[jira] [Commented] (SPARK-29238) Add newColumn using withColumn to an empty Dataframe

["Hyukjin Kwon (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/SPARK-29238?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16939379#comment-16939379 ] 

Hyukjin Kwon commented on SPARK-29238:
--------------------------------------

Since there's no record, there would be anything will be added as a value. There's 0 records so no record that holds the literal.

> Add newColumn using withColumn to an empty Dataframe
> ----------------------------------------------------
>
>                 Key: SPARK-29238
>                 URL: https://issues.apache.org/jira/browse/SPARK-29238
>             Project: Spark
>          Issue Type: Question
>          Components: SQL
>    Affects Versions: 2.3.2
>            Reporter: ARUN KINDRA
>            Priority: Major
>
> Hi
> I'm trying to add a newColumn to an empty DF but I don't see the new column is getting added.
> Dataset<Row> newDF = sparkSession.emptyDataFrame();
>  Dataset<Row> newDf_DateConverted = newDF.withColumn("year", lit("2019"));
>  newDf_DateConverted.show();
> *Output:*
> +-------------------+
> |year|
> +-------------------+
>  +-------------------+
>  
> Basically, I am reading a HBase table and if there is no data into the table i get empty JavaPairRDD. I convert that JavaPairRDD to JavaRDD<Row> and then using schema I convert into a DF. Later I need to insert that DF values into the Hive external partitioned table. But when there is no data in HBase i am not seeing the partition getting created in HDFS.
> So, I tried the above 2 lines to code where I have empty DF and I try to add partitioned column into it, that also doesn't work.



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