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。 GK8x<Aq%z
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一、基础 IPEJ7n49
1、说明:创建数据库 O\ph!?L
CREATE DATABASE database-name Hsvu&>[`S
2、说明:删除数据库 XR.Sm<A[
drop database dbname 026|u|R
3、说明:备份sql server J'4V_Kjg-
--- 创建 备份数据的 device e!.r- v9
USE master fd /?x^Z
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' xYl ScM_~
--- 开始 备份 v*VId
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BACKUP DATABASE pubs TO testBack /IyCvo
4、说明:创建新表 3_cZaru
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ra>jVE0`
根据已有的表创建新表: ?TEdGe\*
A:create table tab_new like tab_old (使用旧表创建新表) 8zWKKcf7t
B:create table tab_new as select col1,col2... from tab_old definition only GjGt'
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5、说明:删除新表 l>iE1`iL<
drop table tabname jI~GRk
6、说明:增加一个列 Sz3Tp5b
Alter table tabname add column col type EL+P,q/b
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。 kNDN<L
7、说明:添加主键: Alter table tabname add primary key(col) j%@wQVxq
说明:删除主键: Alter table tabname drop primary key(col) tG}cmK~%
8、说明:创建索引:create [unique] index idxname on tabname(col....) aH+n]J]
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删除索引:drop index idxname 0Er;l|
注:索引是不可更改的,想更改必须删除重新建。 CHo(:A.U>
9、说明:创建视图:create view viewname as select statement H6/C7
删除视图:drop view viewname b0ablVk
10、说明:几个简单的基本的sql语句 %3A~&
选择:select * from table1 where 范围 mb_~
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插入:insert into table1(field1,field2) values(value1,value2) `(6g87h
删除:delete from table1 where 范围 \Czuf
更新:update table1 set field1=value1 where 范围 Md(h-wYr
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! y`Km96Ui
排序:select * from table1 order by field1,field2 [desc] kjOPsz*0
总数:select count as totalcount from table1 p5PTuJ>q
求和:select sum(field1) as sumvalue from table1 pJ;4rrSK
平均:select avg(field1) as avgvalue from table1 |\iJ6m;a
最大:select max(field1) as maxvalue from table1 3,4m|Z2)
最小:select min(field1) as minvalue from table1 fx`oe
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11、说明:几个高级查询运算词 $(JB"%S8c
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A: UNION 运算符 (TQhO$,
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。 C#Y_La
B: EXCEPT 运算符 u~VvGLFf5,
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。 |uRZT3bGyj
C: INTERSECT 运算符 bi 8Qbo4
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。 9]^ CDL
注:使用运算词的几个查询结果行必须是一致的。 JC}oc M
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12、说明:使用外连接 Y9_OkcW)
A、left outer join: P]wCC`qi
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。 'vV|un(6
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 $`O%bsjX
B:right outer join: ^ua8Ya
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。 @}B,l.Tj
C:full outer join: lhRo+X#G
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。 w=MiJr#3^
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二、提升 wdzZ41y1
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ;;;{<GEQ
法一:select * into b from a where 1<>1 -D-]tL6w
法二:select top 0 * into b from a UxS@]YC
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 5^ +QTQ
insert into b(a, b, c) select d,e,f from b; 4(O;lVT}
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) s_`=ugue
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ->29Tns
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. sn6:\X<[
4、说明:子查询(表名1:a 表名2:b) A(dWAe,
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) lX*IEAc
5、说明:显示文章、提交人和最后回复时间 ,OilGTQ#
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b uBXl ltU
6、说明:外连接查询(表名1:a 表名2:b) pk5W!K
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c M);@XcS
7、说明:在线视图查询(表名1:a ) ;4]
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select * from (SELECT a,b,c FROM a) T where t.a > 1; k~+(X|!5w
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 nL]-]n;
select * from table1 where time between time1 and time2 <~}#Q,9
select a,b,c, from table1 where a not between 数值1 and 数值2 nm.~~h+8M
9、说明:in 的使用方法 ZN]LJ4|xu
select * from table1 where a [not] in ('值1','值2','值4','值6') Am&PH(}L
10、说明:两张关联表,删除主表中已经在副表中没有的信息 e6JT|>9A7
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) n0*a.
