to display the date column from pyspark dataframe through show() and display(dataframe) ,those format of the data columns are different . Now how do we arrive which date format is being there in dataframe ?
Display : 2018-02-15T06:47:19.000+0000
show : 2018-02-15 06:47:19
Timestamp in dataframe isn't stored as a string - it's stored using internal representation (Long in case of timestamp) that is then converted into text by show or display.
Related
I have a csv file in which a date column has values like 01080600, basically MM-dd-HH-mm.
I want to add a column in dataframe which shows this in a more readable format.
I do :
spark.sql("SELECT date...")
.withColumn("readable date", to_date(col("date"), "MM:dd HH:mm"))
.show(10)
But readable date is returned null.
What am I missing here?
While formating or converting to date or timestamp you need to provide the date_format as is following your pattern , example in your case you need to modify your format as below and further which can be formatted depending on the final format you wish your date col to take using date_format
References to various patterns and parsing can be found here
To Timestamp
sql.sql("""
SELECT
TO_TIMESTAMP('01080600','ddMMhhmm') as date,
DATE_FORMAT(TO_TIMESTAMP('01080600','ddMMhhmm'),'MM/dd hh:mm') as formated_date
""").show()
+-------------------+-------------+
| date|formated_date|
+-------------------+-------------+
|1970-08-01 06:00:00| 08/01 06:00|
+-------------------+-------------+
I am new to Azure Databricks,I am trying to write a dataframe output to a delta table which consists TIMESTAMP column. But strangely it changes the TIMESTAMP pattern after writing to delta table.
My DataFrame Output column holds the value in this format 2022-05-13 17:52:09.771,
But After writing it to the Table, The column value is getting populated as
2022-05-13T17:52:09.771+0000
I am using below function to generate this Dataframe output
val pretsUTCText = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'")
val tsUTCText: String = pretsUTCTextNew.format(ts)
val tsUTCCol : Column = lit(tsUTCText)
val df = df2.withColumn(to_timestamp(timestampConverter.tsUTCCol,"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"))
The Dataframe output is returning 2022-05-13 17:52:09.771 as TIMESTAMP pattern.
But After writing it to Delta Table I see the same value is getting populated as 2022-05-13T17:52:09.771+0000
Thanks in Advance. I could not find any solution.
I have just found the same behaviour on Databricks as you, and it behaves differently than the Databricks document. It seems after some versions Databricks show timezone as a default so you see additional +0000. I think you can use date_format function when you populate data if you don't want it. Also, I think you don't need 'Z' in format text as it is for timezone. See the screenshot below.
The development is in Azure Data Factory -- Data Flow
I am getting an input file with various columns and one column with DateFormat ('MM/dd/yyyy'T'HH:mm:ss').
I am trying to convert the above DateFormat to toTimestamp('yyyy-MM-dd HH:mm:ss.SSS')
I have tried with the below format in Derived Column tab on the particular column needed in sink below is the Expression used to convert such case.
iifNull(toTimestamp(<string_column_name>,'MM/dd/yyyy\'T\'HH:mm:ss'), toTimestamp(<string_column_name>,'yyyy-MM-dd HH:mm:ss.SSS'))
For reference i am attaching the sample Date format got in the input file 01/26/2018 00:00:00.
Ref 4, should be converted to the format as 2018-01-26 00:00:00.
The format of date 01/26/2018 00:00:00 you provided is 'MM/dd/yyyy HH:mm:ss' which isn't contained in your expression. This leads to you got Null. If your column also has 'MM/dd/yyyy'T'HH:mm:ss' and 'yyyy-MM-dd HH:mm:ss.SSS' format, you can try this expression:
iifNull(toTimestamp(<string_column_name>,'MM/dd/yyyy\'T\'HH:mm:ss'), toTimestamp(<string_column_name>,'yyyy-MM-dd HH:mm:ss.SSS'),toTimestamp(<string_column_name>,'MM/dd/yyyy HH:mm:ss'))
Data preview:
Could you please guide with below query.
I need to convert below string column to date.
Input and expected output is provided in screenshot.
Input table: column maturity_date is in string datatype.
I tried below but not working as expected
to_date(from_unixtime(unix_timestamp(maturity_date,'MM/DD/YYYY H:mm:ss'),'yyyy-mm-dd')
Try using lower case letters. Upper case means another thing (day of year (D) and week-year (Y)).
to_date(from_unixtime(unix_timestamp(maturity_date,'MM/dd/yyyy H:mm:ss'),'yyyy-MM-dd')
Correct input format is 'MM/dd/yyyy H:mm:ss', not 'MM/DD/YYYY H:mm:ss'
Correct output format is yyyy-MM-dd, not yyyy-mm-dd. mm is minutes. MM is month
Read more about date format used in Hive here SimpleDateFormat
I have table which stores datetime as varchar
Format looks like this 2018-07-16 15:00:00.0 ,
I want to parse this to extract only date part so that I use date part to compare with date in string format such as '2018-07-20' in where clause. What is the best way to achieve this in presto?
This particular format (based on example value 2018-07-16 15:00:00.0 in the question) is understood by cast from varchar to timestamp. You then need to extract date part with another cast:
presto> SELECT CAST(CAST('2018-07-16 15:00:00.0' AS timestamp) AS date);
_col0
------------
2018-07-16
(1 row)