block3.scala

class DataFrameJoinSuite extends QueryTest with SharedSparkSession {  
  import testImplicits._  
  
  test("join - join using") {  
    val df = Seq(1, 2, 3).map(i => (i, i.toString)).toDF("int", "str")  
    val df2 = Seq(1, 2, 3).map(i => (i, (i + 1).toString)).toDF("int", "str")  
  
    checkAnswer(  
      df.join(df2, "int"),  
      Row(1, "1", "2") :: Row(2, "2", "3") :: Row(3, "3", "4") :: Nil)  
  }
}