Spark SQL 官方文档中SQL Syntax一节对Grouping Sets语句的描述如下: Groups the rows for each grouping set specified after GROUPING SETS. (... 一些举例) This clause is a shorthand for aUNION ALLwhere each leg of theUNION ALLoperator performs aggregation of each grouping set specified in theGROUPIN...
Spark SQL 官方文档中SQL Syntax一节对Grouping Sets语句的描述如下: Groups the rows for each grouping set specified after GROUPING SETS. (... 一些举例) This clause is a shorthand for aUNION ALLwhere each leg of theUNION ALLoperator performs aggregation of each grouping set specified in theGROUPIN...
Spark SQL 官方文档中SQL Syntax一节对Grouping Sets语句的描述如下: Groups the rows for each grouping set specified after GROUPING SETS. (... 一些举例) This clause is a shorthand for aUNION ALLwhere each leg of theUNION ALLoperator performs aggregation of each grouping set specified in theGROUPIN...
本文介绍了在T-SQL中使用GROUPING SETS操作符来实现多种分组聚合结果的合并,避免了使用UNION ALL的繁琐。通过AdventureWorks2012数据库示例,展示了如何汇总每年和每月的收入,并加入总体汇总结果,提升查询效率和代码简洁性。
SQL Server GROUP BY GROUPING SETS Example With grouping sets, we can determine how we want the data to be put together. SELECT Department, Category, SUM(Salary) as Salary FROM EmpSalary GROUP BY GROUPING SETS(Category, Department,(Category, Department),()) ...
还有两个比较重要的函数grouping()和grouping_id(),两者都是用来区分标准值和有ROLLUP、CUBE或GROUPING SETS返回的空值的。 1、GROUPING() 在结果集中,如果GROUPING()返回1则表示是由聚合子句产生的空值,0表示是原有记录里面的空值。 示例: selectcasewhengrouping(sex)='1'then'N/A'elsesexend,sclass,sum(score...
grouping sets sql用法 在SQL中,GROUPING SETS用于将结果按多个维度进行分组,并计算每个维度上的汇总数据。其语法如下: SELECT列1,列2, ...,列n,聚合函数(列) FROM表名 GROUP BY GROUPING SETS (维度1,维度2, ...,维度m); 在GROUPING SETS子句中,可以指定多个维度,每个维度可以是一个单独的列,也可以是...
Spark Analyzer会将cube及rollup转换为普通的grouping sets。 rollup比较简单,直接调用scala的inits方法即可。 /** GROUP BY a, b, c WITH ROLLUP* is equivalent to* GROUP BY a, b, c GROUPING SETS ( (a, b, c), (a, b), (a), ( ) ).* Group Count: N + 1 (N is the number of grou...
本文首先简单介绍 Grouping Sets 的用法,然后以 Spark SQL 作为切入点,深入解析 Grouping Sets 的实现机制。 Spark SQL 是 Apache Spark 大数据处理框架的一个子模块,用来处理结构化信息。它可以将 SQL 语句翻译多个任务在 Spark 集群上执行,允许用户直接通过 SQL 来处理数据,大大提升...
We can nest CUBE and ROLLUP within a GROUPING SETS clause as shorthand for expressing more complex GROUPING SETS. This shorthand is most useful when we have more than three dimensions in our schema. For example, suppose we add a month column to our sales table: ...