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。 %k4Qx5`?d
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一、基础 1Zc=QJw@
1、说明:创建数据库 ^,I2@OS
CREATE DATABASE database-name F\+AA
2、说明:删除数据库 FhY#3-jH
drop database dbname R&(OWF;~,
3、说明:备份sql server ~wuCa!!A
--- 创建 备份数据的 device EQlb:;j
USE master -(?/95 Y
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' @-[}pZ/
--- 开始 备份 w~v6=^
BACKUP DATABASE pubs TO testBack qzNb\y9G
4、说明:创建新表 })^eaLBR4
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) #[9UCX^=
根据已有的表创建新表: lfDd%.:q4S
A:create table tab_new like tab_old (使用旧表创建新表) _1E c54D
B:create table tab_new as select col1,col2... from tab_old definition only 13F]7l-#
5、说明:删除新表 w;ZT-Fti
drop table tabname <}[ !k<
6、说明:增加一个列 BH {z]a
Alter table tabname add column col type
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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。 'qT;Eht5
7、说明:添加主键: Alter table tabname add primary key(col) {rMf/ RAE
说明:删除主键: Alter table tabname drop primary key(col) k@lJ8(i^qU
8、说明:创建索引:create [unique] index idxname on tabname(col....) \0 h>!u
删除索引:drop index idxname z9IW&f~~P
注:索引是不可更改的,想更改必须删除重新建。 u]NsCHKlT
9、说明:创建视图:create view viewname as select statement c>D~MCNxg
删除视图:drop view viewname UZs '[pm)
10、说明:几个简单的基本的sql语句 Jkj7ty.J
选择:select * from table1 where 范围 kl:/PM^
插入:insert into table1(field1,field2) values(value1,value2) |
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删除:delete from table1 where 范围 y%%VJ}'X!
更新:update table1 set field1=value1 where 范围 >gzM-d
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! [ ?7QmZK
排序:select * from table1 order by field1,field2 [desc] :1 qLRr
总数:select count as totalcount from table1 K!CVS7
求和:select sum(field1) as sumvalue from table1 5B:"$vC{=
平均:select avg(field1) as avgvalue from table1 3v_j*wy
最大:select max(field1) as maxvalue from table1 /Q@4HV
最小:select min(field1) as minvalue from table1 eG(YORkR
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11、说明:几个高级查询运算词 `&c[s%0
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A: UNION 运算符 o`Z3}
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。 aMe&4Q
B: EXCEPT 运算符 IQ\!wWKmY
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。 &_Cc
C: INTERSECT 运算符 >4wigc
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。
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注:使用运算词的几个查询结果行必须是一致的。 'Iw`+=iVz
12、说明:使用外连接 >mA]2gV<a
A、left outer join: Y<W9LF
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。 Bv~^keuj3t
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 }bw^p.ci
B:right outer join: Te}gmt+#%
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。 16Ka>=G
C:full outer join: $=\=80u/
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。 $rj:K)P
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二、提升 {'zS8
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 7#"NKxb
法一:select * into b from a where 1<>1 :|5 m"X\
法二:select top 0 * into b from a sT1OAK\^
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) U3Gg:onuE
insert into b(a, b, c) select d,e,f from b; [\Wl~
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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) moFrNcso
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 Zex~ $r
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. cG0)F%?X?
