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。 R6h(mPYA
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一、基础 "7JO~T+v
1、说明:创建数据库 S@z$,}Yc`<
CREATE DATABASE database-name d\3L.5]X
2、说明:删除数据库 xQ* U9Wt;T
drop database dbname )T(xQ2&r4
3、说明:备份sql server Jv1.Yz
--- 创建 备份数据的 device x!{5.#
USE master YCj"^RC^
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' ?2
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--- 开始 备份 Gz+Bk5#{
BACKUP DATABASE pubs TO testBack d@b"tb}R
4、说明:创建新表 \Bw9%P~ G
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) f%an<>j^w
根据已有的表创建新表: G=jdb@V/?
A:create table tab_new like tab_old (使用旧表创建新表) WT;=K0W6&
B:create table tab_new as select col1,col2... from tab_old definition only Qa5<go{
5、说明:删除新表 9 @!Og(l
drop table tabname LU?X|{z
6、说明:增加一个列 KY!
Alter table tabname add column col type ]V6<h Psi
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 Ib*l{cxN
7、说明:添加主键: Alter table tabname add primary key(col) s!9.o_k
说明:删除主键: Alter table tabname drop primary key(col) 5MQD:K2
8、说明:创建索引:create [unique] index idxname on tabname(col....) !\}Dxt
删除索引:drop index idxname ]~U4;
注:索引是不可更改的,想更改必须删除重新建。 SWz+.W{KQ"
9、说明:创建视图:create view viewname as select statement e/r41
删除视图:drop view viewname UkG|5P`
10、说明:几个简单的基本的sql语句 bVQLj}%
选择:select * from table1 where 范围 q+19EJ(
插入:insert into table1(field1,field2) values(value1,value2) [~W"$sT
删除:delete from table1 where 范围 Zuo7MR
更新:update table1 set field1=value1 where 范围 {<\nl#}5S
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! R^1sbmwk
排序:select * from table1 order by field1,field2 [desc] y{uRh>l
总数:select count as totalcount from table1 Z WL/ AC
求和:select sum(field1) as sumvalue from table1 6ALf`:
平均:select avg(field1) as avgvalue from table1 lV?rC z
最大:select max(field1) as maxvalue from table1 )xiic3F
最小:select min(field1) as minvalue from table1 H\Y.l,^
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11、说明:几个高级查询运算词 ~Hd{+0
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A: UNION 运算符 u&I?LZ-=,
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。 TKx.`Cf
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B: EXCEPT 运算符 U-QK
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。 O/e5LA
C: INTERSECT 运算符 Gx|$A+U
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 Cl7IP<.
注:使用运算词的几个查询结果行必须是一致的。 1tDd4r?Y
12、说明:使用外连接 m>x.4aO1
A、left outer join: Op" \i
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 54_CewL1P]
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c =W.b7 6_
B:right outer join: nC$f0r"z
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。 xlp^XT6#
C:full outer join: ]!d #2(
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。 MOP/ q4j[
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二、提升 _k\*4K8L
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) IiHl"2+/
法一:select * into b from a where 1<>1 beRpA;
法二:select top 0 * into b from a B[F x2r`0
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) R^iF^IB
insert into b(a, b, c) select d,e,f from b; M9.jJf
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) ^o,P>u!9
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 Vk5}d[[l
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. f$Nz).(
4、说明:子查询(表名1:a 表名2:b) `J|bGf#
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) |#D3~au
5、说明:显示文章、提交人和最后回复时间 Dkayk
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b VE+Q Y9(
6、说明:外连接查询(表名1:a 表名2:b) :XxsD D
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c u>
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7、说明:在线视图查询(表名1:a ) +7U$qEG
select * from (SELECT a,b,c FROM a) T where t.a > 1; Yz us=
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 ZN~:^,PO/
select * from table1 where time between time1 and time2 "^fcXV9Wp
select a,b,c, from table1 where a not between 数值1 and 数值2 p[4KN(PyK
9、说明:in 的使用方法 \EuMzb"G9p
select * from table1 where a [not] in ('值1','值2','值4','值6') w=
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10、说明:两张关联表,删除主表中已经在副表中没有的信息 6%sX<)n%]
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) -%E+Yl{v
11、说明:四表联查问题: y))d[1E
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 ..... 0UB)FK,9
12、说明:日程安排提前五分钟提醒 %"r3{Hs
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 (TM1(<j
13、说明:一条sql 语句搞定数据库分页
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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 &W `."
