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。 ld[]f*RuW
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一、基础 <z)MV
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1、说明:创建数据库 b)w3
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CREATE DATABASE database-name Ze Shn
2、说明:删除数据库
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drop database dbname 4'9h^C&
3、说明:备份sql server i`8!Vm
--- 创建 备份数据的 device :eQxdi'
USE master /IV:JVT
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' x)vYc36H
--- 开始 备份 {Rw~G&vQ
BACKUP DATABASE pubs TO testBack a$t [}D2
4、说明:创建新表 _I|wp<R
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) S_2I8G^A
根据已有的表创建新表: e@^}y4
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A:create table tab_new like tab_old (使用旧表创建新表) &[\rnJ?D
B:create table tab_new as select col1,col2... from tab_old definition only ZVIBmx
5、说明:删除新表 iJrscy-
drop table tabname o
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6、说明:增加一个列 +bf%]
Alter table tabname add column col type |klL KX&
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 6nGDoW#
7、说明:添加主键: Alter table tabname add primary key(col) rzaEVXbz1
说明:删除主键: Alter table tabname drop primary key(col) web&M!-
8、说明:创建索引:create [unique] index idxname on tabname(col....) l/rhA6kEU
删除索引:drop index idxname gYzKUX@
注:索引是不可更改的,想更改必须删除重新建。 9f l !CG
9、说明:创建视图:create view viewname as select statement N}FG%a
删除视图:drop view viewname !FpMO`m
10、说明:几个简单的基本的sql语句 4
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选择:select * from table1 where 范围 e$>5GM
插入:insert into table1(field1,field2) values(value1,value2) }>frK#S
删除:delete from table1 where 范围 \wDOE(>
更新:update table1 set field1=value1 where 范围 nI_Zk.R
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! V(!b!i@
排序:select * from table1 order by field1,field2 [desc] _9
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总数:select count as totalcount from table1 y'yaCf
求和:select sum(field1) as sumvalue from table1 ha8do^x
平均:select avg(field1) as avgvalue from table1 -U/&3
最大:select max(field1) as maxvalue from table1 ^2^ptQj
最小:select min(field1) as minvalue from table1 q9WSQ$:z8
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11、说明:几个高级查询运算词 H#Og0gEE}5
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A: UNION 运算符 eIqj7UY_
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 bNaJ{Dm$R
B: EXCEPT 运算符 4a2&kIn
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。 KP<J~+_ik
C: INTERSECT 运算符 5E!|-xD
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。 ^jmnE.8R
注:使用运算词的几个查询结果行必须是一致的。 /
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12、说明:使用外连接
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A、left outer join: Fsq S)
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。 IG9Q~7@
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 [?IERE!xQ
B:right outer join: h0^V!.-5
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。 caj)
C:full outer join: nW drVT$
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。 \GvVs
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二、提升 l'W+^
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) #c^Q<&B
法一:select * into b from a where 1<>1 g&Z7h4!\
法二:select top 0 * into b from a Y1 P[^ws
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) |g7h#F~
insert into b(a, b, c) select d,e,f from b; i)2))C
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) reA8=>b/
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 `oMeR]~
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. ya{>=
4、说明:子查询(表名1:a 表名2:b) SznE:+
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) +hg\DqO^M
5、说明:显示文章、提交人和最后回复时间 Y/S3)o
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 2*citB{
6、说明:外连接查询(表名1:a 表名2:b) $CmX
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select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c vaj66nV
7、说明:在线视图查询(表名1:a ) IPO[J^#Me
select * from (SELECT a,b,c FROM a) T where t.a > 1; >-w=7,?'?z