4、说明:子查询(表名1:a 表名2:b) ^NU_Tp:2^
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) PtuRXx
5、说明:显示文章、提交人和最后回复时间 U>!TM##1QD
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b k8ILo)
6、说明:外连接查询(表名1:a 表名2:b) 4S4MQ
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 3"Oipt+
7、说明:在线视图查询(表名1:a ) STu(I\9
select * from (SELECT a,b,c FROM a) T where t.a > 1; JzywSQ
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 1d49&-N
select * from table1 where time between time1 and time2 <FkaH8,7
select a,b,c, from table1 where a not between 数值1 and 数值2 n5~Dxk
9、说明:in 的使用方法 aO1.9!<v
select * from table1 where a [not] in ('值1','值2','值4','值6') 8HLL3H0
10、说明:两张关联表,删除主表中已经在副表中没有的信息 T$MXsq
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) OcF_x/#
11、说明:四表联查问题: |g{50r'=
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 ..... l5^Q
12、说明:日程安排提前五分钟提醒 Yl au
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 W<&/5s
13、说明:一条sql 语句搞定数据库分页 ^-?^iWQG
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 (BH<\&yHE
14、说明:前10条记录 n+=7u[AZi
select top 10 * form table1 where 范围 ).,twf58
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.) Nz{qu}dt
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) &0T7Uv-`
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 v,Kum<oi?
(select a from tableA ) except (select a from tableB) except (select a from tableC) *j(fk[,i
17、说明:随机取出10条数据 ,DHH5sDCn
select top 10 * from tablename order by newid() ?@x$ h
18、说明:随机选择记录 .mrv"k\<
select newid() 1H">Rb30@
19、说明:删除重复记录 P2ySjgd
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) u=@zYA(
20、说明:列出数据库里所有的表名 ]2"UR_x
select name from sysobjects where type='U' $U ._4
21、说明:列出表里的所有的 6E_~8oEl
select name from syscolumns where id=object_id('TableName') ]+pE1-p\
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 =4x6v<
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type \``w>Xy8
显示结果: F',1R"/}
type vender pcs PQ!'<
电脑 A 1 ysp,:)-%G@
电脑 A 1 =1>G*
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光盘 B 2 G@D8[
光盘 A 2 76[qFz
手机 B 3 o}waJN`yI
手机 C 3 2@_3V_
23、说明:初始化表table1 vbd
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TRUNCATE TABLE table1 nY;Sk#9
24、说明:选择从10到15的记录 ~,F]~|U7l
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc #bGYHN
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三、技巧 ;X;x.pi
1、1=1,1=2的使用,在SQL语句组合时用的较多 Z1W%fT
"where 1=1" 是表示选择全部 "where 1=2"全部不选, :1t&>x=T
如: p{qA%D
if @strWhere !='' 8M3DG=D
begin oVUsI,8
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere CPsl/.$tC
end {1UU `d
else [xfg6
begin M4?>x[Pw
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' nRq[il0 `i
end Xq"9TYf$
我们可以直接写成 x=K'Jj
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere a]V#mF |{
2、收缩数据库 `mZ1!I-T
--重建索引 [G+@[9hn%
DBCC REINDEX U\{I09@E 0
DBCC INDEXDEFRAG [4;_8-[Nv
--收缩数据和日志 B2BG*xa
DBCC SHRINKDB OPq6)(Q
DBCC SHRINKFILE &j'k9C2p
3、压缩数据库 kMzDmgoxNg
dbcc shrinkdatabase(dbname) *
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4、转移数据库给新用户以已存在用户权限 k_^
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exec sp_change_users_login 'update_one','newname','oldname' p8s%bPjK
go b<r*EY
5、检查备份集 [r]<~$
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' pR*3Q@Ng
6、修复数据库 Bd>ATc+580
ALTER DATABASE [dvbbs] SET SINGLE_USER m=pH G
GO RAEN
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DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK &QHmo*
GO TgRG6?#^l
ALTER DATABASE [dvbbs] SET MULTI_USER DB jUHirK
GO Q[`2?j?