11、说明:四表联查问题: @M!WosRk
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 ..... c6"hk_
12、说明:日程安排提前五分钟提醒 Fs|aH-9\
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 1P1"xT
13、说明:一条sql 语句搞定数据库分页 )of?!>'S[
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 tbr1mw'G
14、说明:前10条记录 nC;2wQ6aO
select top 10 * form table1 where 范围 aO'lk
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.) JE$aYs<(TF
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 9=wt9` ?
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 2A^>>Q/,u
(select a from tableA ) except (select a from tableB) except (select a from tableC) \vR&-+8dk
17、说明:随机取出10条数据 '.8E_Jd0E
select top 10 * from tablename order by newid() !f^'-
18、说明:随机选择记录 AO"pm
select newid() eGi[LJ)np
19、说明:删除重复记录 gBZ1We u-'
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) RO10$1IW.2
20、说明:列出数据库里所有的表名 u_~*)w+mS@
select name from sysobjects where type='U' ("
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21、说明:列出表里的所有的 Oi~]~+2
select name from syscolumns where id=object_id('TableName') @C34^\aH+
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。 RV2s@<0p
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 vUa&9Y
显示结果: 5`?'}_[Yj
type vender pcs MsL*\)*s
电脑 A 1 aOr'OeG(=e
电脑 A 1 F7r!zKXZ
光盘 B 2 I8RPW:B;B
光盘 A 2 .2V`sg.!
手机 B 3 !qjIhZi
手机 C 3 as%ab[ fX
23、说明:初始化表table1 E"|LA[o
TRUNCATE TABLE table1 wh~g{(Xvq
24、说明:选择从10到15的记录 .7"]/9oB
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 6AW{qU6
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三、技巧 jZX2)# a!
1、1=1,1=2的使用,在SQL语句组合时用的较多 @TTB$
"where 1=1" 是表示选择全部 "where 1=2"全部不选, }%;o#!<N(@
如: NWt `X!
if @strWhere !='' (6*CORE
begin .*bu:FuDE
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere r- :u*
end 8LMO2Wyq
else O
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begin bZB7t`C5
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 0 kM4\En
end 9O.okU
我们可以直接写成 4%(\y"T
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere N5SePA\ ,?
2、收缩数据库 #EO@<>I
--重建索引 A=z+@b6
DBCC REINDEX #nv =x&g
DBCC INDEXDEFRAG ("7rjQjRz
--收缩数据和日志 P&s-U6
DBCC SHRINKDB >4.K>U?0FC
DBCC SHRINKFILE el;ey Ga
3、压缩数据库 0"vI6Lm
dbcc shrinkdatabase(dbname) %}nNwuJ
4、转移数据库给新用户以已存在用户权限 A=(<g";m
exec sp_change_users_login 'update_one','newname','oldname' 'fqX^v5n
go v|&Nh?r
5、检查备份集 hPP,D\#
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' @We im7r
6、修复数据库 4w\@D>@}H
ALTER DATABASE [dvbbs] SET SINGLE_USER /ehmy(zL
GO 5a PPq~%
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ~T{^7"q\
GO I)B+h8l72<
ALTER DATABASE [dvbbs] SET MULTI_USER K>tubLYh
GO "\x<Zg;
7、日志清除 !\DlX|
SET NOCOUNT ON |\lsTY&2
DECLARE @LogicalFileName sysname, #c?xJ&bh
@MaxMinutes INT, l.
