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。 />E
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一、基础 3:Nc`tM_
1、说明:创建数据库 )U|V |yem'
CREATE DATABASE database-name I`oJOLV
2、说明:删除数据库 aHC%:)ww:
drop database dbname \},H\kK+^
3、说明:备份sql server ;76+J)
--- 创建 备份数据的 device rZwSo]gp
USE master o5J6Xi0+
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' !i8)si_
--- 开始 备份 517"x@6Q
BACKUP DATABASE pubs TO testBack ShL!7y*rT{
4、说明:创建新表 vfn[&WN]
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) hN K wQ
根据已有的表创建新表: NsYEBT7f
A:create table tab_new like tab_old (使用旧表创建新表) [2xu`HT02
B:create table tab_new as select col1,col2... from tab_old definition only !X: TieyVu
5、说明:删除新表 .! <yTh
drop table tabname jMBMqQNU
6、说明:增加一个列 Y$XzZ>VW
Alter table tabname add column col type ;{0alhMZ
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 }%}$h2:
7、说明:添加主键: Alter table tabname add primary key(col) 6 8n ;#-X
说明:删除主键: Alter table tabname drop primary key(col) i 1w]j
8、说明:创建索引:create [unique] index idxname on tabname(col....) G*EF_N.G0
删除索引:drop index idxname u9Adu`
注:索引是不可更改的,想更改必须删除重新建。 @su<_m6'
9、说明:创建视图:create view viewname as select statement zjA#8;h~w
删除视图:drop view viewname } *)l
10、说明:几个简单的基本的sql语句 % S"z9@
选择:select * from table1 where 范围 DM v;\E~D
插入:insert into table1(field1,field2) values(value1,value2) H(K!{k
删除:delete from table1 where 范围 qF^P\cD
更新:update table1 set field1=value1 where 范围 `D=OEc
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! +C;;4s)
排序:select * from table1 order by field1,field2 [desc] \i[N";K
总数:select count as totalcount from table1 %pWJ2J@
求和:select sum(field1) as sumvalue from table1 =Bc{0p*
平均:select avg(field1) as avgvalue from table1 y`$qcEw
最大:select max(field1) as maxvalue from table1 7;@YR
最小:select min(field1) as minvalue from table1 IAkQR0fcN
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11、说明:几个高级查询运算词 |FT.x9e-
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A: UNION 运算符 h`! 4`eI
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 jqvw<+#
B: EXCEPT 运算符 -">Tvi4
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 c"knzB vy
C: INTERSECT 运算符 C$q-WoTM(
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。 gO*Gf2AG
注:使用运算词的几个查询结果行必须是一致的。 fA?Wf[`x
12、说明:使用外连接 @G#`uoD
A、left outer join: [7x;H
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。 i@P=*lLD
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+sB/l"
B:right outer join: RF6]_-
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。 N1g;e?T':
C:full outer join: \Qv:7;?
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。 hx%UZ <a
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二、提升 f]2gjQHM
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) sX>|Y3S\U
法一:select * into b from a where 1<>1 &{WEtaXaa
法二:select top 0 * into b from a h$~$a;2cR
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) z,C>Rh9Id
insert into b(a, b, c) select d,e,f from b; +LWgby4q
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) 4u|6^wu.I
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ;$!0pxL)s
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. |%X_<Cpk
4、说明:子查询(表名1:a 表名2:b) Lrx"Hn{
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) OB(~zUe.R
5、说明:显示文章、提交人和最后回复时间 zhRF>Y`
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b e6gj'GmY
6、说明:外连接查询(表名1:a 表名2:b) [A!=Hv_$
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'P[uB/
7、说明:在线视图查询(表名1:a ) bDw\;bnG
select * from (SELECT a,b,c FROM a) T where t.a > 1; m`XaY J
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 R*dXbI&,e
select * from table1 where time between time1 and time2 J{EK}'
select a,b,c, from table1 where a not between 数值1 and 数值2 I[ZWOi\-
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9、说明:in 的使用方法 -Vg0J6x
select * from table1 where a [not] in ('值1','值2','值4','值6') aQ 6T2bQ
10、说明:两张关联表,删除主表中已经在副表中没有的信息 kc2E4i
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) g2r8J0v
11、说明:四表联查问题: z"sv,W
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 ..... \=W t{
12、说明:日程安排提前五分钟提醒 Q6X}R,KA1
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 oFGgr2Re
13、说明:一条sql 语句搞定数据库分页 [z}$G: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 xdsF! Zb
14、说明:前10条记录 Zr\G=0`
select top 10 * form table1 where 范围 =PBJ+"DQs
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.) Me,AE^pgL'
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) =)6|lz^
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 9JC8OSjJ
(select a from tableA ) except (select a from tableB) except (select a from tableC) g'eJN
17、说明:随机取出10条数据 CBx5:}t
select top 10 * from tablename order by newid() ~]K<Vh`
18、说明:随机选择记录 N;,N6&veK/
select newid() f7]C1!]
