所有Spark SQL 数据类型的基类型。 请注意,实现镜像 PySpark:spark/python/pyspark/sql/types.py Scala 版本为 spark/sql/catalyst/src/main/scala/org/apache/spark/sql/types/*。
代码示例来源:origin: jpmml/jpmml-sparkml public DataField createDataField(FieldName name){ StructType schema = getSchema(); StructField field = schema.apply(name.getValue()); org.apache.spark.sql.types.DataType sparkDataType = field.dataType(); if(sparkDataType instanceof StringType){ return...
PySpark SQL Types class is a base class of all data types in PySpark which are defined in a package pyspark.sql.types.DataType and are used to create
在Spark SQL中有两种方式可以在DataFrame和RDD进行转换,第一种方法是利用反射机制,推导包含某种类型的RDD,通过反射将其转换为指定类型的DataFrame,适用于提前知道RDD的schema。 第二种方法通过编程接口与RDD进行交互获取schema,并动态创建DataFrame,在运行时决定列及其类型。
scala> import org.apache.spark.sql.types._ import org.apache.spark.sql.types._ scala> val fields = schemaString.split(" ").map(fieldName => StructField(fieldName, StringType, nullable =true)) fields: Array[org.apache.spark.sql.types.StructField] = Array(StructField(name,StringType,true...
Spark.Sql.Expressions Microsoft.Spark.Sql.Streaming Microsoft.Spark.Sql.Types Microsoft.Spark.Sql.Types ArrayType AtomicType BinaryType BooleanType ByteType DataType DataType Constructors Properties Json SimpleString TypeName Methods Date DateType DecimalType DoubleType FloatType FractionalType IntegerType ...
Spark应用可以用SparkContext创建DataFrame,所需的数据来源可以是已有的RDD(existing RDD),或者Hive表,或者其他数据源(data sources.) 以下是一个从JSON文件创建DataFrame的小栗子: Scala Java Python R val sc: SparkContext // 已有的 SparkContext. val sqlContext = new org.apache.spark.sql.SQLContext(sc) ...
spark-sql CLI是执行Spark SQL查询的便捷工具。虽然此实用程序在本地模式下与Hive Metastore服务进行通信,但它不会与Thrift JDBC/ODBC 服务(也称为Spark Thrift Server或STS)通信。STS允许JDBC/ODBC客户端在Apache Spark上通过JDBC和ODBC协议执行SQL查询。 要启动Spark SQL CLI,进入$SPARK_HOME文件夹中执行以下命令:...
I read that Spark SQL has three complex data types: ArrayType, MapType, and StructType. When would you use these? I'm confused because I was taught that SQL tables should never, ever contain arrays/lists in a single cell value, so why does Spark SQL allow having arraytype?
Spark SQL DataType class is a base class of all data types in Spark which defined in a package org.apache.spark.sql.types.DataType and they are primarily