How can I add several columns in Spark while using the same WHEN condition?

edit

You can use the selectExpr method in Spark to add multiple columns with the same WHEN condition. Here's an example:

val df = Seq((1, "A"), (2, "B"), (3, "C")).toDF("id", "letter")

val newDf = df.selectExpr("*",
  "CASE WHEN id < 2 THEN 'Low' ELSE 'High' END as id_category",
  "CASE WHEN id < 2 THEN 'Small' ELSE 'Big' END as id_size")

newDf.show()

In this example, we're adding two columns (id_category and id_size) with the same WHEN condition (id < 2). The selectExpr method allows us to pass in multiple expressions separated by commas, which are evaluated and added as new columns to the DataFrame.