你应该匹配一个完整的结构:

You should match a full structure:

val result = df1.selectExpr(
  "CAST(id AS integer) id",
  "s1",
  "CAST(d AS decimal) d",
  "CAST(s2 AS array<struct<u:integer,v:integer>>) s2"
)

它应该为您提供以下架构:

which should give you following schema:

result.printSchema

root
 |-- id: integer (nullable = true)
 |-- s1: struct (nullable = true)
 |    |-- x: string (nullable = true)
 |    |-- y: string (nullable = true)
 |-- d: decimal(10,0) (nullable = true)
 |-- s2: array (nullable = true)
 |    |-- element: struct (containsNull = true)
 |    |    |-- u: integer (nullable = true)
 |    |    |-- v: integer (nullable = true)

和数据:

result.show

+---+-----+---+----------------+
| id|   s1|  d|              s2|
+---+-----+---+----------------+
|  1|[a,b]|  8|[[1,2], [12,22]]|
|  2|[c,d]|  9|[[3,4], [33,44]]|
+---+-----+---+----------------+