19、说明:删除重复记录 ##NowO
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) l]e7
20、说明:列出数据库里所有的表名 CH h6Mnw
select name from sysobjects where type='U' Y2p~chx9
21、说明:列出表里的所有的 Cd'SPaR
select name from syscolumns where id=object_id('TableName') ;%i.@@:IQ
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。 ~hA;ji|I
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 1T7;=<g`
显示结果: Uefw
type vender pcs h@?BA<'S
电脑 A 1 6sRKbp|r7
电脑 A 1 3WdANR
光盘 B 2 9_S>G$9D
光盘 A 2 </d&bS
手机 B 3 p>]2o\["
手机 C 3 +4p gPv
23、说明:初始化表table1 oG;;='*
TRUNCATE TABLE table1 nR~L$Wu5_a
24、说明:选择从10到15的记录 _52BIrAO2
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc VlFDMw.4.+
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三、技巧 Q|}Pc>ae
1、1=1,1=2的使用,在SQL语句组合时用的较多 e6?h4}[+*
"where 1=1" 是表示选择全部 "where 1=2"全部不选, aTy&"
如: l0$
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if @strWhere !='' =p)Wxk
begin i'%:z]hp9
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere s],+]<qX
end %h%^i
else ~l@SGHx
begin vF K&.J
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' q<b;xx
end XoaB X2
我们可以直接写成 )nS;]7pB@
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere }_L@CpG
2、收缩数据库 V4!RUqK
--重建索引 h2Z Gh
DBCC REINDEX Rd5r~iT
DBCC INDEXDEFRAG a-,BBM 8|
--收缩数据和日志 >w?O?&Q$
DBCC SHRINKDB ht S5<+Y
DBCC SHRINKFILE Cj}1 )qWq
3、压缩数据库 H0s,tTK8
dbcc shrinkdatabase(dbname) Oav^BhUO
4、转移数据库给新用户以已存在用户权限 E#T-2^nD
exec sp_change_users_login 'update_one','newname','oldname' swnov[0
go HQ+:0"B
5、检查备份集 52>?l C
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' r
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6、修复数据库 ~OEP)c\k
ALTER DATABASE [dvbbs] SET SINGLE_USER X.g")Bt7
GO 0QDm3V0n
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 3M(:}c
GO k"V3FXC)
ALTER DATABASE [dvbbs] SET MULTI_USER kO\(6f2|x
GO c`y[V6q9
7、日志清除 Xt /muV
SET NOCOUNT ON _'dsEF
DECLARE @LogicalFileName sysname, }$;T.[ ~
@MaxMinutes INT, ^Yn{Vi2.
@NewSize INT v.,C"^W
USE tablename -- 要操作的数据库名 9QI\[lT&
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 Y'Jb@l`$-
@MaxMinutes = 10, -- Limit on time allowed to wrap log. A[!Fg0X0
@NewSize = 1 -- 你想设定的日志文件的大小(M) o_EXbS]C
-- Setup / initialize ,l`q
DECLARE @OriginalSize int z_<
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SELECT @OriginalSize = size nKh._bvfX
FROM sysfiles z8= Gc$w!
