spark sql add comment with withComment, it is not work - apache-spark

Question

I want to add remarks to the dataframe, then write hive table,but it is not work.That is to say, the remarks of the table are not added.
I try in spark 2.4 and spark 3, it is not work. But the lower version seems to work, I don't know why,I tried to read the source code but found nothing, if you know why, please tell me, thank you
The code as follows
val personRDD: RDD[Row] = GetTestRDD.map((line: String) => {
val arr: Array[String] = line.split(" ")
Row(arr(0).toInt, arr(1), arr(2).toInt)
})
val schema: StructType = StructType(List(
StructField("id", IntegerType, nullable = false),
StructField("name", StringType, nullable = false),
StructField("age", IntegerType, nullable = false)
))
val frame: DataFrame = sparkSession.createDataFrame(personRDD, schema)
println("输出原始信息")
frame.schema.foreach((s: StructField) => println(s.name, s.metadata))
//添加备注后处理
val commentMap: Map[String, String] = Map("id" -> "唯一标识", "name" -> "姓名", "age" -> "年龄")
val newSchema: Seq[StructField] = frame.schema.map((s: StructField) => {
println(commentMap(s.name))
s.withComment(commentMap(s.name))
})
sparkSession.createDataFrame(frame.rdd, StructType(newSchema)).repartition(10)
println("输出处理后的信息")
frame.schema.foreach((s: StructField) => println(s.name, s.metadata))
the output
输出原始信息
(id,{})
(name,{})
(age,{})
输出处理后的信息
(id,{})
(name,{})
(age,{})