7、日志清除 .Xxxz
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SET NOCOUNT ON `N7erM
DECLARE @LogicalFileName sysname, &8%^o9sH
@MaxMinutes INT, Iw$T'I+4W
@NewSize INT z __#PQ,n
USE tablename -- 要操作的数据库名 Uq%|v
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 "$"<AKCwS
@MaxMinutes = 10, -- Limit on time allowed to wrap log. rTC| 8e
@NewSize = 1 -- 你想设定的日志文件的大小(M) ~Wm'~y>
-- Setup / initialize g*9&3ov
DECLARE @OriginalSize int 8z&/{:Z@pH
SELECT @OriginalSize = size Br$/hn=
FROM sysfiles '/ueY#eG
WHERE name = @LogicalFileName x1CMW`F
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 4^6Oh#p0
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + Z
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' FNl^ lj`Y
FROM sysfiles rhQO#_`
WHERE name = @LogicalFileName $Ixd;`l*
CREATE TABLE DummyTrans da8
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(DummyColumn char (8000) not null) ~Ty6]A
DECLARE @Counter INT, hg+;!|ha
@StartTime DATETIME, FFN.9[Ly
@TruncLog VARCHAR(255) LXe'{W+bk
SELECT @StartTime = GETDATE(), s, #$o3
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' <dk9n}y<,
DBCC SHRINKFILE (@LogicalFileName, @NewSize) !C.{nOfyv
EXEC (@TruncLog) G<*h,'B
-- Wrap the log if necessary. ,=%c
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired )pey7-P7g5
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) FQJFq6l
AND (@OriginalSize * 8 /1024) > @NewSize 2NL|_W/
BEGIN -- Outer loop. ;ov}%t>UD
SELECT @Counter = 0 DEv,!8
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) _B ]Bd@<w
BEGIN -- update 3
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INSERT DummyTrans VALUES ('Fill Log') #)6
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DELETE DummyTrans b\t@vMJ
SELECT @Counter = @Counter + 1 r7)iNTQ1
END mL,{ZL ^
EXEC (@TruncLog) NXE1v~9V
END "yXqf%CGE
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 8HSGOs =8
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + F|WH=s3
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' okW'}@jD
FROM sysfiles C|ou7g4'p
WHERE name = @LogicalFileName \ItAc2,Fl
DROP TABLE DummyTrans y2C/DyuAY|
SET NOCOUNT OFF \g@jc OKU
8、说明:更改某个表 o{|
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exec sp_changeobjectowner 'tablename','dbo' MD+eLA7
9、存储更改全部表 PzLV}
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch %bnjK#o"Q
@OldOwner as NVARCHAR(128), ;u%4K$
@NewOwner as NVARCHAR(128) JAL"On#c#0
AS Ly/5" &HD
DECLARE @Name as NVARCHAR(128) eR8>5:V_
DECLARE @Owner as NVARCHAR(128) 'ka"0~:NS{
DECLARE @OwnerName as NVARCHAR(128) st CFLYox
DECLARE curObject CURSOR FOR yD ur9Qd6
select 'Name' = name, Nk>6:Ho{G
'Owner' = user_name(uid) ZOzyf/?.
from sysobjects w?c~be$
where user_name(uid)=@OldOwner 4_Rv}Yd
order by name k1WyV_3
OPEN curObject ]0p*EB=C*
FETCH NEXT FROM curObject INTO @Name, @Owner 23UXOY0BW
WHILE(@@FETCH_STATUS=0) -| t|w:&
BEGIN v-Uz,3
if @Owner=@OldOwner gkv,Om
begin e}"k8 ./
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 1]jUiX=T
exec sp_changeobjectowner @OwnerName, @NewOwner inx0W3d"T
end ~_SVQ7P
-- select @name,@NewOwner,@OldOwner "}UYsXg
FETCH NEXT FROM curObject INTO @Name, @Owner pvd9wKz
END tgm(tDL
close curObject Yf^/YLLS
deallocate curObject f]^ @z<FC
GO {S5D~A*a+
10、SQL SERVER中直接循环写入数据 n%P,"V
declare @i int Rv+p4RgA
set @i=1 [k6,!e[/uG
while @i<30 x6*.zo5e
begin 9\NP)Vm$^
insert into test (userid) values(@i) SVyJUd_
set @i=@i+1 #9hSo
end 3qH`zYgh
小记存储过程中经常用到的本周,本月,本年函数 3_k3U
Dateadd(wk,datediff(wk,0,getdate()),-1) xZ&S7G1