如何在spark scala中将一个数据帧中的单个值复制到另一个数据帧中

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

val spark = SparkSession.builder()
  .appName("Copy Value between DataFrames")
  .getOrCreate()

val df1 = spark.createDataFrame(Seq(("value1", 1), ("value2", 2)))
  .toDF("value", "id")

val df2 = spark.createDataFrame(Seq(("initial", 1), ("initial", 2)))
  .toDF("value", "id")

val copiedValueDF = df2.withColumn("value", lit(df1.select("value").first().getString(0)))

copiedValueDF.show()

+------+---+
| value| id|
+------+---+
|value1|  1|
|value1|  2|
+------+---+