如何在数组类型列的值中添加索引

Question

我需要在列（数组）中添加序号我的源数据是镶木地板格式，数量接近 20 亿条记录。我只需要从镶木地板中选择键和代码列并将序列号添加到 ref_codes 并将其加载回 S3

Key_1       Key_2       Key_3  Ref_codes
112240386   7435038894  2    [4659,53540,78907]
113325994   7940375640  1      [7232,7840,83969]
223352476   7765270324  4      [9999]
345936074   7950076012  1      [78650,4829,30000]
            
            
Key_1       Key_2       Key_3   Ref_codes
112240386   7435038894  2       [(4659,0),(53540,1),(78907,2)]
113325994   7940375640  1       [(7232,0),(7840,1),(83969,2)]
223352476   7765270324  4       [(9999,0)]
345936074   7950076012  1       [(78650,0),(4829,1),(30000,2)]

我是 Scala 的新手，我尝试了多种选择但没有得到合适的 results.Any 帮助非常感谢...

Answer 1

您可以在最新版本的 spark 中使用 transform 等高阶函数，如下所示。数据：

val df = Seq(
  ("112240386", "7435038894", 2, Array(4659, 53540, 7890)),
  ("113325994", "7940375640", 1, Array(7232, 7840, 8396)),
  ("223352476", "7765270324", 4, Array(999)),
  ("345936074", "7950076012", 1, Array(78650, 4829, 3000)),
).toDF("key_1", "key_2", "key_3", "ref_code")

Spark 3.0.0+

df.withColumn("ref_code", transform($"ref_code", (x, i) => struct(x, i) ))

Spark > 2.4

df.withColumn("ref_code", expr("transform(ref_code, (x,i) -> (x,i) )"))

Spark < 2.4

val addIndex = udf((arr: Seq[Int]) => arr.zipWithIndex)
df.withColumn("ref_code", addIndex($"ref_code")).show(false)

输出：

+---------+----------+-----+----------------------------------+
|key_1    |key_2     |key_3|ref_code                          |
+---------+----------+-----+----------------------------------+
|112240386|7435038894|2    |[[4659, 0], [53540, 1], [7890, 2]]|
|113325994|7940375640|1    |[[7232, 0], [7840, 1], [8396, 2]] |
|223352476|7765270324|4    |[[999, 0]]                        |
|345936074|7950076012|1    |[[78650, 0], [4829, 1], [3000, 2]]|
+---------+----------+-----+----------------------------------+

关于转换的更多示例是 here

如何在数组类型列的值中添加索引

How to add index in values with array type column

scala

apache-spark

parquet