Spark Dataframe :How to add a index Column : Aka Distributed Data Index

Question

I read data from a csv file ,but don\'t have index.

I want to add a column from 1 to row\'s number.

What should I do,Thanks (scala)

Answer 1

NOTE : Above approaches doesn't give a sequence number, but it does give increasing id.

Simple way to do that and ensure the order of indexes is like below.. zipWithIndex.

Sample data.

+-------------------+
|               Name|
+-------------------+
|     Ram Ghadiyaram|
|        Ravichandra|
|              ilker|
|               nick|
|             Naveed|
|      Gobinathan SP|
|Sreenivas Venigalla|
|     Jackela Kowski|
|   Arindam Sengupta|
|            Liangpi|
|             Omar14|
|        anshu kumar|
+-------------------+

---

    package com.example

import org.apache.spark.internal.Logging
import org.apache.spark.sql.SparkSession._
import org.apache.spark.sql.functions._
import org.apache.spark.sql.types.{LongType, StructField, StructType}
import org.apache.spark.sql.{DataFrame, Row}

/**
  * DistributedDataIndex : Program to index an RDD  with
  */
object DistributedDataIndex extends App with Logging {

  val spark = builder
    .master("local[*]")
    .appName(this.getClass.getName)
    .getOrCreate()

  import spark.implicits._

  val df = spark.sparkContext.parallelize(
    Seq("Ram Ghadiyaram", "Ravichandra", "ilker", "nick"
      , "Naveed", "Gobinathan SP", "Sreenivas Venigalla", "Jackela Kowski", "Arindam Sengupta", "Liangpi", "Omar14", "anshu kumar"
    )).toDF("Name")
  df.show
  logInfo("addColumnIndex here")
  // Add index now...
  val df1WithIndex = addColumnIndex(df)
    .withColumn("monotonically_increasing_id", monotonically_increasing_id)
  df1WithIndex.show(false)

  /**
    * Add Column Index to dataframe to each row
    */
  def addColumnIndex(df: DataFrame) = {
    spark.sqlContext.createDataFrame(
      df.rdd.zipWithIndex.map {
        case (row, index) => Row.fromSeq(row.toSeq :+ index)
      },
      // Create schema for index column
      StructType(df.schema.fields :+ StructField("index", LongType, false)))
  }
}

Result :

+-------------------+-----+---------------------------+
|Name               |index|monotonically_increasing_id|
+-------------------+-----+---------------------------+
|Ram Ghadiyaram     |0    |0                          |
|Ravichandra        |1    |8589934592                 |
|ilker              |2    |8589934593                 |
|nick               |3    |17179869184                |
|Naveed             |4    |25769803776                |
|Gobinathan SP      |5    |25769803777                |
|Sreenivas Venigalla|6    |34359738368                |
|Jackela Kowski     |7    |42949672960                |
|Arindam Sengupta   |8    |42949672961                |
|Liangpi            |9    |51539607552                |
|Omar14             |10   |60129542144                |
|anshu kumar        |11   |60129542145                |
+-------------------+-----+---------------------------+