Multiple constructors with the same number of parameters exception while transforming data in spark using scala

Question

Below is the code

    def findUniqueGroupInMetadata(sc: SparkContext): Unit = {
    val merchantGroup = sc.cassandraTable("local_pb",     "merchant_metadata").select("group_name")

try {
  val filterByWithGroup = merchantGroup.filter {
    row =>
      row.getStringOption("group_name") match {
        case Some(s: String) if (s != null) => true
        case None => false
      }
  }.map(row => row.getStringOption("group_name").get.capitalize)


  //filterByWithGroup.take(15).foreach(data => println("merchantGroup => " + data))
  filterByWithGroup.saveToCassandra("local_pb", "merchant_group", SomeColumns("group_name"))
} catch {
  case e: Exception => println(e.printStackTrace())

}

}

Exception =>

java.lang.IllegalArgumentException: Multiple constructors with the same number of parameters not allowed.
    at com.datastax.spark.connector.util.Reflect$.methodSymbol(Reflect.scala:16)
    at com.datastax.spark.connector.util.ReflectionUtil$.constructorParams(ReflectionUtil.scala:63)
    at com.datastax.spark.connector.mapper.DefaultColumnMapper.<init>(DefaultColumnMapper.scala:45)
    at com.datastax.spark.connector.mapper.LowPriorityColumnMapper$class.defaultColumnMapper(ColumnMapper.scala:47)
    at com.datastax.spark.connector.mapper.ColumnMapper$.defaultColumnMapper(ColumnMapper.scala:51)

Answer 1

I found the answer after looking into some blogs.

When I converted the RDD[String] to RDD[Tuple1[String]] everything went smooth. So basically in order to save data to Cassandra, data needs to be of type RDD[TupleX[String]] here x can be 1,2,3... or data can be RDD[SomeCaseClass]