常见应用 - SparkSql 之 DSL(1)

package com.zhangxiaofan.test

import org.apache.spark._
import org.apache.spark.sql.SparkSession

/**
  * @author ZhangXiaoFan
  * @create 2020-10-20 9:58
  */
case class Person2(name: String, age: Int, sex: String, salary: Int, deptNo: Int)
case class Dept(deptNo: Int, deptName: String)

object SparkSQLDSLDemo {
  def main(args: Array[String]): Unit = {
    //1、创建spark上下文环境
    val conf: SparkConf = new SparkConf()
      .setMaster("local[*]")
      .setAppName("WorldCount")
    val spark = new SparkSession.Builder()
      .config(conf)
      .getOrCreate()
    import spark.implicits._
    import org.apache.spark.sql.functions._

    // 2. 直接创建模拟数据
    val rdd1 = spark.sparkContext.parallelize(Array(
      Person2("张三", 21, "M", 1235, 1),
      Person2("李四", 20, "F", 1235, 1),
      Person2("王五", 26, "M", 1235, 1),
      Person2("小明", 25, "F", 1225, 1),
      Person2("小花", 24, "F", 1425, 1),
      Person2("小华", 23, "M", 1215, 1),
      Person2("gerry", 22, "F", 1415, 2),
      Person2("tom", 21, "F", 1855, 2),
      Person2("lili", 20, "F", 1455, 2),
      Person2("莉莉", 18, "M", 1635, 2)
    ))
    val rdd2 = spark.sparkContext.parallelize(Array(
      Dept(1, "部门1"),
      Dept(2, "部门2")
    ))

    val personDataFrame = rdd1.toDF()
    val deptDataFrame = rdd2.toDF()

    //注册udf
    var sexToNum = udf((sex: String) => {
      sex.toUpperCase match {
        case "M" => 0
        case "F" => 1
        case _ => -1
      }
    })

    //select
    println("----select-----")
    deptDataFrame.select(col("deptNo"),col("deptName")).show()
    deptDataFrame.select(col("deptNo") + 1 as "deptNo" ,col("deptName")).show()
    deptDataFrame.select((col("deptNo") + 1).alias("deptNo") ,col("deptName")).show()
    personDataFrame.select(col("name"),col("age") , col("sex"), sexToNum(col("sex")).as("sex_num")).show()

    // where/filter
    println("------where/filter-------")
    personDataFrame.where(col("age").>(22 ) ).show()
    personDataFrame.where(col("age") > 20 && col("sex") === "M" && col("deptNo") === 1).show()
    personDataFrame.where(col("age") > 20 || col("sex") === "M" || col("deptNo").equalTo(1)).show()


    // group by
    println("------group by-------")
    personDataFrame
      .groupBy(col("sex"))
      .agg(sum(col("salary")),avg(col("salary")).as("avg_salary"))
      .show()

    println("----------join--------------------")
    personDataFrame.join(deptDataFrame, (personDataFrame.col("deptNo") === deptDataFrame.col("deptNo")).and(personDataFrame.col("deptNo") === deptDataFrame.col("deptNo")) ,"inner").show()
    personDataFrame.join(deptDataFrame, "deptNo" ).show()
    personDataFrame
      .join(deptDataFrame, Seq("deptNo"), "left_outer").show

  }
}