SQL语句先前写的时候,很容易把一些特殊的用法忘记,我特此整理了一下SQL语句操作。 %f1IV(3Qc
4*5 e0:O
^=1u2YdVw
一、基础 -o!bO9vC
1、说明:创建数据库 LEOa=(mN\
CREATE DATABASE database-name l+hOD{F4pS
2、说明:删除数据库 Em5,Zr_
drop database dbname 'd&4MA 0X
3、说明:备份sql server Ryxu#]s
--- 创建 备份数据的 device ;'08-Et
USE master yx:+Xy*N
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' Y5;afU='
--- 开始 备份 _9p79S<+
BACKUP DATABASE pubs TO testBack W|uRQA`
4、说明:创建新表 u4m8^fj+T
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) YG8)`XqC
根据已有的表创建新表: 7l~^KsX
A:create table tab_new like tab_old (使用旧表创建新表) *,*O.#<6
B:create table tab_new as select col1,col2... from tab_old definition only ~kSOYvK$'
5、说明:删除新表 .9,x_\|G*
drop table tabname "bWx<
6、说明:增加一个列 lQvgq
Alter table tabname add column col type o)7Ot\:E
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 `YE=B{q
7、说明:添加主键: Alter table tabname add primary key(col) S7#dyAX8
说明:删除主键: Alter table tabname drop primary key(col) j|N<6GSke
8、说明:创建索引:create [unique] index idxname on tabname(col....) a l6y=;\jZ
删除索引:drop index idxname #d/T7c#
注:索引是不可更改的,想更改必须删除重新建。 ~UNha/nt
9、说明:创建视图:create view viewname as select statement bqp^\yu-E
删除视图:drop view viewname $8AW
10、说明:几个简单的基本的sql语句 $|3zsi2
选择:select * from table1 where 范围 @pYC!;n+
插入:insert into table1(field1,field2) values(value1,value2) la!U
删除:delete from table1 where 范围 -"i$^Q`
更新:update table1 set field1=value1 where 范围 wAX;)PLg
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ">eled)O
排序:select * from table1 order by field1,field2 [desc] !IO\g"y~|%
总数:select count as totalcount from table1 N mxh zjJ
求和:select sum(field1) as sumvalue from table1 lcjOBu
平均:select avg(field1) as avgvalue from table1 -qHG*v,
最大:select max(field1) as maxvalue from table1 j6XHH&ZEb
最小:select min(field1) as minvalue from table1 m.1-[ 2{8~
X# ud5h
v>Kh5H5e~
-38"S;M8
11、说明:几个高级查询运算词 o^*:
pL`Q+}c}
-;&I S
A: UNION 运算符 O"\_%=X9
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 :
xggo
B: EXCEPT 运算符 vq+CW?*"
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 o9]32l
C: INTERSECT 运算符 rBi<Yy$z
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 r `n|fD.
注:使用运算词的几个查询结果行必须是一致的。 {#4a}:3
12、说明:使用外连接 0R[fH
A、left outer join: XBkaum4j
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 S<cz2FlV
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 0j6b5<Gpc*
B:right outer join: L%Rw]=v}v
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 eB1NM<V
C:full outer join: D M+MBK
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 e!gNd>b {
_X;,,VEV!
