Question

我尝试在toTF TempTable中保存一些分析，但是收到以下错误＆＃34;：215：错误：值toDF不是Double＆＃34;的成员。我正在阅读Cassandra表的数据，并且我正在做一些计算。我想将这些结果保存在临时表中。我是斯卡拉的新人，有人可以帮助我吗？我的代码

case class Consumo(consumo:Double, consumo_mensal: Double, mes:   org.joda.time.DateTime,ano: org.joda.time.DateTime, soma_pf: Double,empo_gasto: Double);

object Analysegridata{

val conf = new SparkConf(true)

 .set("spark.cassandra.connection.host","127.0.0.1").setAppName("LiniarRegression")
.set("spark.cassandra.connection.port", "9042")
.set("spark.driver.allowMultipleContexts", "true")
.set("spark.streaming.receiver.writeAheadLog.enable", "true");
val sc = new SparkContext(conf);

val ssc = new StreamingContext(sc, Seconds(1))

val sqlContext = new org.apache.spark.sql.SQLContext(sc);
val checkpointDirectory = "/var/lib/cassandra/data"
ssc.checkpoint(checkpointDirectory)   // set checkpoint directory

// val context = StreamingContext.getOrCreate(checkpointDirectory)    
 import sqlContext.implicits._
 JavaSparkContext.fromSparkContext(sc);

 def rddconsumo(rddData: Double): Double = {

 val  rddData: Double = {  
  implicit val data = conf
  val grid = sc.cassandraTable("smartgrids", "analyzer").as((r:Double) => (r)).collect

 def goto(cs: Array[Double]): Double = {

   var consumo = 0.0;
   var totaldias = 0;
   var soma_pf = 0.0;
   var somamc = 0.0;
   var tempo_gasto = 0.0;
   var consumo_mensal = 0.0;
   var i=0
for (i <- 0 until grid.length) {      
   val minutos = sc.cassandraTable("smartgrids","analyzer_temp").select("timecol", "MINUTE");
   val horas = sc.cassandraTable("smartgrids","analyzer_temp").select("timecol","HOUR_OF_DAY");
   val dia = sc.cassandraTable("smartgrids","analyzer_temp").select("timecol", "DAY_OF_MONTH");
   val ano = sc.cassandraTable("smartgrids","analyzer_temp").select("timecol", "YEAR");
   val mes = sc.cassandraTable("smartgrids","analyzer_temp").select("timecol", "MONTH");
   val potencia = sc.cassandraTable("smartgrids","analyzer_temp").select("n_pf1", "n_pf2", "n_pf3")

 def convert_minutos (minuto : Int) : Double ={
  minuto/60
 }
   dia.foreach (i =>  {

   def adSum(potencia: Array[Double]) = { 

    var i=0;
      while (i < potencia.length) {
       soma_pf  += potencia(i);
       i += 1;
       soma_pf;
       println("Potemcia =" + soma_pf)  
    }  
 }
   def tempo(minutos: Array[Int]) = { 
       var i=0;
       while (i < minutos.length) {
         somamc  += convert_minutos(minutos(i))  
         i += 1;
        somamc 
     } 
  }

  def tempogasto(horas: Array[Int]) = { 
      var i=0;
      while (i < horas.length) {
       tempo_gasto = horas(i) + somamc;
       i += 1;
       tempo_gasto;
       println("Temo que o aparelho esteve ligado =" + tempo_gasto)
     } 
 }

 def consumof(dia: Array[Int]) = { 
     var i=0;
     while (i < dia.length) {
       consumo = soma_pf * tempo_gasto;
       i += 1;
       consumo; 
       println("Consumo diario =" + consumo)       
     } 
  }
})

mes.foreach (i => {

 def totaltempo(dia: Array[Int]) = { 
     var i = 0;
     while(i < dia.length){
       totaldias += dia(i);
       i += 1;
       totaldias;
       println("Numero total de dias =" + totaldias)  
     }
 }
 def consumomensal(mes: Array[Int]) = { 
     var i = 0;
     while(i < mes.length){
      consumo_mensal = consumo * totaldias;
      i += 1;
     consumo_mensal;
     println("Consumo Mensal =" + consumo_mensal);
   }
} 
})

}
    consumo; 
    totaldias;
    consumo_mensal; 
    soma_pf;
    tempo_gasto;
    somamc

}

 rddData

  }
   rddData.toDF().registerTempTable("rddData")
 }
      ssc.start()
      ssc.awaitTermination()




 error: value toDF is not a member of Double"

Answer 1

相当不清楚你正在尝试做什么（代码太多，尝试提供 minimal 示例），但有一些明显的问题：

rddData类型为Double ：好像应该是RDD[Double]（这是Double值的分布式集合）。尝试将单个Double值保存为表并没有多大意义，确实 - 不起作用（toDF可以在RDD上调用，而不是任何类型，特别是不在Double上，如编译器警告的那样。
您collect()数据：如果您要加载RDD，使用某些操作对其进行转换，然后将其另存为表格 - collect()应该不是呼吁RDD。 collect()将所有数据（分布在群集中）发送到单个＆＃34;驱动程序＆＃34;机器（运行此代码的机器） - 之后您没有利用群集，并且再次不使用RDD数据结构，因此您无法使用{将数据转换为DataFrame {1}}。

Scala：将结果保存在toDf临时表中

1 个答案: