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...
If we omit one set of parenthesis from the above query, the meaning changes significantly and we end up separately aggregating by employee and then computing the year and month ROLLUP for all employees. The new GROUPING SETS syntax is available in all of SQL Server 2008 Community Technology ...
Grouping Sets is a new feature in T-SQL in SQL Server 2008. Background People cannot help appreciating the GROUP BY clause whenever they have to get a DISTINCT from any result set. Additionally, whenever any aggregate function is required, the GROUP BY clause is the only solution. There ...
2019-09-23 21:12 −mod补充: 1 = 12 mod 3 1 = 12 mod 4 1 = 12 mod 12(12=3*4) 但是这不是一定的,反例如下: 0 = 24 mod 12 0 = 24 mod 4 0 != 24 mod 48 1. set是无顺序无重复的集合,{}不等于{{}},因为后者包含一个元素 ... ...
By usingGROUPING SETS()we can specify multiple groupings in a single query.GROUPING SETS()generates the result by producing aUNION ALLset of the result sets generated by specified grouping sets. for example, consider below data: –© 2011 – Vishal (http://SqlAndMe.com) ...
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 a UNION ALL where each leg of the UNION ALL operator performs aggregation of each grouping set specified ...
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...
2019-09-23 21:12 −mod补充: 1 = 12 mod 3 1 = 12 mod 4 1 = 12 mod 12(12=3*4) 但是这不是一定的,反例如下: 0 = 24 mod 12 0 = 24 mod 4 0 != 24 mod 48 1. set是无顺序无重复的集合,{}不等于{{}},因为后者包含一个元素 ... ...
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...