DSL风格语法(次要)_大数据培训

DSL风格语法(次要)

1）创建一个DataFrame

scala> val df = spark.read.json(“/opt/module/spark/examples/src/main/resources/people.json”)

df: org.apache.spark.sql.DataFrame = [age: bigint, name: string]

2）查看DataFrame的Schema信息

scala> df.printSchema

root

 |– age: long (nullable = true)

 |– name: string (nullable = true)

3）只查看”name”列数据

4）查看”name”列数据以及”age+1”数据

5）查看”age”大于”21”的数据

6）按照”age”分组，查看数据条数