如何在 Spark Java 中使用数据框构建基于其他列的列？

Question

I need to make a column based on other columns. I have this dataframe DF1:

---------------------
  a   | b    | c    |
------|------|------|
value1|value2|value3|
------|------|------|

The expected result is that I add a column d with the values of the columns a, b and c separated with "|":

------------------------------------------
  a   | b    | c    | d
------|------|------|---------------------
value1|value2|value3|value1|value2|value3
------|------|------|---------------------

How can I do this in Spark Java using dataframe?

Answer 1

Use expr("concat('|',*)") , Check below code.

import org.apache.spark.sql.functions.expr

df.withColumn("d",expr("concat_ws('|',*)")).show(false)
+------+------+------+--------------------+
|a     |b     |c     |d                   |
+------+------+------+--------------------+
|value1|value2|value3|value1|value2|value3|
+------+------+------+--------------------+