14、说明:前10条记录 !f2f
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select top 10 * form table1 where 范围 wS-D"\4/
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=|sy-N{2
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) *IG} /O.VT
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 X!ZUR^
(select a from tableA ) except (select a from tableB) except (select a from tableC) qa)X\0
17、说明:随机取出10条数据 )cJ9YKKy
select top 10 * from tablename order by newid() *v
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18、说明:随机选择记录 u27K
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select newid() +)k%jIi!
19、说明:删除重复记录 =e=sK'NvD
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ]dHU
20、说明:列出数据库里所有的表名 .t*MGUg
select name from sysobjects where type='U' FloCR=^H
21、说明:列出表里的所有的 8iaP(*J
select name from syscolumns where id=object_id('TableName') rz+)z:u
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。 .aV#W@iyK
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 Eyv%"+>
显示结果: xok8
type vender pcs Hphvsre<
电脑 A 1 0"o%=i;
电脑 A 1 M>nplHq
光盘 B 2 tGDsZ;3Yr
光盘 A 2 S+
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手机 B 3 )ZC0/>R
手机 C 3 .;&c<c|
23、说明:初始化表table1 FpN >T
TRUNCATE TABLE table1 ;|*o^9q
24、说明:选择从10到15的记录 F`IV9qv
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc }K1v=k
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三、技巧 hg[ob+"
1、1=1,1=2的使用,在SQL语句组合时用的较多 o9&1Ct
"where 1=1" 是表示选择全部 "where 1=2"全部不选, hC2 @Gq
如: ! eXDN
if @strWhere !='' P>n}\"z4
begin C +S
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere Teh
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end -XBD WV
else i,|2F9YH
begin 8 SFw|
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' ;}"!|
end vncLB&@7
我们可以直接写成 l&}3M
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere CzDJbvv]
2、收缩数据库 NrA?^F
--重建索引 zV {_dO
DBCC REINDEX 'qel3Fs"
DBCC INDEXDEFRAG )RV.N}NU
--收缩数据和日志 <*k]Aa3y
DBCC SHRINKDB uU_lC5A|
DBCC SHRINKFILE UP]X,H~stU
3、压缩数据库 6+`+$s0
dbcc shrinkdatabase(dbname) Zpc R
4、转移数据库给新用户以已存在用户权限 whFaL}2C
exec sp_change_users_login 'update_one','newname','oldname' 12r]"?@|s
go jyB^a;-
5、检查备份集 1 ? be
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' sg0HYb%_E
6、修复数据库 OwRH
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ALTER DATABASE [dvbbs] SET SINGLE_USER 7HfA{.|m
GO ip.aM#
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ${ fJ]
GO Tk1U
ALTER DATABASE [dvbbs] SET MULTI_USER 'PiQ|Nnb|
GO bDK%vx!_
7、日志清除 .YOC|\
SET NOCOUNT ON fP 4
DECLARE @LogicalFileName sysname, J;@g#h?
@MaxMinutes INT, wP:ab
@NewSize INT ,F^Rz.
USE tablename -- 要操作的数据库名 'KL!)}B$h
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 vu7F>{D
@MaxMinutes = 10, -- Limit on time allowed to wrap log. .$&_fUY
@NewSize = 1 -- 你想设定的日志文件的大小(M) )/uu~9SFd
-- Setup / initialize o}QtKf)W
DECLARE @OriginalSize int U4PnQ
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SELECT @OriginalSize = size wX?<o
FROM sysfiles &\K p_ AR
WHERE name = @LogicalFileName QxUsdF?p
SELECT 'Original Size of ' + db_name() + ' LOG is ' + SA3!a.*c
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + W<']Q_su
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' [@K#BFA
FROM sysfiles leY fF
WHERE name = @LogicalFileName ";vP77|m7R
CREATE TABLE DummyTrans U42B(ow
(DummyColumn char (8000) not null) ?
