Sometimes the aggregate functions provided by Spark are not adequate, so Spark has a provision of accepting custom user defined aggregate functions. Before diving into code lets first understand some of the methods of class UserDefinedAggregateFuncti…
转载自:https://blog.csdn.net/u012297062/article/details/52227909 UDF: User Defined Function,用户自定义的函数,函数的输入是一条具体的数据记录,实现上讲就是普通的Scala函数:UDAF:User Defined Aggregation Function,用户自定义的聚合函数,函数本身作用于数据集合,能够在聚合操作的基础上进行自定义操作: 实质上讲,例如说UDF会被Spark SQL中的Catalyst封装成为E…
column "ms.xxx_time" must appear in the GROUP BY clause or be used in an aggregate function ------------------------------------------------------------------------------------------ 有min(), max(), sum(), avg()这些函数可以和group by 语句连在一起用. The SQL GR…
Column 'dbo.tbm_vie_View.ViewID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. https://stackoverflow.com/questions/13999817/reason-for-column-is-invalid-in-the-select-list-because-it…
今天在分组统计的时候pgsql报错 must appear in the GROUP BY clause or be used in an aggregate function,在mysql里面是可以的,但是pgsql报错,我去stackoverflow查询了一下,发现有人遇到过和我一样的问题,这是pgsql一个常见的聚合问题,在SQL3标准以前,选择显示的字段必须出现在在 GROUP BY 中.下面我把问题描述一下: 有一张表叫 makerar,表中记录如下: cname | wmname |…
报错信息: 09-05-2017 09:58:44 CST xxxx_job_1494294485570174 INFO - at org.apache.spark.sql.catalyst.errors.package$.attachTree(package.scala:49) 09-05-2017 09:58:44 CST xxxx_job_1494294485570174 INFO - at org.apache.spark.sql.execution.aggregate.Tungsten…
Aggregate函数 一.源码定义 /** * Aggregate the elements of each partition, and then the results for all the partitions, using * given combine functions and a neutral "zero value". This function can return a different result * type, U, than the type of t…
