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。 [M6/?4\
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一、基础 #`H^8/!e
1、说明:创建数据库 TID0x/j"K5
CREATE DATABASE database-name kpN'H_ .
2、说明:删除数据库 <=,KP)
drop database dbname =F}e>D
3、说明:备份sql server lCyp&b#(L
--- 创建 备份数据的 device zdUi1 b
USE master 8h2! 8'
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' |!{BjOAD'
--- 开始 备份 ?k:i3$
BACKUP DATABASE pubs TO testBack D0&{iZ(
4、说明:创建新表
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create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ]jzINaMav
根据已有的表创建新表: VSkx;P
A:create table tab_new like tab_old (使用旧表创建新表) V-w[\u
B:create table tab_new as select col1,col2... from tab_old definition only o*u A+7n
5、说明:删除新表 f6P5J|'
drop table tabname hD/bO
6、说明:增加一个列 s"|N-A=cS
Alter table tabname add column col type 8Q1){M9'
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。 ?Y~>H2
7、说明:添加主键: Alter table tabname add primary key(col) I
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说明:删除主键: Alter table tabname drop primary key(col) r(yb%p+
8、说明:创建索引:create [unique] index idxname on tabname(col....) -3r&O:
删除索引:drop index idxname O"mU#3?
注:索引是不可更改的,想更改必须删除重新建。 5aTyM_x
9、说明:创建视图:create view viewname as select statement f:TC;K
删除视图:drop view viewname w`VmN}pR
10、说明:几个简单的基本的sql语句 g5to0
选择:select * from table1 where 范围 sh?Dxodp9
插入:insert into table1(field1,field2) values(value1,value2) ?^&!/,
删除:delete from table1 where 范围 !+H=e>Y6
更新:update table1 set field1=value1 where 范围 bct&ge7YX
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料!
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排序:select * from table1 order by field1,field2 [desc] H2RNekck
总数:select count as totalcount from table1 q#PGcCtu
求和:select sum(field1) as sumvalue from table1 nx,67u/Pb
平均:select avg(field1) as avgvalue from table1 !U/:!e`N
最大:select max(field1) as maxvalue from table1 4#=!VK8ZH
最小:select min(field1) as minvalue from table1 u6jJf@!ws
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11、说明:几个高级查询运算词 e= "/oo
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A: UNION 运算符 &TWO/F+Y
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。 ,l7ty#j
B: EXCEPT 运算符 uD:O[H-x
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。 60AX2-sdJ,
C: INTERSECT 运算符 {Rw~G&vQ
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。 K{>O.5
注:使用运算词的几个查询结果行必须是一致的。 ?67j+)
12、说明:使用外连接 i$:CGUb
A、left outer join: ~`_nw5y
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 PD/JXExK
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c W {dx\+
B:right outer join: 9f,HjRP
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 5I(`
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C:full outer join: bJB:]vs$
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。 s[s 6E`Q
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二、提升 &|E2L1
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) Z^GriL
法一:select * into b from a where 1<>1 p6}jCGJ
法二:select top 0 * into b from a QTn-n)AE
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ha8do^x
insert into b(a, b, c) select d,e,f from b; <U,T*Ql1x
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) 6lWO8j^BN
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 l3iL.?&Pa
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. [sKdIw_
4、说明:子查询(表名1:a 表名2:b) cF vGpZ
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) eIqj7UY_
5、说明:显示文章、提交人和最后回复时间 ^*{xTB57
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b ;:$Na=
6、说明:外连接查询(表名1:a 表名2:b) acGmRP9g
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c #sqDZ]\B
7、说明:在线视图查询(表名1:a ) 3&?Tc|F+
select * from (SELECT a,b,c FROM a) T where t.a > 1; Yaa
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8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 ?4lAL
select * from table1 where time between time1 and time2 %74Ms
select a,b,c, from table1 where a not between 数值1 and 数值2 10}Zoq|)n
9、说明:in 的使用方法 )uX:f8
select * from table1 where a [not] in ('值1','值2','值4','值6') U.^)|IHW
10、说明:两张关联表,删除主表中已经在副表中没有的信息 jZ{S{"j
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) H`Z4a
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11、说明:四表联查问题: ~l}TlRqL
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... 'g=yJ
12、说明:日程安排提前五分钟提醒 ka>RAr J
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 `jZX(H
13、说明:一条sql 语句搞定数据库分页 ~hxB Pn."