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DECLARE @Counter INT, -bJC+Yn
@StartTime DATETIME, DX|yL!4[
@TruncLog VARCHAR(255) d^-sxl3}
SELECT @StartTime = GETDATE(), Q--Hf$D]H
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' iH&BhbRu_
DBCC SHRINKFILE (@LogicalFileName, @NewSize) U`*L` PM
EXEC (@TruncLog) vfnVN@ 5
-- Wrap the log if necessary. ..u2IdEu
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired gFBMARxi
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 7Qoy~=E
AND (@OriginalSize * 8 /1024) > @NewSize #21t8
BEGIN -- Outer loop. 3/d`s0O
SELECT @Counter = 0 $K-od3h4=
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) 'UW]~
BEGIN -- update g+ZQ6Hz
INSERT DummyTrans VALUES ('Fill Log') 4\Nt"#U)g
DELETE DummyTrans Cx,)$!1
SELECT @Counter = @Counter + 1 dJ/(u&N
END #}y(D{z c
EXEC (@TruncLog) P/9iB/
END )TH~Tq:
SELECT 'Final Size of ' + db_name() + ' LOG is ' + h
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CONVERT(VARCHAR(30),size) + ' 8K pages or ' + )wFr%wNe
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' "V7
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FROM sysfiles s01W_P .@R
WHERE name = @LogicalFileName T~Z7kc'
DROP TABLE DummyTrans U`25bb1Wj
SET NOCOUNT OFF 6B pm+}
8、说明:更改某个表 XMJ EIG
exec sp_changeobjectowner 'tablename','dbo' sD_"
9、存储更改全部表 .PAR
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch 4I %/}+Q
@OldOwner as NVARCHAR(128), I[td:9+hK@
@NewOwner as NVARCHAR(128) 335\0~;3
AS ]Sl]G6#Iwv
DECLARE @Name as NVARCHAR(128) *Y!c6eA
DECLARE @Owner as NVARCHAR(128) 9bE/7v
DECLARE @OwnerName as NVARCHAR(128) zG%ZDH^82_
DECLARE curObject CURSOR FOR 'OERW|BO
select 'Name' = name, Z3jtq-y
'Owner' = user_name(uid) (K"8kQLY
from sysobjects =5zx]N1r
where user_name(uid)=@OldOwner R MrrLT
order by name ,sn/FT^; q
OPEN curObject +[2X@J
FETCH NEXT FROM curObject INTO @Name, @Owner OvFWX%uY
WHILE(@@FETCH_STATUS=0) hp:8e@
BEGIN |izf|*e
if @Owner=@OldOwner LEM^8G]O
begin 0nX.%2p#Je
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ;?-`n4B&
exec sp_changeobjectowner @OwnerName, @NewOwner VOmWRy"L
end JE[+
-- select @name,@NewOwner,@OldOwner 1Vden.H*CI
FETCH NEXT FROM curObject INTO @Name, @Owner ]n/fB|t E
END l>H G|ol
close curObject 4t Z. T9d
deallocate curObject Wd0$t
GO vWM'}(
10、SQL SERVER中直接循环写入数据 [+j39d.Q
declare @i int #c2InwZV
set @i=1 s3.,
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while @i<30 L.]mC !
begin
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insert into test (userid) values(@i) |ULwUi-r
set @i=@i+1 HDTdOG)
end g;M\4o
小记存储过程中经常用到的本周,本月,本年函数 *`(/wE2v]
Dateadd(wk,datediff(wk,0,getdate()),-1) =z]8;<=pL
Dateadd(wk,datediff(wk,0,getdate()),6) JW`Kh*,~<
Dateadd(mm,datediff(mm,0,getdate()),0) 4
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Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ]0g%)f uMf
Dateadd(yy,datediff(yy,0,getdate()),0) I{V1Le4?
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) %s#`i$|z*n
上面的SQL代码只是一个时间段 >Za66<:
Dateadd(wk,datediff(wk,0,getdate()),-1) 8G SO] R
Dateadd(wk,datediff(wk,0,getdate()),6) HJ\CGYmyz
就是表示本周时间段. 2k^dxk~$V;
下面的SQL的条件部分,就是查询时间段在本周范围内的: qtv>`:neB
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) FyZ iiH4|
而在存储过程中 zF
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select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) j5cc"s
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) _`Abz2s