如何爆炸一个结构数组

Question

我有一个这样的模式

root
 |-- CaseNumber: string (nullable = true)
 |-- Interactions: struct (nullable = true)
 |    |-- EmailInteractions: array (nullable = true)
 |    |    |-- element: string (containsNull = true)
 |    |-- PhoneInteractions: array (nullable = true)
 |    |    |-- element: struct (containsNull = true)
 |    |    |    |-- Contact: struct (nullable = true)
 |    |    |    |    |-- id: string (nullable = true)
 |    |    |    |-- CreatedOn: string (nullable = true)
 |    |    |    |-- Direction: string (nullable = true)
 |    |-- WebInteractions: array (nullable = true)
 |    |    |-- element: string (containsNull = true)

我想爆炸三个数组（EmailInteractions，PhoneInteractions，WebInteractions），并与CaseNumber分组并创建三个表并执行此sql查询

Select casenumber,CreatedOn
from EmailInteration
where Direction = 'Outgoing'

union all

Select casenumber,CreatedOn
from PhoneInteraction
where Direction = 'Outgoing'

union all

Select casenumber,CreatedOn
from WebInteraction
where Direction = 'Outgoing'

用于检索架构的代码

val dl = spark.read.format("com.databricks.spark.avro").load("adl://power.azuredatalakestore.net/Se/eventhubspace/eventhub/0_2020_01_20_*_*_*.avro")
val dl1=dl.select($"body".cast("string")).map(_.toString())
val dl2=spark.read.json(dl1)
val dl3=dl2.select($"Content.*",$"RawProperties.UserProperties.*")

我是databrick的新手，任何帮助将不胜感激。预先感谢。