通过Spark SQL关联查询两个HDFS上的文件操作

order_created.txt   订单编号  订单创建时间

10703007267488  2014-05-01 06:01:12.334+01
10101043505096  2014-05-01 07:28:12.342+01
10103043509747  2014-05-01 07:50:12.33+01
10103043501575  2014-05-01 09:27:12.33+01
10104043514061  2014-05-01 09:03:12.324+01

order_picked.txt   订单编号  订单提取时间

10703007267488  2014-05-01 07:02:12.334+01
10101043505096  2014-05-01 08:29:12.342+01
10103043509747  2014-05-01 10:55:12.33+01

上传上述两个文件到HDFS:

hadoop fs -put order_created.txt /data/order_created.txt
hadoop fs -put order_picked.txt /data/order_picked.txt

通过Spark SQL关联查询两个文件

val hiveContext = new org.apache.spark.sql.hive.HiveContext(sc)
import hiveContext._

case class OrderCreated(order_no:String,create_date:String)
case class OrderPicked(order_no:String,picked_date:String)

val order_created = sc.textFile("/data/order_created.txt").map(_.split("	")).map( d => OrderCreated(d(0),d(1)))
val order_picked = sc.textFile("/data/order_picked.txt").map(_.split("	")).map( d => OrderPicked(d(0),d(1)))

order_created.registerTempTable("t_order_created")
order_picked.registerTempTable("t_order_picked")

#手工设置Spark SQL task个数
hiveContext.setConf("spark.sql.shuffle.partitions","10")
hiveContext.sql("select a.order_no, a.create_date, b.picked_date from t_order_created a join t_order_picked b on a.order_no = b.order_no").collect.foreach(println)

执行结果如下：

[10101043505096,2014-05-01 07:28:12.342+01,2014-05-01 08:29:12.342+01]
[10703007267488,2014-05-01 06:01:12.334+01,2014-05-01 07:02:12.334+01]
[10103043509747,2014-05-01 07:50:12.33+01,2014-05-01 10:55:12.33+01]