我的Spark学习笔记(五)

导读:本篇文章讲解 我的Spark学习笔记(五),希望对大家有帮助,欢迎收藏,转发!站点地址:www.bmabk.com

启动spark-shell后,准备数据文件D:/Dump/SparkDB/people.txt

Michael, 29
Andy, 30
Justin, 19
scala> val file = sc.textFile("D:/Dump/SparkDB/people.txt")
file: org.apache.spark.rdd.RDD[String] = D:/Dump/SparkDB/people.txt MapPartitionsRDD[1] at textFile at <console>:24

scala> file.cache
res0: file.type = D:/Dump/SparkDB/people.txt MapPartitionsRDD[1] at textFile at <console>:24

scala> file.collect
res1: Array[String] = Array(Michael, 29, Andy, 30, Justin, 19)

准备数据文件D:/Dump/SparkDB/people.json

{"name":"jack","age":12}
{"name":"lili","age":22}
{"name":"cc","age":11}
{"name":"vv","age":13}
{"name":"lee","age":14}
scala> import spark.implicits._
import spark.implicits._

scala> import org.apache.spark.sql.SparkSession
import org.apache.spark.sql.SparkSession

scala> val spark = SparkSession.builder().appName("Spark SQL basic example").getOrCreate()
19/12/05 14:50:58 WARN SparkSession$Builder: Using an existing SparkSession; some configuration may not take effect.
spark: org.apache.spark.sql.SparkSession = org.apache.spark.sql.SparkSession@79cfc008

scala> val df = spark.read.json("D:/Dump/SparkDB/people.json")
df: org.apache.spark.sql.DataFrame = [age: bigint, name: string]

scala> df.createOrReplaceTempView("people")

scala> val sqlDF = spark.sql("SELECT * FROM people")
sqlDF: org.apache.spark.sql.DataFrame = [age: bigint, name: string]

scala> sqlDF.show()
+---+----+
|age|name|
+---+----+
| 12|jack|
| 22|lili|
| 11|  cc|
| 13|  vv|
| 14| lee|
+---+----+

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