scala - Spark : How to union all dataframe in loop

Question

Is there a way to get the dataframe that union dataframe in loop?

This is a sample code:

var fruits = List(
  "apple"
  ,"orange"
  ,"melon"
) 

for (x <- fruits){         
  var df = Seq(("aaa","bbb",x)).toDF("aCol","bCol","name")
}

I would want to obtain some like this:

aCol | bCol | fruitsName
aaa,bbb,apple
aaa,bbb,orange
aaa,bbb,melon

Thanks again

Answer 1

You could created a sequence of DataFrames and then use reduce:

val results = fruits.
  map(fruit => Seq(("aaa", "bbb", fruit)).toDF("aCol","bCol","name")).
  reduce(_.union(_))

results.show()