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。 [
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一、基础 /yp/9r@T0
1、说明:创建数据库 ssT@<Tk^4
CREATE DATABASE database-name n.I2$._(b
2、说明:删除数据库 ?$16A+
drop database dbname EIPnm%{1
3、说明:备份sql server c"qPTjY
--- 创建 备份数据的 device w49{-Pp[
USE master /4-}k
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' k{{hZ/om
--- 开始 备份 p_9g|B0D
BACKUP DATABASE pubs TO testBack lZvS0JS
4、说明:创建新表 }+_9"YQ:
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) {( dP
根据已有的表创建新表: }\VX^{ K j
A:create table tab_new like tab_old (使用旧表创建新表) cafsMgrA
B:create table tab_new as select col1,col2... from tab_old definition only }U
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5、说明:删除新表 7O9n!aJ
drop table tabname ;b|
6、说明:增加一个列 '{CWanTPi
Alter table tabname add column col type B#:E?a;{
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 L&'l3|
7、说明:添加主键: Alter table tabname add primary key(col) L:i+}F;M)s
说明:删除主键: Alter table tabname drop primary key(col) }biCQ*{'
8、说明:创建索引:create [unique] index idxname on tabname(col....) t*s!0'Y
删除索引:drop index idxname ]\`w1'*
注:索引是不可更改的,想更改必须删除重新建。 19) !$Hl
9、说明:创建视图:create view viewname as select statement %}ixgs7*c0
删除视图:drop view viewname ^ `je
10、说明:几个简单的基本的sql语句 *k4+ioFnKE
选择:select * from table1 where 范围 L W?&a3e
插入:insert into table1(field1,field2) values(value1,value2) A9iQ{l
删除:delete from table1 where 范围 ([tG y
更新:update table1 set field1=value1 where 范围 ~hzEKvs
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! QheDF7'z
排序:select * from table1 order by field1,field2 [desc] A'`P2Am
总数:select count as totalcount from table1 X+%u(>>
求和:select sum(field1) as sumvalue from table1 s_v}=C^
平均:select avg(field1) as avgvalue from table1 @'Q%Jc(
最大:select max(field1) as maxvalue from table1 e lay
=%)
最小:select min(field1) as minvalue from table1 9ClF<5?M
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11、说明:几个高级查询运算词 `^zQ$au'u
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A: UNION 运算符 jP7w6sk
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UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 wM0E%6
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B: EXCEPT 运算符 Wkww&Y
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 GeVc\$K-
C: INTERSECT 运算符 @~hz_Nm@8
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 Q84t9b
注:使用运算词的几个查询结果行必须是一致的。 ;!:F#gahv
12、说明:使用外连接 )6g&v'dq
A、left outer join: "d2LyQy
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 l)H9J]
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c g/6nwa
B:right outer join: 1P \up
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 n-W?Z'H{r
C:full outer join: @T_O6TcY
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 -C=]n<ak
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二、提升 ?N(u4atC
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) l=,.iv=W
法一:select * into b from a where 1<>1 }Py<qXH
法二:select top 0 * into b from a _En]@xK3&
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) .1 Vu-@
insert into b(a, b, c) select d,e,f from b; OkkhP
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 6Z$b?A3zM
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 V.U|OQouT
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. rrYp'L
4、说明:子查询(表名1:a 表名2:b) Ty.drM
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) }\U0[x#q
5、说明:显示文章、提交人和最后回复时间 5qeT4|
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select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b ;*_I,|A:Xr
6、说明:外连接查询(表名1:a 表名2:b) }0vtc[!
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c wqf& i^_
7、说明:在线视图查询(表名1:a ) tG_-;03<`4
select * from (SELECT a,b,c FROM a) T where t.a > 1; FRc |D
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 y.
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select * from table1 where time between time1 and time2 z(#=tC|
select a,b,c, from table1 where a not between 数值1 and 数值2 [rc'/@L
9、说明:in 的使用方法 UJ
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select * from table1 where a [not] in ('值1','值2','值4','值6') 0:s8o@}
10、说明:两张关联表,删除主表中已经在副表中没有的信息 '8L(f w{k
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) :C>J-zY
11、说明:四表联查问题: o%$<LaQG5
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... s!NisF
12、说明:日程安排提前五分钟提醒 `I@)<d
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 {rs6"X^
13、说明:一条sql 语句搞定数据库分页 JE/l#Q!
