Spark-SQL在IDEA中创建SparkSQL程序|DF风格编程|RDD转换为DF

POM

<dependencies>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-core_2.11</artifactId>
            <version>2.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-sql_2.11</artifactId>
            <version>2.1.1</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>SparkCoreTest</finalName>
        <plugins>
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.3.2</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>testCompile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

DF风格编程代码实现

// 1. 创建SparkSession对象
    val spark: SparkSession = SparkSession.builder()
      .master("local[*]")
      .appName("SparkSQL")
      .getOrCreate()

    val context: SparkContext = spark.sparkContext

    // 2. 导入隐式转换 : spark为创建得SparkSession对象
    import spark.implicits._

    // 3. 读取数据创建DF
    val df: DataFrame = spark.read.json("D:\\MyWork\\WorkSpaceIDEA\\scalaDemo\\sparksql\\src\\main\\resources\\people.json")

    // 4. SQL风格编程
    df.createTempView("people")
    spark.sql("select * from people").show()

    // 5. DSL风格编程
    df.select("name").show()

    // 6. 关闭连接
    spark.stop()

RDD转换为DF代码实现