另外,通过 Spark SQL 的外部数据源 API ,DataFrame 能够被扩展,以支持第三方的数据格式或数据源。 csv: 主要是com.databricks_spark-csv_2.11-1.1.0这个库,用于支持 CSV 格式文件的读取和操作。 step 1: 在终端中输入命令:wget http://labfile.oss.aliyuncs.com/courses/610/spark_csv.tar.gz下载相关的 jar...
In this short article I will show how to create dataframe/dataset in spark sql. In scala we can use the tuple objects to simulate the row structure if the number of column is less than or equal to 22 . Lets say in our example we want to create a dataframe/dataset of 4 rows , so...
(一)创建DataFrame // 读取文件的几种方法 val df: DataFrame = spark.read.json("in/user.json") df.show() spark.read.format("json").option("header","true").load("in/user.json").show() spark.read.format("json").option("header","false").load("in/user.json").show() ### 运行结...
empDataFrame: org.apache.spark.sql.DataFrame = [name: string, age: int] In the above code we have appliedtoDF()on a sequence ofTuple2and passed two strings “name” and “age” to each tuple. These two strings will get map to columns ofempDataFrame. Let’s print the schema of the ...
at org.apache.spark.sql.DataFrame$.apply(DataFrame.scala:52) at org.apache.spark.sql.SQLContext.sql(SQLContext.scala:817) at ru.sberbank.bigdata.cloud.rb.internal.sources.history.SaveTableChanges.createResultTable(SaveTableChanges.java:104) at ru.sberbank.bigdata.cloud.rb.internal.so...
data = [("Java", "20000"), ("Python", "100000"), ("Scala", "3000")] 1. Create DataFrame from RDD One easy way to manually create PySpark DataFrame is from an existing RDD. first, let’screate a Spark RDDfrom a collection List by callingparallelize()function fromSparkContext. We ...
StringType, nullable = false) )) val data = ListBuffer[Row]() data += Row("Alyssa", "blue", "1") data += Row("Ben", "red", "2") val usersDF = spark.createDataFrame(spark.sparkContext.parallelize(data), schema) // "favorite_color" is not last column usersDF.write.partitionBy...
PythonPythonSQLScala Use dark colors for code blocksCopy fromgeoanalytics.sqlimportfunctionsasSTdata = [(4.3,"meters"),(5.6,"meters"),(2.7,"feet")]spark.createDataFrame(data, ["value","units"]) \.select(ST.create_distance("value","units").alias("create_distance")) \.show(truncate=False...
Apache SparkSQL SparkSession SparkSession 在spark2.0版本之前,SQLContext是创建DataFrame和执行SQL的入口 HiveContext通过hive sql语句操作hive表数据,兼容hive操作,hiveContext继承自SQLContext。 在spark2.0之后,SparkSession 封装了SqlContext及HiveContext所有功能。 通过SparkSession还可智能...
int nRGBValue = 15391129; // 方式一 int blueMask = 0xFF0000, greenMask = 0xFF00, redMask...