ZeU){CB
二、提升 wCR! bZ w
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ecoI-@CAI
法一:select * into b from a where 1<>1 T#E$sZ
法二:select top 0 * into b from a YGLq~A
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) k3@d
=k
insert into b(a, b, c) select d,e,f from b; i$@xb_
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) D6&P9e_5
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 jl(D;JnF
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. DrV[1Z
4、说明:子查询(表名1:a 表名2:b) S#B%[3@
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) x$n.\`f0
5、说明:显示文章、提交人和最后回复时间 L8f+uI
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b -s`Wd4AP
6、说明:外连接查询(表名1:a 表名2:b) a3\~AO H%
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ecJjE
56P
7、说明:在线视图查询(表名1:a ) 1hgIR^;[b
select * from (SELECT a,b,c FROM a) T where t.a > 1; ,pdzi9@=t
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 ]BbV\#
select * from table1 where time between time1 and time2 U:n~S
select a,b,c, from table1 where a not between 数值1 and 数值2 CLVT5pj='
9、说明:in 的使用方法 _|0#
select * from table1 where a [not] in ('值1','值2','值4','值6') FK~wr;[
10、说明:两张关联表,删除主表中已经在副表中没有的信息 rOt{bh6r
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) %7aJSuQN%
11、说明:四表联查问题: T&>65`L
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... r"h09suZBW
12、说明:日程安排提前五分钟提醒 24? _k]Y
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 FZ+2{wIV^
13、说明:一条sql 语句搞定数据库分页 R8u8jG(4
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段
aY(s
&
14、说明:前10条记录 DT>`.y%2W
select top 10 * form table1 where 范围 SM
RKEPwp&
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) )D6i {I0
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) [7gz?9VyLF
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 xW5 `.^5
(select a from tableA ) except (select a from tableB) except (select a from tableC) Ao` e{
17、说明:随机取出10条数据 IE996
select top 10 * from tablename order by newid() Oy=0Hsh@x
18、说明:随机选择记录 %M'`K
select newid() wzwv>@}
19、说明:删除重复记录 \i//Aq
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) 8w:mL^6x
20、说明:列出数据库里所有的表名 __QnzEF
select name from sysobjects where type='U' 6V1oZ-:}
21、说明:列出表里的所有的 3))R91I
select name from syscolumns where id=object_id('TableName') Ua
6O~,\
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 ;7?oJH;
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type H,w8+vZ4\
显示结果: wZ\93W-}
type vender pcs &ZC{ _t
电脑 A 1 1R~$m
电脑 A 1 6O6B8
光盘 B 2 L%5y@b{AR
光盘 A 2 nKr'cb
手机 B 3 .u#Hg'o P
手机 C 3 wUr(i *
23、说明:初始化表table1 p19(>|$J
TRUNCATE TABLE table1 .$x}~Sw
24、说明:选择从10到15的记录 9v*y&V9/
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc @Q2E1Uu%
!J#P'x0
^$O(oE(D
__$ ;Z
三、技巧 D3dh,&KO\
1、1=1,1=2的使用,在SQL语句组合时用的较多 Bl6I@w
"where 1=1" 是表示选择全部 "where 1=2"全部不选, >"<s7$g
如:
&R4?]I
if @strWhere !='' Tb?X KO,
begin _zM?"16I}
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere KNQj U-A
end Y_ne?/sZE
else t!/~_}eD J
begin gsM$VaF(
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' M*3G
end %pOz%v~
我们可以直接写成 SWI\;:k
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere dazML|1ow
2、收缩数据库
gvo98Id
--重建索引 NR_3nt^h
DBCC REINDEX 2D"my]FnF
DBCC INDEXDEFRAG `V V>AA5
--收缩数据和日志 iz/CC V L
DBCC SHRINKDB P}gtJ;
DBCC SHRINKFILE vjm? X
3、压缩数据库 `^8mGR>OpI
dbcc shrinkdatabase(dbname) a1I-d=]
4、转移数据库给新用户以已存在用户权限 Ar/P%$Zfq
exec sp_change_users_login 'update_one','newname','oldname' LsIZeL^
go !BkE-9v?w
5、检查备份集 }DjVZ48
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' !\%JOf}
6、修复数据库 $+44US
ALTER DATABASE [dvbbs] SET SINGLE_USER 13v`rK`7o
GO N-F&=u}
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 1/:vFX
GO 6-"tQ,AZ
ALTER DATABASE [dvbbs] SET MULTI_USER diM*jN#
GO s,[I_IiPf
7、日志清除 -nC&t~sD
SET NOCOUNT ON e> 9X
DECLARE @LogicalFileName sysname, 7lwI]/ZH*
@MaxMinutes INT, CckfoJ 9
@NewSize INT Sft
vN-
USE tablename -- 要操作的数据库名 |-\anby<
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 $=E4pb4Y
@MaxMinutes = 10, -- Limit on time allowed to wrap log. mMZ{W+"[f
@NewSize = 1 -- 你想设定的日志文件的大小(M) W9c&"T9JT
-- Setup / initialize ZR3,dW6S
DECLARE @OriginalSize int X4hz\={
SELECT @OriginalSize = size [T7&)p
FROM sysfiles EmUn&p%hI
WHERE name = @LogicalFileName [&&#~gz
SELECT 'Original Size of ' + db_name() + ' LOG is ' + }15&<s
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ~$4(|Fq/
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' UYZC% $5x
FROM sysfiles P(8Yz W
WHERE name = @LogicalFileName vS5}OV
CREATE TABLE DummyTrans 6vNn;-gg.
