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。 GROUPING SETS 可以生成等效于由简单 GROUP BY、ROLLUP 或 CUBE 操作生成的结果。 GROUPING SETS、ROLLUP 或CUBE 的不同组合可以生成等效的结果集。 2、分组汇总--方法实例 SQL SERVER增强了WITH ROLLUP 能...
DECLARE@tTABLE(studentnvarchar(50),classnvarchar(50),gradeint) /*insert some datas*/ INSERTINTO@t SELECTN'孙小美',N'数学',10UNIONALL SELECTN'孙小美',N'语文',20UNIONALL SELECTN'孙小美',N'英语',30UNIONALL SELECTN'阿土伯',N'数学',40UNIONALL SELECTN'阿土伯',N'语文',50UNIONALL SELEC...
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: CREATE TABLE Sales (EmpId IN...
采用GROUPING SETS 是一次性读取所有数据,并在内存中进行聚合操作生成结果,减少IO开销,对CPU和内存消耗增加。但GROUPING SETS 在多列分组时,其性能会比group by高。 这里扫描四次是因为我GROUPBYGROUPING SETS (SEX,[DEPARTMENT],[MONEY],YEAR([CREATEDATE]),()) 了四列 ROLLUP与CUBE ROLLUP与CUBE 按一定的规则...
【SQL SERVER 2008 GROUP BY 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。GROUPING SETS 可以生成等效于由简单 GROUP BY、ROLLUP 或 CUBE 操作生成的结果。GROUPING SETS、ROLLUP 或 CUBE 的不同组合可以生成等效的结果集。
SQL SERVER 2008的Grouping sets的用法 CREATE TABLE Sales (EmpId INT, Yr INT, Sales MONEY) INSERT Sales VALUES(1, 2005, 12000) INSERT Sales VALUES(1, 2006, 18000) INSERT Sales VALUES(1, 2007, 25000) INSERT Sales VALUES(2, 2005, 15000)...
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 ...
Transact-SQL 语法约定 语法 syntaxsql GROUPING(<column_expression>) 参数 <column_expression> 列或者GROUP BY子句中包含列的表达式。 返回类型 tinyint 备注 GROUPING 用于区分标准空值和由 ROLLUP、CUBE 或 GROUPING SETS 返回的空值。 作为 ROLLUP、CUBE 或 GROUPING SETS 操作结果返回的 NULL 是 NULL 的特殊应...
As usual, it's time you wrote a query yourself! Exercise Show how much was spent on average for eachCategoryon each day, on each day in general, and in general among all days and categories. Show the following columns:GroupingId(depending on theDeliveryDateandCategory, respectively),...
In the following example, the simple GROUP BY returns a result set to compare to the result sets of examples B through K. These examples use the GROUP BY operators with the same SELECT statement. Copy USE AdventureWorks2008R2; GO SELECT T.[Group] AS N'Region', T.CountryRegionCode AS ...