spark计算两个DataFrame的差集、交集、合集

2019年10月26日 203次阅读 来源: spark

spark 计算两个dataframe 的差集、交集、合集，只选择某一列来对比比较好。新建两个 dataframe ：

import org.apache.spark.{SparkConf, SparkContext}
import org.apache.spark.sql.SQLContext

def main(args: Array[String]): Unit = {

    val conf = new SparkConf().setAppName("TTyb").setMaster("local")
    val sc = new SparkContext(conf)
    val spark = new SQLContext(sc)
    val sentenceDataFrame = spark.createDataFrame(Seq(
      (1, "asf"),
      (2, "2143"),
      (3, "rfds")
    )).toDF("label", "sentence")
    sentenceDataFrame.show()

    val sentenceDataFrame1 = spark.createDataFrame(Seq(
      (1, "asf"),
      (2, "2143"),
      (4, "f8934y")
    )).toDF("label", "sentence")
    sentenceDataFrame1.show()
}

差集 except

val newDF = sentenceDataFrame1.select("sentence").except(sentenceDataFrame.select("sentence"))
newDF.show()

+——–+
|sentence|
+——–+
|f8934y |
+——–+

交集 intersect

val newDF = sentenceDataFrame1.select("sentence").intersect(sentenceDataFrame.select("sentence"))
newDF.show()

+——–+
|sentence|
+——–+
| asf|
| 2143|
+——–+

合集 union

val newDF = sentenceDataFrame1.select("sentence").union(sentenceDataFrame.select("sentence"))
newDF.show()

+——–+
|sentence|
+——–+
| asf|
| 2143|
| f8934y|
| asf|
| 2143|
| rfds|
+——–+

合集最好去一下重 distinct ：

val newDF = sentenceDataFrame1.select("sentence").union(sentenceDataFrame.select("sentence")).distinct()
newDF.show()

+——–+
|sentence|
+——–+
| rfds|
| asf|
| 2143|
| f8934y|
+——–+

    原文作者：spark
    原文地址: https://www.cnblogs.com/TTyb/p/7991952.html
    本文转自网络文章，转载此文章仅为分享知识，如有侵权，请联系博主进行删除。
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