情景一：
表中數(shù)據(jù)
name score
aaa 11
aaa 19
bbb 12
bbb 18
ccc 19
ddd 21
期望查詢結(jié)果如下
name score
aaa 30
bbb 30
ccc 19
ddd 21
復(fù)制代碼代碼如下:
---檢查表是否存在
if exists(select * from sysobjects where name='testSum')
drop table testSum
go
---創(chuàng)建表
create table testSum
(
tid int primary key identity(1,1),
tname varchar(30) null,
tscor int null
)
go
insert into testSum (tname,tscor)
select 'aaa',11
union all
select 'aaa',19
union all
select 'bbb',12
union all
select 'bbb',18
union all
select 'ccc',19
union all
select 'ddd',21
---查詢語句
select tname ,sum(tscor) from testSum group by tname
---只查詢tscor總和為30的
select tname ,sum(tscor) from testSum group by tname having sum(tscor)=30
情景二：
姓名 科目 分數(shù)
張三 語文 30
張三 數(shù)學(xué) 50
張三 英語 70
李四 語文 50
李四 數(shù)學(xué) 80
李四 英語 90
期望查詢結(jié)果：
姓名 語文 數(shù)學(xué) 英語
張三 30 50 70
李四 50 80 90
復(fù)制代碼代碼如下:
---檢查表是否存在
if exists(select * from sysobjects where name='testScore')
drop table testScore
go
---創(chuàng)建表
create table testScore
(
tid int primary key identity(1,1),
tname varchar(30) null,
ttype varchar(10) null,
tscor int null
)
go
---插入數(shù)據(jù)
insert into testScore values ('張三','語文',90)
insert into testScore values ('張三','數(shù)學(xué)',20)
insert into testScore values ('張三','英語',50)
insert into testScore values ('李四','語文',30)
insert into testScore values ('李四','數(shù)學(xué)',47)
insert into testScore values ('李四','英語',78)
---查詢
select tname as '姓名' ,
max(case ttype when '語文' then tscor else 0 end) '語文',
max(case ttype when '數(shù)學(xué)' then tscor else 0 end) '數(shù)學(xué)',
max(case ttype when '英語' then tscor else 0 end) '英語'
from testScore
group by tname
情景三：
表:table1
字段：id , name
內(nèi)容：
----------------
1,aaa
1,bbb
2,ccc
2,ddd
3,eee
3,fff
--------------
希望結(jié)果：
---------------------
1 aaa bbb [aaa bbb之間半角空格區(qū)分，以下類似]
2 ccc ddd
3 eee fff
復(fù)制代碼代碼如下:
f exists(select * from sysobjects where name='test1')
drop table test1
go
create table test1
(
tid int primary key identity(1,1),
tnum int null,
tname varchar(30) null
)
go
insert into test1 values (1,'aa')
insert into test1 values (1,'bb')
insert into test1 values (2,'cc')
insert into test1 values (2,'dd')
insert into test1 values (3,'ee')
insert into test1 values (3,'ff')
SELECT * FROM ( SELECT DISTINCT tnum FROM test1
)A
OUTER APPLY(
SELECT tname= STUFF(REPLACE(REPLACE(
(
SELECT tname FROM test1 N
WHERE tnum = A.tnum
FOR XML AUTO
), '<N tname="', ' '), '"/>', ''), 1, 1, '')
)N
情景四：
我需要將表tb中的數(shù)據(jù)select出來，得到下面第二個表的數(shù)據(jù)，如何寫select語句？
表tb
id a flag class
----------+---------+--------+---------
1 2 1 A
2 2 1 A
3 4 1 A
4 5 2 A
5 3 2 A
6 4 1 A
7 2 1 A
8 3 2 A
9 4 2 A
10 5 3 A
11 5 1 B
12 2 1 B
13 3 1 B
14 4 1 B
15 2 3 B
16 7 3 B
17 3 2 B
18 4 1 B
19 5 1 B
20 2 2 B
21 1 1 B
22 1 1 C
23 2 3 C
24 6 3 C
25 3 2 C
...
需要選取出如下的表，按class列進行分組，a1,a2,a3字段分別為flag=1、2、3時tb表中a字段的求和
選取后
a1 a2 a3 class
-----------+------------+-----------------+--------------
sum(a) sum(a) sum(a) A
sum(a) sum(a) sum(a) B
sum(a) sum(a) sum(a) C
sum(a) sum(a) sum(a) D
sum(a) sum(a) sum(a) E
sum(a) sum(a) sum(a) F
sum(a) sum(a) sum(a) G
復(fù)制代碼代碼如下:
---檢查表是否存在
if exists(select * from sysobjects where name='testFlag')
drop table testFlag
go
---創(chuàng)建表
create table testFlag
(
tid int primary key identity(1,1),
tname varchar(30) null,
tflag int null,
tscor int null
)
go
---插入數(shù)據(jù)
insert into testFlag (tname,tflag,tscor)
select 'aaa',1,11
union all
select 'aaa',2,19
union all
select 'aaa',3,12
union all
select 'aaa',1,18
union all
select 'aaa',2,19
union all
select 'aaa',3,21
union all
select 'bbb',1,11
union all
select 'bbb',2,19
union all
select 'bbb',3,12
union all
select 'bbb',1,18
union all
select 'bbb',2,19
union all
select 'bbb',3,21
----查詢語句
select distinct tname,(select sum(tscor) from testFlag where tflag=1 and testFlag.tname = t.tname) as 'flag1',(select sum(tscor) from testFlag where tflag=2 and testFlag.tname = t.tname) as 'flag2',(select sum(tscor) from testFlag where tflag=3 and testFlag.tname = t.tname) as 'flag3' from testFlag t group by tname,tflag
