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Sql纵向表转为横向表,并分组统计(转)

效果如图所示:测试sql语句如下:复制代码
代码如下: declare @tab table(Class varchar(20),Student
varchar(20),Course varchar(50),Quantity decimal(7,2)); insert into
@tab(Class,Student,Course,Quantity) values(‘A班’,’张三’,’语文’,60);
insert into @tab(Class,Student,Course,Quantity)
values(‘A班’,’张三’,’数学’,70); insert into
@tab(Class,Student,Course,Quantity) values(‘A班’,’张三’,’英语’,80);
insert into @tab(Class,Student,Course,Quantity)
values(‘A班’,’李四’,’语文’,30); insert into
@tab(Class,Student,Course,Quantity) values(‘A班’,’李四’,’数学’,40);
insert into @tab(Class,Student,Course,Quantity)
values(‘A班’,’李四’,’英语’,50); insert into
@tab(Class,Student,Course,Quantity) values(‘B班’,’王五’,’语文’,65);
insert into @tab(Class,Student,Course,Quantity)
values(‘B班’,’王五’,’数学’,75); insert into
@tab(Class,Student,Course,Quantity) values(‘B班’,’王五’,’英语’,85);
insert into @tab(Class,Student,Course,Quantity)
values(‘B班’,’赵六’,’语文’,35); insert into
@tab(Class,Student,Course,Quantity) values(‘B班’,’赵六’,’数学’,45);
insert into @tab(Class,Student,Course,Quantity)
values(‘B班’,’赵六’,’英语’,55); select * from @tab select (case when
Grouping(Class)=1 then ‘总平均’ when Grouping(Student)=1 then ” else
Class end ) as Class ,(case when Grouping(Class)=1 then ” when
Grouping(Student)=1 then ‘平均’ else Student end) as Student ,avg(语文)
as 语文 ,avg(数学) as 数学 ,avg(英语) as 英语 ,avg(总分) as 总分 from (
select Class,Student ,(select isnull(sum(Quantity),0) from @tab where
Class=t.Class and Student=t.Student and Course=’语文’) as ‘语文’
,(select isnull(sum(Quantity),0) from @tab where Class=t.Class and
Student=t.Student and Course=’数学’) as ‘数学’ ,(select
isnull(sum(Quantity),0) from @tab where Class=t.Class and
Student=t.Student and Course=’英语’) as ‘英语’ ,(select
isnull(sum(Quantity),0) from @tab where Class=t.Class and
Student=t.Student) as ‘总分’ from @tab as t group by Class,Student ) as
tempTab group by Class,Student,语文,数学,英语,总分 with rollup having
Grouping(语文)=1 and Grouping(数学)=1 and Grouping(英语)=1

 在写系统尤其是在写课程系统是经常会遇到类似如下纵-横转换,在使用group by
… with cube/rollup + grouping() 来实现是非常容易做到的。

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  1. 用于测试的数据如下:

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declare @tab table(Class varchar(20),Student varchar(20),Course varchar(50),Grades decimal(7,2));
insert into @tab(Class,Student,Course,Grades) values(‘A班’,’张三’,’语文’,60);
insert into @tab(Class,Student,Course,Grades) values(‘A班’,’张三’,’数学’,70);
insert into @tab(Class,Student,Course,Grades) values(‘A班’,’张三’,’英语’,80);
insert into @tab(Class,Student,Course,Grades) values(‘A班’,’李四’,’语文’,30);
insert into @tab(Class,Student,Course,Grades) values(‘A班’,’李四’,’数学’,40);
insert into @tab(Class,Student,Course,Grades) values(‘A班’,’李四’,’英语’,50);
insert into @tab(Class,Student,Course,Grades) values(‘B班’,’王五’,’语文’,65);
insert into @tab(Class,Student,Course,Grades) values(‘B班’,’王五’,’数学’,75);
insert into @tab(Class,Student,Course,Grades) values(‘B班’,’王五’,’英语’,85);
insert into @tab(Class,Student,Course,Grades) values(‘B班’,’赵六’,’语文’,35);
insert into @tab(Class,Student,Course,Grades) values(‘B班’,’赵六’,’数学’,45);
insert into @tab(Class,Student,Course,Grades) values(‘B班’,’赵六’,’英语’,55);

select * from @tab

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