apache-spark - Spark 将由元组组成的列添加到数据框

Question

我正在使用 Spark 1.6，我想向数据框添加一列。新列实际上是一个常量序列:Seq("-0", "-1", "-2", "-3")

这是我的原始数据框:

scala> df.printSchema()

root
|-- user_name: string (nullable = true)
|-- test_name: string (nullable = true)

df.show()

|user_name| test_name|

+------------+--------------------+

|user1| SAT|

| user9| GRE|

| user7|MCAT|

我想添加这个额外的列(尝试)，这样新的数据框就变成了:

|user_name|test_name|attempt|
+------------+--------------------+
|user1| SAT|Seq("-0","-1","-2","-3")|
| user9| GRE|Seq("-0","-1","-2","-3")
| user7|MCAT|Seq("-0","-1","-2","-3")

我该怎么做？

Answer 1

您可以使用 withColumn 函数:

 import org.apache.spark.sql.functions._
 df.withColumn("attempt", lit(Array("-0","-1","-2","-3")))