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 )ynA:LXx
14、说明:前10条记录 2YaTT& J
select top 10 * form table1 where 范围 ~>4@;
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) t&8<k+m
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) G[vUOEU~O
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 a
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(select a from tableA ) except (select a from tableB) except (select a from tableC) zV6AuUIt
17、说明:随机取出10条数据 |3aS17yL>
select top 10 * from tablename order by newid() J6= w:c
18、说明:随机选择记录 8xc8L1;
select newid() Hxj'38Y
19、说明:删除重复记录 O\3r%=TF
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ,.J<.#D3J
20、说明:列出数据库里所有的表名 R%qX_m\0
select name from sysobjects where type='U' (R,NV3m?w
21、说明:列出表里的所有的 6vMDm0sv
select name from syscolumns where id=object_id('TableName') ,>:XE@xcp
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 (/To?`
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type wVlSjk
显示结果: fMgcK$
type vender pcs =%:JjgKc*t
电脑 A 1 t%0r"bTi
电脑 A 1 :v|r= #OI
光盘 B 2 ](]*]a4ss
光盘 A 2 ;L#LDk{Za
手机 B 3 u XaL
手机 C 3 3-4Nad
23、说明:初始化表table1 Wdei`u[
TRUNCATE TABLE table1 iH($rSE
24、说明:选择从10到15的记录 c1 gz#,
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc YK(XS"Kl
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三、技巧 Kc%tnVyGh:
1、1=1,1=2的使用,在SQL语句组合时用的较多 {vf+sf^^q
"where 1=1" 是表示选择全部 "where 1=2"全部不选, G~Sy&XJuq
如: ,?P8m"
if @strWhere !='' Lw!?T(SK
begin K<Yn_G
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere p_D
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end Y8x(#qp,
else @1/Q
begin $71i+h]_
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' a*pXrp@
end 0+$hkd n
我们可以直接写成 2&zn^\%"
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere xc:`}4
2、收缩数据库 =1V>Vd?8.
--重建索引 -wPuml!hZ|
DBCC REINDEX uzat."`d'
DBCC INDEXDEFRAG _|Y.!ZRYP
--收缩数据和日志 !7kAJG g
DBCC SHRINKDB <=B1"'\
DBCC SHRINKFILE IM l9\U
3、压缩数据库 7I @9v=xV
dbcc shrinkdatabase(dbname) AH"g^ gw~T
4、转移数据库给新用户以已存在用户权限 /1[}G!
exec sp_change_users_login 'update_one','newname','oldname' @5<]W+jk4
go e'}ePvN
5、检查备份集 D2hAlV)i(
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ~(w=U *
6、修复数据库 V{7lltu
ALTER DATABASE [dvbbs] SET SINGLE_USER _OyP>|L'
GO +9=@E
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 5`OK-
GO ;EE{~
ALTER DATABASE [dvbbs] SET MULTI_USER |SSfG~r
GO ]6?c8/M
7、日志清除 [R@q]S/
SET NOCOUNT ON =woqHTR
DECLARE @LogicalFileName sysname, ;]l{D}
@MaxMinutes INT, eG[umv.9b
@NewSize INT q?e16M
USE tablename -- 要操作的数据库名 'l0eo' K
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 LaEX kb*s
@MaxMinutes = 10, -- Limit on time allowed to wrap log. l^!0|/Vw
@NewSize = 1 -- 你想设定的日志文件的大小(M) 1FXzAc(c!
-- Setup / initialize XcJ'm{=
DECLARE @OriginalSize int ,6cbD
SELECT @OriginalSize = size -KJ}.q>upq
FROM sysfiles ` $QzTv
WHERE name = @LogicalFileName 3:02`;3
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 6T}
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CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 9.MGH2^L?
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' Y_|K,T6Zj@
FROM sysfiles c (_oK ?
