sqlContext.sql("select (CASE WHEN ISNULL(B.age)=false THEN B.age ELSE A.age END ) AS age , AS name from (select * from people01 ) A left join (select * from people02) B on = ").show() sqlContext.sql("select (CASE WHEN ISNULL(B.age)=false THEN B.age ELSE A.age END )...
Spark.Sql 組件: Microsoft.Spark.dll 套件: Microsoft.Spark v1.0.0 傳回true,資料行為 null。 C# 複製 public static Microsoft.Spark.Sql.Column IsNull(Microsoft.Spark.Sql.Column column); 參數 column Column 要套用的資料行 傳回 Column Column 物件 適用於 產品版本 Microsoft.Spark latest ...
// Register the DataFrame as a global temporary viewdf.createGlobalTempView("people")// Global temporary view is tied to a system preserved database `global_temp`spark.sql("SELECT * FROM global_temp.people").show()// +---+---+// | age| name|// +---+---+// |null|Michael|//...
54.pyspark.sql.functions.randn(seed=None) 55.pyspark.sql.functions.reverse(col) 56.pyspark.sql.functions.rtrim(col) 57.pyspark.sql.functions.skewness(col) 58.pyspark.sql.functions.sort_array(col, asc=True) 59.pyspark.sql.functions.split(str, pattern) 60.pyspark.sql.functions.sqrt(col) 61.p...
Row): Double = buffer.getLong(0).toDouble / buffer.getLong(1)}// Register the function to access itspark.udf.register("myAverage", MyAverage)val df = spark.read.json("examples/src/main/resources/employees.json")df.createOrReplaceTempView("employees")df.show()val result = spark.sql("...
.builder = <pyspark.sql.session.Builder object at 0x7f51f134a110>:一个Builder实例 .catalog:一个接口。用户通过它来create、drop、alter、query底层的数据库、table 以及function等 可以通过SparkSession.catalog.cacheTable('tableName'), 来缓存表;通过SparkSession.catalog.uncacheTable('tableName') 来从缓存...
本文从讲解了SQL SERVER中分区表的使用方式。分区表是一个非常强大的功能。使用分区表相对传统的分区视图来说,对于减少DBA的管理工作来说,会更胜一筹! -- 创建分区函数 create partition function fnPartition(Date) as range right for values( ' 2004-01-01 ...
1.sparksql-shell交互式查询 就是利用Spark提供的shell命令行执行SQL 2.编程 首先要获取Spark SQL编程"入口":SparkSession(当然在早期版本中大家可能更熟悉的是SQLContext,如果是操作hive则为HiveContext)。这里以读取parquet为例: 代码语言:javascript 代码运行次数:0 ...
Spark SQL 一、sparkSQL的特点 1.支持多种数据源:hive RDD Partquet JSON JDBC 2.多种性能优化技术:in-memory columnar storage \ byte-code generation \ cost model 动态评估 3.组件扩展性:对
Operations inData Filteringare shown in the following figure. is not null(Expression): Return true if the value ofExpressionis not NULL, otherwise, return false. Operations inData Filteringare shown in the following figure. Previous:Common Spark SQL Syntax Next:Spark SQL Window Function...