sql

create table #tmp
(
  name nvarchar(50),
  [subject] nvarchar(50),
  grade float  
)

insert into  #tmp values('张三' ,'语文',90)
insert into  #tmp values('张三' ,'数学',80)
insert into  #tmp values('张三' ,'英语',75)

insert into  #tmp values('李四' ,'语文',75)
insert into  #tmp values('李四' ,'数学',60)
insert into  #tmp values('李四' ,'英语',85)

insert into  #tmp values('王五' ,'语文',85)
insert into  #tmp values('王五' ,'数学',77)
insert into  #tmp values('王五' ,'英语',99)

select * from #tmp;

select name as 姓名,
AVG(case when [subject]='语文' then grade end) as 语文,
AVG(case when [subject]='数学' then grade end) as 数学,
AVG(case when [subject]='英语' then grade end) as 英语
from #tmp
group by #tmp.name

create table #tmp2 --添加物理、化学
(
   姓名 nvarchar(50),
   物理 float,
   化学 float
)

insert into  #tmp2 values('张三' ,75,80)

insert into  #tmp2 values('李四' ,95,85)

insert into  #tmp2 values('王五' ,90,85)

select * from #tmp2;

select a.姓名,a.语文,a.数学,a.英语,b.物理,b.化学 from (
select name as 姓名,
AVG(case when [subject]='语文' then grade end) as 语文,
AVG(case when [subject]='数学' then grade end) as 数学,
AVG(case when [subject]='英语' then grade end) as 英语
from #tmp
group by #tmp.name) a left join #tmp2 b on a.姓名=b.姓名