importorg.apache.spark.sql.SparkSessionvalspark=SparkSession.builder().appName("JSON to Array Explode Example").getOrCreate()valdata=Seq(("Alice",30,"""["reading", "painting", "traveling"]"""),("Bob",25,"""["swimming", "cooking"]"""))valdf=spark.createDataFrame(data).toDF("name...
Structured Streaming (结构化流)是一种基于SparkSQL 引擎构建的可扩展且容错的 stream processing engine (流处理引擎)。可以使用Dataset/DataFrameAPI来表示 streaming aggregations (流聚合), event-time windows (事件时间窗口), stream-to-batch joins (流到批处理连接) 等。 Dataset/DataFrame在同一个 optimized ...
-- 创建示例数据表 CREATE TABLE example ( id INT, info ARRAY<STRING> ); INSERT INTO example VALUES (1, array('a', 'b', 'c')), (2, array('d', 'e')); -- 使用 LATERAL VIEW 和 explode 函数展开数组 SELECT id, info_value FROM example LATERAL VIEW explode(info) AS inf...
"切为数组,然后用EXPLODE将列转行,并记为t3//4.对推荐的题目进行去重,将t3和t_answer原始表进行join,得到每个推荐的题目所属的科目,记为t4//5.统计各个科目包含的推荐的题目数量并倒序排序(已去重)//===写法1:SQL风格===/*spark.sql( """SELECT | ...
Problem: How to explode & flatten nested array (Array of Array) DataFrame columns into rows using PySpark. Solution: PySpark explode function can be
from B Lateral View explode(array(0, 1, 2)) tmp as suffix ) --打散数据(倾斜key已知) select , _rand, from ( select id , case when id = null then concat(‘SkewData_’, cast(rand() as string)) else id end as id_rand
empty[Long] } } } 测试代码: object ExtractMemberIdsTest { def main(args: Array[String]): Unit = { // 创建流执行环境 val env = StreamExecutionEnvironment.getExecutionEnvironment // 创建表执行环境 val tableEnv = StreamTableEnvironment.create(env) // 注册 UDF tableEnv.createTemporarySystem...
Spark SQL DataFrame Array (ArrayType) Column Working with Spark DataFrame Map (MapType) column Spark SQL – Flatten Nested Struct column Spark – Flatten nested array to single array column [Spark explode array and map columns to rows Spark SQL Functions Spark SQL String Functions Explained Spark...
> SELECT explode_outer(array(10, 20)); 10 20expm1 expm1(expr) - Returns exp(expr) - 1. Examples:> SELECT expm1(0); 0.0factorial factorial(expr) - Returns the factorial of expr. expr is [0..20]. Otherwise, null. Examples:
var resultArray = Array.empty[(Int, Int, Int)] for(column1.size): //遍历计算 result[i] = 对俩数组column1,column2进行某种计算操作 //一个group中第i行的结果 resultArray[i]=(column1[i],column2[i],result[i]) resultArray //返回值 ...