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@NewSize INT *" ("^_x\
USE tablename -- 要操作的数据库名 j!It1B
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 'F)93SwU
@MaxMinutes = 10, -- Limit on time allowed to wrap log. h
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@NewSize = 1 -- 你想设定的日志文件的大小(M) /:YM{,]
-- Setup / initialize Fbpe`pS+V
DECLARE @OriginalSize int xejQ!MAB
SELECT @OriginalSize = size Y2j>@
FROM sysfiles R0l5"l*@+
WHERE name = @LogicalFileName 'K L"i
SELECT 'Original Size of ' + db_name() + ' LOG is ' + n I63Ns
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + (&W&1KT
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' -8r';zR
FROM sysfiles &7i o/d\/
WHERE name = @LogicalFileName s?:&#
CREATE TABLE DummyTrans 5-3.7CO$
(DummyColumn char (8000) not null) gyz#:z$p^
DECLARE @Counter INT, ~`uEZ
@StartTime DATETIME, R-~ZvVw7L
@TruncLog VARCHAR(255)
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SELECT @StartTime = GETDATE(), P0B`H7D
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' v/fo`]zP
DBCC SHRINKFILE (@LogicalFileName, @NewSize) TQ{rg2_T
EXEC (@TruncLog) k"kGQk4
-- Wrap the log if necessary. %|tDb
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired e6
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AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) !>,\KxnM
AND (@OriginalSize * 8 /1024) > @NewSize /f5*KRM
BEGIN -- Outer loop. Qcy
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SELECT @Counter = 0 LkUYh3
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) "}ms|
BEGIN -- update Q1A_hW2 x
INSERT DummyTrans VALUES ('Fill Log') Z4^O`yS9+
DELETE DummyTrans E=H>|FgS
SELECT @Counter = @Counter + 1 d'oh-dj %^
END p-6Y5$Y
EXEC (@TruncLog) 5a`f%
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END hnk,U:7}
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ji|+E`Nii
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + _6tir'z
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' o4%H/|Oq.
FROM sysfiles )}/ ycTs
WHERE name = @LogicalFileName ]tjQy1M
DROP TABLE DummyTrans u["3| `C5
SET NOCOUNT OFF %`M IGi#
8、说明:更改某个表 ,R-T( <r
exec sp_changeobjectowner 'tablename','dbo' 0gLl>tF[H
9、存储更改全部表
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CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch _uYidtxo=
@OldOwner as NVARCHAR(128), \4/zvlo]h
@NewOwner as NVARCHAR(128) OH(w3:;[8
AS 4
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DECLARE @Name as NVARCHAR(128) hLv~N}
DECLARE @Owner as NVARCHAR(128) SH009@l_8
DECLARE @OwnerName as NVARCHAR(128) F&Bh\C)]
DECLARE curObject CURSOR FOR r+0<A.''a
select 'Name' = name, ]#7{x
'Owner' = user_name(uid) QGR}`n2D
from sysobjects 0Z m^6T
where user_name(uid)=@OldOwner yobcAV`
order by name o4^|n1vN
OPEN curObject WRBCNra
FETCH NEXT FROM curObject INTO @Name, @Owner DV8b<)
WHILE(@@FETCH_STATUS=0) +2KYtyI
BEGIN Ao0p=@Y
if @Owner=@OldOwner M_OvIU(E
begin cbton<r~
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ?ufX3yia
exec sp_changeobjectowner @OwnerName, @NewOwner !Lu noC>B
end +nz6+{li\
-- select @name,@NewOwner,@OldOwner 61[ 8I},V
FETCH NEXT FROM curObject INTO @Name, @Owner +.EP_2f9
END dbE]&w`?d
close curObject K1gZ>FEY|N
deallocate curObject M2$.Yom[
GO P[G.LO
10、SQL SERVER中直接循环写入数据 Asy&X
declare @i int "CX@a"
set @i=1 |=o)|z2
while @i<30 L&I8lG
begin \[>Ob
insert into test (userid) values(@i) Un~8N
set @i=@i+1 Qf>$'C(7!a
end (2SmB`g
小记存储过程中经常用到的本周,本月,本年函数 _x2i=SFo*$
Dateadd(wk,datediff(wk,0,getdate()),-1) Mur)'
Dateadd(wk,datediff(wk,0,getdate()),6) o4zX
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Dateadd(mm,datediff(mm,0,getdate()),0) 9tMaOm
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ^%qe&Pe2
Dateadd(yy,datediff(yy,0,getdate()),0) TEzMFu+V
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 9sgyg3fv>5
上面的SQL代码只是一个时间段 pGsk[.
Dateadd(wk,datediff(wk,0,getdate()),-1) k6}M7&nY
Dateadd(wk,datediff(wk,0,getdate()),6) Fad.!%[
就是表示本周时间段. mRNA ,*
下面的SQL的条件部分,就是查询时间段在本周范围内的: mr6 ~8I
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) EZY <k#
而在存储过程中 xsO
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select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) FJ/c(K
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) -PG81F&K