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 8`G{1lr4o
select * from table1 where time between time1 and time2 u3wC}Zo
select a,b,c, from table1 where a not between 数值1 and 数值2 ;-?ZI$
9、说明:in 的使用方法 {}pqxouE
select * from table1 where a [not] in ('值1','值2','值4','值6') kppRQ Q*[
10、说明:两张关联表,删除主表中已经在副表中没有的信息 &'7"i~pC
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ~+#--BhV
11、说明:四表联查问题: ?*'$(}r3
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... uit-Q5@~
12、说明:日程安排提前五分钟提醒 UNQRtR/
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 4*vas]
13、说明:一条sql 语句搞定数据库分页 be:phS4vz
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 v\Y}(fD
14、说明:前10条记录 TJXraQK-=
select top 10 * form table1 where 范围 <KwK
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15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) Uk:.2%S2
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 16QbB;
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 z`/.v&<>V
(select a from tableA ) except (select a from tableB) except (select a from tableC) #Q3PzDfj
17、说明:随机取出10条数据 RW7oL:$dt
select top 10 * from tablename order by newid() %?f:"
18、说明:随机选择记录 $a^isd4
select newid() qd+[ShrhqZ
19、说明:删除重复记录 ,Us2UEWNv
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) >J}n@MZ
20、说明:列出数据库里所有的表名 5!ubY
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select name from sysobjects where type='U' HJ qQlEq
21、说明:列出表里的所有的 z"K(
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select name from syscolumns where id=object_id('TableName') q{GSsDo-:V
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 p%"yBpSK
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type ^v!im\ r
显示结果: )_v\{N
type vender pcs )@qup _M@
电脑 A 1 !&`\ LJ=j
电脑 A 1 5$oewjLO
光盘 B 2
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光盘 A 2 <{/;1Dru
手机 B 3 ch>Vv"G>
手机 C 3 lV<Tsk'
23、说明:初始化表table1 20VVOnDY
TRUNCATE TABLE table1 Lq-33#n/
24、说明:选择从10到15的记录 oM<!I0"gC+
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc A*;?U2
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三、技巧 u:k:C
1、1=1,1=2的使用,在SQL语句组合时用的较多 Mjj}E
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"where 1=1" 是表示选择全部 "where 1=2"全部不选, `x}
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如: 3}4p_}f/[4
if @strWhere !='' =#(0)p$EC
begin i7nL_N
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ole|J
end 'qV3O+@MF
else HmExfW
begin &|N%#pYS
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' vWl[l
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end 0zbLc%
我们可以直接写成 }t|Plz
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 7%9)C[6NSs
2、收缩数据库 l>~`;W
--重建索引 T^$g N|
DBCC REINDEX <jUrE[x
DBCC INDEXDEFRAG >`89N'lZBm
--收缩数据和日志 MCeu0e^)
DBCC SHRINKDB 0)AM-/"
DBCC SHRINKFILE BF36V\
3、压缩数据库 HK0::6n{
dbcc shrinkdatabase(dbname) vJRnBq+y
4、转移数据库给新用户以已存在用户权限 W7L+8LU;
exec sp_change_users_login 'update_one','newname','oldname' 4TUtY:
go @H\pipT_b
5、检查备份集 H#L#2M%
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' IyS"
6、修复数据库 uxOJ3
ALTER DATABASE [dvbbs] SET SINGLE_USER K 3Yw8t2J
GO $_C+4[R?
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK URK!W?3c
GO L)F1NuR
ALTER DATABASE [dvbbs] SET MULTI_USER 'j,oIqx
GO +2DE/wE]e+
7、日志清除 SY,I>-%
SET NOCOUNT ON yI8m%g%
DECLARE @LogicalFileName sysname, o\ngR\>
@MaxMinutes INT, xQJIM.
@NewSize INT VLsh=v
USE tablename -- 要操作的数据库名 dL_QX,X-]
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 =4tO0
@MaxMinutes = 10, -- Limit on time allowed to wrap log. /vjGjb=3U
@NewSize = 1 -- 你想设定的日志文件的大小(M) \sK:W|yy
-- Setup / initialize 5vTv$2@
DECLARE @OriginalSize int U:]MgZWn
SELECT @OriginalSize = size AkrTfi4hC
FROM sysfiles ZXsYn
WHERE name = @LogicalFileName 1")FWN_K/T
SELECT 'Original Size of ' + db_name() + ' LOG is ' + p9-0?(]
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + M8';%=@
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' G#H9g PY
FROM sysfiles !4R>O6k
WHERE name = @LogicalFileName 74K)aA
CREATE TABLE DummyTrans X JY5@I.