WHERE name = @LogicalFileName JMOQDo
SELECT 'Original Size of ' + db_name() + ' LOG is ' + *KFsO1j
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + VD+8j29
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 3`k1
FROM sysfiles ;vF8V`f
WHERE name = @LogicalFileName *n2Q_o
CREATE TABLE DummyTrans >3X!c"#l
(DummyColumn char (8000) not null) o
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DECLARE @Counter INT, RWXj)H)w
@StartTime DATETIME, L;5jhVy
@TruncLog VARCHAR(255) Hv<%_t_/
SELECT @StartTime = GETDATE(), JHc|.2Oe
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' WUdKj
DBCC SHRINKFILE (@LogicalFileName, @NewSize) Nd#t !=
EXEC (@TruncLog) .F?yt5{5No
-- Wrap the log if necessary. !Il>,q&F
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired <i~ (
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AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) s+tS4E?
AND (@OriginalSize * 8 /1024) > @NewSize Nj.(iBmr
BEGIN -- Outer loop. rr*",a"}m
SELECT @Counter = 0 @"kA&=0;|J
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ay'=M`uO_
BEGIN -- update rc*&K#? B
INSERT DummyTrans VALUES ('Fill Log') 6k42>e*p
DELETE DummyTrans zY\v|l<T
SELECT @Counter = @Counter + 1 Zo;@StN3}T
END ,^,Vq]$3
EXEC (@TruncLog) {j,bV6X
END +fAAkO*GP
SELECT 'Final Size of ' + db_name() + ' LOG is ' + W]_+3qvZ
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + TpZ) wC
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' *2 4P T7
FROM sysfiles aAwnkQ$
WHERE name = @LogicalFileName Vs8os+
DROP TABLE DummyTrans =@binTC4
SET NOCOUNT OFF 5 &-fX:/
8、说明:更改某个表 1F/`*z
exec sp_changeobjectowner 'tablename','dbo' }&rf'E9
9、存储更改全部表 _7]5Q
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch w^p
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@OldOwner as NVARCHAR(128), jLD=EJ
@NewOwner as NVARCHAR(128) 27t:-O
AS o,D>7|h
DECLARE @Name as NVARCHAR(128) >Bskw2
DECLARE @Owner as NVARCHAR(128) nrwb6wj
DECLARE @OwnerName as NVARCHAR(128) Puily9#
DECLARE curObject CURSOR FOR 4'Vuhqk
select 'Name' = name, > g8;x#
'Owner' = user_name(uid) `8xe2=Ub
from sysobjects -Qiay/tlu
where user_name(uid)=@OldOwner isDBNXV:
order by name &{x5 |$SD
OPEN curObject n9t8RcJS:
FETCH NEXT FROM curObject INTO @Name, @Owner @w,-T@nAW
WHILE(@@FETCH_STATUS=0) 'e7<&wm ia
BEGIN &UbNp8h
if @Owner=@OldOwner 3,oFT
begin
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set @OwnerName = @OldOwner + '.' + rtrim(@Name) S<88>|&n]
exec sp_changeobjectowner @OwnerName, @NewOwner ' "~|L>F%G
end H:,rNaz7D^
-- select @name,@NewOwner,@OldOwner G5"UhnOD'
FETCH NEXT FROM curObject INTO @Name, @Owner bH3-#mw5w
END rbO9NRg>
close curObject i?qS8h{
deallocate curObject , YTuZS
GO < I8hy$+6
10、SQL SERVER中直接循环写入数据 SL pd~ZC?
declare @i int >Ah [uM
set @i=1 ="d}:Jl
while @i<30 3)atqM)i
begin P9G c)$6{p
insert into test (userid) values(@i) yGZb
set @i=@i+1 eDX{}Dq(
end s$&:F4=?
小记存储过程中经常用到的本周,本月,本年函数 (t>BO`,
Dateadd(wk,datediff(wk,0,getdate()),-1) QC \8Zy
Dateadd(wk,datediff(wk,0,getdate()),6) db@i*Bf
Dateadd(mm,datediff(mm,0,getdate()),0) K> lA6i7?
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) c:>&Bg&,6T
Dateadd(yy,datediff(yy,0,getdate()),0) _j}|R(s*+V
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) -PBm@}*
上面的SQL代码只是一个时间段 <^
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Dateadd(wk,datediff(wk,0,getdate()),-1) (pREo/ T
Dateadd(wk,datediff(wk,0,getdate()),6) %%G2w63M
就是表示本周时间段. XBF#ILJ
下面的SQL的条件部分,就是查询时间段在本周范围内的: $FNj>1
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) CS:j->
而在存储过程中 U$# ?Lw
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) `rbTB3?
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ?`uY*+u