迭代遍历spark dataframe并为每行连接两列

import org.apache.spark.sql.{Row, SparkSession}
import org.apache.spark.sql.functions._

val spark = SparkSession.builder()
  .appName("DataFrame Iteration")
  .master("local")
  .getOrCreate()

val data = Seq(("John", "Doe"), ("Jane", "Smith"), ("Bob", "Johnson"))
val df = spark.createDataFrame(data).toDF("first_name", "last_name")

def concatenateColumns(row: Row): String = {
  val firstName = row.getAs[String]("first_name")
  val lastName = row.getAs[String]("last_name")
  firstName + " " + lastName
}

df.foreach(row => {
  val result = concatenateColumns(row)
  println(result)
})