WHERE name = @LogicalFileName os"[Iji
CREATE TABLE DummyTrans ?%8})^Dd>4
(DummyColumn char (8000) not null) Q(!}t"u
DECLARE @Counter INT, #J<`p
@StartTime DATETIME, |}]JWsuB
@TruncLog VARCHAR(255) g0;&/;"
SELECT @StartTime = GETDATE(), eNlF2M
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' q7)]cY_
DBCC SHRINKFILE (@LogicalFileName, @NewSize) cLN[o8ZU
EXEC (@TruncLog) Z!s>AgH9u
-- Wrap the log if necessary. goBKr: &]w
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired @+T{M:&l
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 2F*Dkv
AND (@OriginalSize * 8 /1024) > @NewSize >M8^Jgh
BEGIN -- Outer loop. 'JW_]z1
SELECT @Counter = 0 /64^5DjTh
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) toYg$IV
BEGIN -- update R4Gg|Bh
INSERT DummyTrans VALUES ('Fill Log') #h
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DELETE DummyTrans K{r1&O>W
SELECT @Counter = @Counter + 1 dwf #~7h_
END FS]+s>
EXEC (@TruncLog) MK!]y8+Z
END Ztpm_P6
SELECT 'Final Size of ' + db_name() + ' LOG is ' + c9cphZ(z
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 5@r_<J<>
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' yv#c=v|
FROM sysfiles 8g2-8pa{
WHERE name = @LogicalFileName *Wuctu^9
DROP TABLE DummyTrans ]y)R C-N
SET NOCOUNT OFF ]<o.aMdV
8、说明:更改某个表 (x@i,Ba@
exec sp_changeobjectowner 'tablename','dbo' QB.*R? A
9、存储更改全部表 c5mhl;+'
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch M~g~LhsF
@OldOwner as NVARCHAR(128), -Uhl9
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@NewOwner as NVARCHAR(128) q!9v}R3(
AS U d=gdsL
DECLARE @Name as NVARCHAR(128) 3 DO$^JJ.
DECLARE @Owner as NVARCHAR(128) 1>*UbV<R;u
DECLARE @OwnerName as NVARCHAR(128) 0[$Mo3c+'
DECLARE curObject CURSOR FOR bTo@gJkn
select 'Name' = name, 0D]Yz`n3
'Owner' = user_name(uid) !Sy'Z6%f
from sysobjects '#An+;x{
where user_name(uid)=@OldOwner ;&t1FH#=
order by name |<+|Du1
OPEN curObject L]L~TA<D9i
FETCH NEXT FROM curObject INTO @Name, @Owner @e?[oojrM
WHILE(@@FETCH_STATUS=0) u`H@Q&(^wa
BEGIN {eD>E(Y@z1
if @Owner=@OldOwner O(
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begin /PB3^d>Q2
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 61Iy{-/ZV
exec sp_changeobjectowner @OwnerName, @NewOwner >I8hFtAM
end 65`'Upu
-- select @name,@NewOwner,@OldOwner .KwuhmR
FETCH NEXT FROM curObject INTO @Name, @Owner a@a1TpLQ
END f)s_e
close curObject {p lmFV
deallocate curObject e2=,n6N]c
GO - R8!"~o
10、SQL SERVER中直接循环写入数据 wor'=byh\
declare @i int KiRt'
set @i=1 @)juP- o%
while @i<30 SUnmp
begin
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insert into test (userid) values(@i) Cak/#1
set @i=@i+1 "<n"A7e
end /x8C70W^
小记存储过程中经常用到的本周,本月,本年函数 :]z-Rz
Dateadd(wk,datediff(wk,0,getdate()),-1) M]/wei"X
Dateadd(wk,datediff(wk,0,getdate()),6) .V )2Tz
Dateadd(mm,datediff(mm,0,getdate()),0) G4J6
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) OTtanJ?
Dateadd(yy,datediff(yy,0,getdate()),0) ZX5A%`<M
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) [,szx1
上面的SQL代码只是一个时间段 :7PSZc:xE
Dateadd(wk,datediff(wk,0,getdate()),-1) XL&eJ
Dateadd(wk,datediff(wk,0,getdate()),6) ka9v2tE\
就是表示本周时间段. U=cWvr65
下面的SQL的条件部分,就是查询时间段在本周范围内的: t=pkYq5t8
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) '/qe#S
而在存储过程中 U%PMV?L{
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) \z2hXT@D
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) u b>K^