yanghongjun 发表于 2018-10-19 11:12:49

Spark SQL笔记整理(三):加载保存功能与Spark SQL函数

package cn.xpleaf.bigdata.spark.scala.sql.p2  import cn.xpleaf.bigdata.spark.scala.sql.p1._01SparkSQLOps
  import org.apache.log4j.{Level, Logger}
  import org.apache.spark.{SparkConf, SparkContext}
  import org.apache.spark.sql.hive.HiveContext
  /**
  * 通过创建HiveContext来操作Hive中表的数据
  * 数据源:
  * teacher_info.txt

  *   name(String)   >  *   zhangsan,175
  *   lisi,180
  *   wangwu,175
  *   zhaoliu,195
  *   zhouqi,165
  *   weiba,185
  *
  *   create table teacher_info(
  *   name string,

  *    >  *   ) row format delimited
  *   fields terminated by ',';
  *
  * teacher_basic.txt
  *   name(String)    age(int)    married(boolean)    children(int)
  *   zhangsan,23,false,0
  *   lisi,24,false,0
  *   wangwu,25,false,0
  *   zhaoliu,26,true,1
  *   zhouqi,27,true,2
  *   weiba,28,true,3
  *
  *   create table teacher_basic(
  *   name string,
  *   age int,
  *   married boolean,
  *   children int
  *   ) row format delimited
  *   fields terminated by ',';
  * *
  * 需求:
  *1.通过sparkSQL在hive中创建对应表,将数据加载到对应表
  *2.执行sparkSQL作业,计算teacher_info和teacher_basic的关联信息,将结果存放在一张表teacher中
  *
  * 在集群中执行hive操作的时候,需要以下配置:
  *   1、将hive-site.xml拷贝到spark/conf目录下,将mysql connector拷贝到spark/lib目录下
  2、在$SPARK_HOME/conf/spark-env.sh中添加一条记录
  export SPARK_CLASSPATH=$SPARK_CLASSPATH:$SPARK_HOME/lib/mysql-connector-java-5.1.39.jar
  */
  object _01HiveContextOps {
  def main(args: Array): Unit = {
  Logger.getLogger("org.apache.spark").setLevel(Level.OFF)
  val conf = new SparkConf()
  //            .setMaster("local")
  .setAppName(_01SparkSQLOps.getClass.getSimpleName)
  val sc = new SparkContext(conf)
  val hiveContext = new HiveContext(sc)
  //创建teacher_info表
  hiveContext.sql("CREATE TABLE teacher_info(" +
  "name string, " +
  "height double) " +
  "ROW FORMAT DELIMITED " +
  "FIELDS TERMINATED BY ','")
  hiveContext.sql("CREATE TABLE teacher_basic(" +
  "name string, " +
  "age int, " +
  " married boolean, " +
  "children int) " +
  "ROW FORMAT DELIMITED " +
  "FIELDS TERMINATED BY ','")
  // 向表中加载数据
  hiveContext.sql("LOAD DATA LOCAL INPATH '/home/uplooking/data/hive/sql/teacher_info.txt' INTO TABLE teacher_info")
  hiveContext.sql("LOAD DATA LOCAL INPATH '/home/uplooking/data/hive/sql/teacher_basic.txt' INTO TABLE teacher_basic")
  //第二步操作 计算两张表的关联数据
  val joinDF = hiveContext.sql("SELECT " +
  "b.name, " +
  "b.age, " +
  "if(b.married, '已婚', '未婚') as married, " +
  "b.children, " +
  "i.height " +
  "FROM teacher_info i " +
  "INNER JOIN teacher_basic b ON i.name = b.name")
  joinDF.collect().foreach(println)
  joinDF.write.saveAsTable("teacher")
  sc.stop()
  }
  }

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