(DummyColumn char (8000) not null) %4x0^<k~
DECLARE @Counter INT, %{r3"Q=;W
@StartTime DATETIME, zB+e;x f |
@TruncLog VARCHAR(255) C,>n
SELECT @StartTime = GETDATE(), oupWzjo
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' yxpv;v:)=
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ceks~[rP
EXEC (@TruncLog) o!+'<IQ'
-- Wrap the log if necessary. !fAvxR
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired xV14Y9
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) .bp#YU,m
AND (@OriginalSize * 8 /1024) > @NewSize 58#nYt
BEGIN -- Outer loop. 0#Ug3_dfr
SELECT @Counter = 0 *(r9c(x a
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ERK{smL
BEGIN -- update ]-#/wC[$l=
INSERT DummyTrans VALUES ('Fill Log') _,K[kVn
DELETE DummyTrans mGDc,C=5:
SELECT @Counter = @Counter + 1 Nes|4Z<
END 4pXY7+e2'
EXEC (@TruncLog) /O.q4p
END R{A$|Ipaq
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 8b7I\J`
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + qrw*?6mSQ
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' =eW4?9Uq
FROM sysfiles
'Bt!X^
WHERE name = @LogicalFileName NkGtZ.!pk
DROP TABLE DummyTrans >+i+_^]
SET NOCOUNT OFF SFuSM/Pf
8、说明:更改某个表 Ei]SksV>*
exec sp_changeobjectowner 'tablename','dbo' b g0ix"
9、存储更改全部表 Q-R?y+| x
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch O z(=%oS
@OldOwner as NVARCHAR(128), o+}1M
@NewOwner as NVARCHAR(128) X~o;jJC
AS 'NjeF6
DECLARE @Name as NVARCHAR(128) #G0'Q2
DECLARE @Owner as NVARCHAR(128) ~0-)S@
DECLARE @OwnerName as NVARCHAR(128) =(TMcu$4`
DECLARE curObject CURSOR FOR ckP AH E@
select 'Name' = name, @Q ~;@M
'Owner' = user_name(uid) It/'R-H
from sysobjects 7W4m&+
where user_name(uid)=@OldOwner $;ny`^8
order by name |p*cI @
OPEN curObject pQ7elv]
FETCH NEXT FROM curObject INTO @Name, @Owner @zw&-b:qI
WHILE(@@FETCH_STATUS=0) o\Fv~^
BEGIN 6A>bm{`c:
if @Owner=@OldOwner ,s}&|+
'"
begin uInI{>
set @OwnerName = @OldOwner + '.' + rtrim(@Name) M{)eA<6
exec sp_changeobjectowner @OwnerName, @NewOwner A\7sP =
end _f>)G3p
-- select @name,@NewOwner,@OldOwner QRl+7V
FETCH NEXT FROM curObject INTO @Name, @Owner d?YSVmG
END sLTQm*jL
close curObject dQp>z%L)
deallocate curObject -3d`e2^&}
GO :si&A;k
10、SQL SERVER中直接循环写入数据 ^o q|^O
declare @i int L?8OWLjRy
set @i=1 k{X+Y6'ku
while @i<30 G^L9[c= ,
begin S%?>Mh?g
insert into test (userid) values(@i) &dw=jHt
set @i=@i+1 c@]G;> o
end D2o|.e<r
小记存储过程中经常用到的本周,本月,本年函数 XD!}uDZ^
Dateadd(wk,datediff(wk,0,getdate()),-1) ]-X\n
Dateadd(wk,datediff(wk,0,getdate()),6) r0&LjH&R
Dateadd(mm,datediff(mm,0,getdate()),0) (C`nBiL<
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) {4[dHfIy
Dateadd(yy,datediff(yy,0,getdate()),0) 9"B;o
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) q:jv9eL.O
上面的SQL代码只是一个时间段 lQ[JA[
Dateadd(wk,datediff(wk,0,getdate()),-1) K'"s9b8
Dateadd(wk,datediff(wk,0,getdate()),6) Mjl,/-0 w
就是表示本周时间段. dYwEVu6q
下面的SQL的条件部分,就是查询时间段在本周范围内的: 9~K>c
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) U/v)6:j)4R
而在存储过程中 X9" T(`
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) fD_3lbiL(
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) rniL+/-uU