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 TM^1{0;r5
14、说明:前10条记录 k=~?!+p7
select top 10 * form table1 where 范围 ,^<+5TYM7
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) %~W}262
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) Iiy:<c
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 y1
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(select a from tableA ) except (select a from tableB) except (select a from tableC) l.34h
17、说明:随机取出10条数据 U|Jo[4A
select top 10 * from tablename order by newid() mm{U5
18、说明:随机选择记录 #VO2O0GR
select newid() eLC&f}
19、说明:删除重复记录 C3b'Q
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) n7MS{`
20、说明:列出数据库里所有的表名 v =?V{"wk!
select name from sysobjects where type='U' cUm9s>^)/
21、说明:列出表里的所有的 U1"t|KW8
select name from syscolumns where id=object_id('TableName') 4KM$QHS5{
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。 @"/}Al
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 g-:)}8d6
显示结果: $@Ay0GEI"
type vender pcs k0YsAa#6V
电脑 A 1 1tr>D:c\
电脑 A 1 FSQ&J|O
光盘 B 2 v]BQIE?R /
光盘 A 2 u:S@'z>
手机 B 3 ;OPCBd r
手机 C 3 6m.Ku13;
23、说明:初始化表table1 w7Pe<vT
TRUNCATE TABLE table1 =Hx~]1
24、说明:选择从10到15的记录 L|2COX
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc O\LW
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三、技巧 4y1>!~f
1、1=1,1=2的使用,在SQL语句组合时用的较多 t@u\ 4bv
"where 1=1" 是表示选择全部 "where 1=2"全部不选, OhW=F2OIV
如: B![5+
if @strWhere !='' ,SyUr/D
begin L@z !,r,
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere }]~}DHYr
end 1SFKP$^
else Hr+-ndH!Pq
begin ob] lCX)
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' )T64(_TE
end tRy
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我们可以直接写成 0 `!Q-G7
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 2&Byq
2、收缩数据库 Ft7a\vn*B
--重建索引 t>wxK
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DBCC REINDEX H{f_:z{{
DBCC INDEXDEFRAG ' 4~5ez|:
--收缩数据和日志 B
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DBCC SHRINKDB 5|R2cc|"9
DBCC SHRINKFILE N4To#Q1w
3、压缩数据库 ^)q2\YE;
dbcc shrinkdatabase(dbname) mei_aN7zW
4、转移数据库给新用户以已存在用户权限 .UrYF 0
exec sp_change_users_login 'update_one','newname','oldname' ;-?ZI$
go PEBFN
5、检查备份集 >fye^Tx
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ?*'$(}r3
6、修复数据库 %;Z bQ9
ALTER DATABASE [dvbbs] SET SINGLE_USER X[Ek'=}
GO ~RXpz-Ye
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK Ys$YI{
GO Tq84Fn!HJ>
ALTER DATABASE [dvbbs] SET MULTI_USER "rGOw'!q>
GO jAK{<7v4U
7、日志清除
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SET NOCOUNT ON *yaX:,'\$
DECLARE @LogicalFileName sysname, M%{?\)s
@MaxMinutes INT, (b%y$D
@NewSize INT zw:C*sY
USE tablename -- 要操作的数据库名 b#g
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SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 p%"yBpSK
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ZCBPO~&hO'
@NewSize = 1 -- 你想设定的日志文件的大小(M) ~u0xXfv#
-- Setup / initialize %kx
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DECLARE @OriginalSize int HB7(
SELECT @OriginalSize = size
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FROM sysfiles P;[Y42\z|
WHERE name = @LogicalFileName ]&:b<]K3
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 3l%,D:
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CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + |:9Ir^
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' "W@XP+POAY
FROM sysfiles o}=.
WHERE name = @LogicalFileName :B=8_M
CREATE TABLE DummyTrans ^%8qKC`Tt
(DummyColumn char (8000) not null) s^>lOQ=
DECLARE @Counter INT, b(RBG
@StartTime DATETIME, h/Hl?O8[
@TruncLog VARCHAR(255) h.V]f S
SELECT @StartTime = GETDATE(),
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@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' zBt`L,^
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 0zbLc%
EXEC (@TruncLog) [8@kx Cq
-- Wrap the log if necessary. ]G0dS
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired h}|6VJ@.
