Scala Spark DataFrame : dataFrame.select multiple columns given a Sequence of column names

Question

val columnName=Seq(\"col1\",\"col2\",.....\"coln\");

Is there a way to do dataframe.select operation to get dataframe containing only the column na

Answer 1

Since dataFrame.select() expects a sequence of columns and we have a sequence of strings, we need to convert our sequence to a List of cols and convert that list to the sequence. columnName.map(name => col(name)): _* gives a sequence of columns from a sequence of strings, and this can be passed as a parameter to select():

  val columnName = Seq("col1", "col2")
  val DFFiltered = DF.select(columnName.map(name => col(name)): _*)

Answer 2

val columnNames = Seq("col1","col2",....."coln")

// using the string column names:
val result = dataframe.select(columnNames.head, columnNames.tail: _*)

// or, equivalently, using Column objects:
val result = dataframe.select(columnNames.map(c => col(c)): _*)