(DummyColumn char (8000) not null) vv+D*e&<
DECLARE @Counter INT, *hVb5CS
@StartTime DATETIME,
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@TruncLog VARCHAR(255) 6b?`:$Cw3)
SELECT @StartTime = GETDATE(), <EMkD1e
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' =m}TU)4.
DBCC SHRINKFILE (@LogicalFileName, @NewSize) I>A^I
EXEC (@TruncLog) ]gu1#
-- Wrap the log if necessary. Q|Pbt(44
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired n]+.
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ;XG]Q<S\
AND (@OriginalSize * 8 /1024) > @NewSize .H8mRvd?
BEGIN -- Outer loop. %}C9
SELECT @Counter = 0 &1wpGJqm
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) rA,CQypo
BEGIN -- update Xv0F:1
INSERT DummyTrans VALUES ('Fill Log') D?e"U_
DELETE DummyTrans \a\= gn
SELECT @Counter = @Counter + 1 JO2xT#V
END ->\N_|_
EXEC (@TruncLog) Ap%O~wA'
END fk>l{W}e)
SELECT 'Final Size of ' + db_name() + ' LOG is ' + Z>F@nTzb>
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + .o}%~g <d
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' %[wTz$S"
FROM sysfiles o{V#f_o
WHERE name = @LogicalFileName =7 VCtd/
DROP TABLE DummyTrans :NuR>~
SET NOCOUNT OFF d.`&0
8、说明:更改某个表 -vV'Lw(
exec sp_changeobjectowner 'tablename','dbo' 3DW3LYo{
9、存储更改全部表 2F1ZAl
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch *g1L$FBG
@OldOwner as NVARCHAR(128), *Bs^NU.
@NewOwner as NVARCHAR(128) ic-IN~J-
AS ASW4,% cl
DECLARE @Name as NVARCHAR(128) Ep mJWbU
DECLARE @Owner as NVARCHAR(128) cC%j!8!
DECLARE @OwnerName as NVARCHAR(128) jYWw.g<
DECLARE curObject CURSOR FOR xO7Yt
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select 'Name' = name, iK!dr1:wSw
'Owner' = user_name(uid) vU!8`x)
from sysobjects H`-=?t
where user_name(uid)=@OldOwner vX+.e1m
order by name qD-fw-,:
OPEN curObject [ ?iqqG.
FETCH NEXT FROM curObject INTO @Name, @Owner QH~Jy*\+PX
WHILE(@@FETCH_STATUS=0) G>%AZr{M
BEGIN ?*H9-2W@
if @Owner=@OldOwner 3B{[%#vO
begin ?,07;>&
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ]#zZWg
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exec sp_changeobjectowner @OwnerName, @NewOwner ;i\C]*
end F$Q04Qw
-- select @name,@NewOwner,@OldOwner RN[]Jt#6
FETCH NEXT FROM curObject INTO @Name, @Owner 4T`&Sl
END }c%
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close curObject +8AvTSgX%
deallocate curObject *Y%Jl
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GO n 'K6vW3
10、SQL SERVER中直接循环写入数据 \iru7'S
declare @i int /^:2<y8Ha
set @i=1 Q[PK`*2)
while @i<30 -[DWM2C$K4
begin @2
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insert into test (userid) values(@i) \9)#l#m
set @i=@i+1 9#k0_vDoW
end p@ygne4
小记存储过程中经常用到的本周,本月,本年函数 r`6:Q&&
Dateadd(wk,datediff(wk,0,getdate()),-1) 5&!'^!
Dateadd(wk,datediff(wk,0,getdate()),6) 8o|P&q(v*
Dateadd(mm,datediff(mm,0,getdate()),0) ,Ff n)+
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) gn ?YF`
Dateadd(yy,datediff(yy,0,getdate()),0) eA=WGy@IcN
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) J8<J8x4
上面的SQL代码只是一个时间段 7,'kpyCj
Dateadd(wk,datediff(wk,0,getdate()),-1) ?NG=8.p
Dateadd(wk,datediff(wk,0,getdate()),6) +=eR%|!@
就是表示本周时间段. 51 b y
下面的SQL的条件部分,就是查询时间段在本周范围内的: +Ok%e.\ZM
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 6|!NLwa
而在存储过程中 {38\vX,I(w
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) XE rUS80
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ?Elg?)os