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) %f(S'<DhC
AND (@OriginalSize * 8 /1024) > @NewSize e8WEz
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BEGIN -- Outer loop. lRDxIuTK
SELECT @Counter = 0 wn+j39y?ZY
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ejklpa ./
BEGIN -- update 4TUtY:
INSERT DummyTrans VALUES ('Fill Log') SFn 3$ rh
DELETE DummyTrans ~XUOW Y75
SELECT @Counter = @Counter + 1 .Z=Ce!
END BR36}iS;V
EXEC (@TruncLog) 'Y!pY]Z
END wmo{YS3t|
SELECT 'Final Size of ' + db_name() + ' LOG is ' +
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CONVERT(VARCHAR(30),size) + ' 8K pages or ' + Sty!atEWT
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' o\ngR\>
FROM sysfiles R-pH Quu3
WHERE name = @LogicalFileName 4.|-m.a
DROP TABLE DummyTrans Wp5]Uk
SET NOCOUNT OFF sEce{"VC
8、说明:更改某个表 [$l"-*s4
exec sp_changeobjectowner 'tablename','dbo' 6F`qi:a+
9、存储更改全部表 $Z;B QJVH
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch TMJ9~"IO
@OldOwner as NVARCHAR(128), fcRj
@NewOwner as NVARCHAR(128) r C_d$Jv
AS b~_B
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DECLARE @Name as NVARCHAR(128) e?V,fzg
DECLARE @Owner as NVARCHAR(128) ]@X{dc
DECLARE @OwnerName as NVARCHAR(128) 6&89~W{
DECLARE curObject CURSOR FOR '>3`rsu
select 'Name' = name, &%^K,Q"
'Owner' = user_name(uid) .^i<xY
from sysobjects __!m*!sd
where user_name(uid)=@OldOwner -bypuMQ-p
order by name n]+.
OPEN curObject (I4y[jnD
FETCH NEXT FROM curObject INTO @Name, @Owner 1SW4Y
WHILE(@@FETCH_STATUS=0) ./l|8o
BEGIN P,i"&9 8
if @Owner=@OldOwner .f>,6?
begin &p5&=zV}
set @OwnerName = @OldOwner + '.' + rtrim(@Name) TPHYz>D]
exec sp_changeobjectowner @OwnerName, @NewOwner 8xgJSk
end Dl%?OG<
-- select @name,@NewOwner,@OldOwner u4YM^* S.
FETCH NEXT FROM curObject INTO @Name, @Owner @\)fzubu
END 14H'!$
close curObject vMhYpt?7\
deallocate curObject tBseqS3<
GO cw;co@!$
10、SQL SERVER中直接循环写入数据 `<^*jB@P
declare @i int Z,WubX<
set @i=1 ASW4,% cl
while @i<30 o(qEkR:4kd
begin jYWw.g<
insert into test (userid) values(@i) 3 jF|Ic
set @i=@i+1 f&ytK
end ==N` !+
小记存储过程中经常用到的本周,本月,本年函数 !hCS#'
Dateadd(wk,datediff(wk,0,getdate()),-1) P-'_}*wxi
Dateadd(wk,datediff(wk,0,getdate()),6) vX+.e1m
Dateadd(mm,datediff(mm,0,getdate()),0) WL l_'2h
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) h4(JUio
Dateadd(yy,datediff(yy,0,getdate()),0) 7^MX l
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) \ZSTKi?
上面的SQL代码只是一个时间段 )~V}oKk0t
Dateadd(wk,datediff(wk,0,getdate()),-1) Jx$iwu
Dateadd(wk,datediff(wk,0,getdate()),6) 0(gq;H5x'
就是表示本周时间段. Nb;H`<JP
下面的SQL的条件部分,就是查询时间段在本周范围内的: ',ZF5T5z@
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) FXahZW~Ol
而在存储过程中 ^s{hs(8%R
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) _s+c+]bO
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ZenPw1 -