kopunk的专栏

1.有header的txt文件创建DataFrame：利用 mapPartitionsWithIndexval teacherRdd = sc.textFile("src/test/teacher.txt")val teacherRddSchema = teacherRdd.mapPartitionsWithIndex((idx, iter) => if (idx == 0) i...

先创建一个rank spec// 用df("salary").asc代表升序排列，desc代表降序val rankSpec = Window.partitionBy("age").orderBy(df("salary").desc)然后为自己的表添加一列rankval sararyRank = df.withColumn("rank",dense_rank().over(ra...