从代码本身可以看到,你只在GROUP BY GROUPING SETS子句里指定需要的分组集——其它的一切都由SQL Server搞定。指定的空括号是所谓的Empty Grouping Set,是跨整个表的聚集。当你看STATISTICS IO输出时,你会发现Sales.SalesOrderHeader只被访问了1次!这是和刚才手工实现的巨大区别。 在执行计划里,SQL Server使用了Table...
使用GROUPING SETS 的 GROUP BY 子句可以生成一个等效于由多个简单 GROUP BY 子句的 UNION ALL 生成的结果集,并且其效率比 GROUP BY 要高,SQL Server 2008引入。 1.使用GROUP BY 子句的 UNION ALL 来统计 Staff 表中的性别、部门、薪资、入职年份 SETSTATISTICSIOONSETSTATISTICSTIMEONSELECTN'总人数','',COUNT...
GROUPING SETS 使用GROUPING SETS 的 GROUP BY 子句可以生成一个等效于由多个简单 GROUP BY 子句的 UNION ALL 生成的结果集,并且其效率比 GROUP BY 要高,SQL Server 2008引入。 1.使用GROUP BY 子句的 UNION ALL 来统计 Staff 表中的性别、部门、薪资、入职年份 SETSTATISTICSIOONSETSTATISTICSTIMEONSELECTN'总人...
3 NULL 44000.00 Note that we could also write GROUPING SETS (EmpId, Yr) without the extra set of parenthesis, but the extra parenthesis make the intent of the query more explicit and clearly differentiate the previous query from the following query which just performs a normal aggregation by em...
set是无顺序无重复的集合,{}不等于{{}},因为后者包含一个元素 ... Eleni 0 316 cpupower:Shows and sets processor power related values 2019-12-05 13:59 − 软件包: * sys-power/cpupower Latest version available: 4.13.0 Latest version installed: 4.13.0 Size of files: 67 KiB Homepage:...
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...
SQL 複製 DECLARE @Grouping NVARCHAR(50); DECLARE @GroupingLevel SMALLINT; SET @Grouping = N'CountryRegionCode Total'; SELECT @GroupingLevel = ( CASE @Grouping WHEN N'Grand Total' THEN 15 WHEN N'SalesPerson Total' THEN 14 WHEN N'Store Total' THEN 13 WHEN N'Store SalesPerson Total' THEN...
2017-03-10 13:45 − 1.ROLLUP ROLLUP的作用相当于 SQL> set autotrace on SQL> select department_id,job_id,count(*) 2 from employees 3 group b... bolang100 0 220 GROUP BY中ROLLUP/CUBE/GROUPING/GROUPING SETS使用示例 2013-11-01 18:55 − oracle group by中rollup和cube的区别: Orac...
SQL脚本如下: 1USE[tempdb]2GO3CREATETABLEt_test4(5idINT,6productNameVARCHAR(200) ,7priceMONEY,8numINT,9amountINT,10operatedateDATETIME11)12GO1314--插入随机数据15DECLARE@iINT16DECLARE@randMONEY17DECLARE@dateDATETIME18DECLARE@indexINT19DECLARE@DateBaseINT20SET@date='2012-10-23'21SET@i=122WHILE...
AlterServerConfigurationHadrClusterOptionKind AlterServerConfigurationSetBufferPoolExtensionStatement AlterServerConfigurationSetDiagnosticsLogStatement AlterServerConfigurationSetExternalAuthenticationStatement AlterServerConfigurationSetFailoverClusterPropertyStatement AlterServerConfigurationSetHadrClus...