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。 s(J,TS#I]
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一、基础 CeoK@y=o
1、说明:创建数据库 "d>{hP
CREATE DATABASE database-name r}MXXn,f
2、说明:删除数据库 ` ZXX[&C
drop database dbname (Kd;l&8
3、说明:备份sql server &F*s.gL
--- 创建 备份数据的 device B@` 87
USE master R4u=.
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 0#KDvCBJ
--- 开始 备份 J5}-5sV^
BACKUP DATABASE pubs TO testBack pj G6v(zK
4、说明:创建新表 z_~f/
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) &i4*tE3],
根据已有的表创建新表: Gvw4ot/
A:create table tab_new like tab_old (使用旧表创建新表) ~mx me6"v
B:create table tab_new as select col1,col2... from tab_old definition only 7OG=LF*V-
5、说明:删除新表 aR ao\Wp|
drop table tabname p#)u2^
6、说明:增加一个列 V|ax(tHv
Alter table tabname add column col type 2cr~/,YY
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。 ^[Cpu_]D
7、说明:添加主键: Alter table tabname add primary key(col) R_:47.qq
说明:删除主键: Alter table tabname drop primary key(col) a33}CVG-e3
8、说明:创建索引:create [unique] index idxname on tabname(col....) ',?v7&
删除索引:drop index idxname kXA
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注:索引是不可更改的,想更改必须删除重新建。 aErms-~
9、说明:创建视图:create view viewname as select statement 4<)%Esyb
删除视图:drop view viewname b"t95qlL
10、说明:几个简单的基本的sql语句 iXK.QktHw
选择:select * from table1 where 范围 ilEWxr;,
插入:insert into table1(field1,field2) values(value1,value2) 3:7J@>
删除:delete from table1 where 范围 -z./6dQ
更新:update table1 set field1=value1 where 范围 o {Sc
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! \:]Clvc
排序:select * from table1 order by field1,field2 [desc] VG^*?62
总数:select count as totalcount from table1 q3adhY9|)0
求和:select sum(field1) as sumvalue from table1 ?Ko)AP
平均:select avg(field1) as avgvalue from table1 :t-a;Q;
最大:select max(field1) as maxvalue from table1 #ok1qT9_
最小:select min(field1) as minvalue from table1 A&rk5y;
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11、说明:几个高级查询运算词 at]=SA
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A: UNION 运算符 I?LJXo \O
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。 sx IvL7jl
B: EXCEPT 运算符 j+"i$ln+s
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。 ^EWkJW,Yc
C: INTERSECT 运算符 :#1{c^i%3
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。 z$$ E7i
注:使用运算词的几个查询结果行必须是一致的。 >Lx,<sE
12、说明:使用外连接 ~+}w>jIm{|
A、left outer join: VliX'.-
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。 0B#9CxU%
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 Y
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B:right outer join: 2jV.\C k
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。 losm<
C:full outer join: [ Hw
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。 rXc-V},az8
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二、提升 ~A2{$C
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) v=e`e68U~
法一:select * into b from a where 1<>1 `&2~\o/
法二:select top 0 * into b from a bD*V$w*P
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) e\%+~GUTC=
insert into b(a, b, c) select d,e,f from b; +?Vj}p;
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) q&OF?z7H
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 u+%Ca,6
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. /~[+'
4、说明:子查询(表名1:a 表名2:b) $mOVo'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) 'QW/TJ=7r
5、说明:显示文章、提交人和最后回复时间 6x|"1
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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 'RK.w^
6、说明:外连接查询(表名1:a 表名2:b) XG FjqZr`
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c JoeU J3N
7、说明:在线视图查询(表名1:a ) ? 3
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select * from (SELECT a,b,c FROM a) T where t.a > 1; f.8Jp<S2K
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 )Be?axI
select * from table1 where time between time1 and time2 b5K6F:D22
select a,b,c, from table1 where a not between 数值1 and 数值2 Agt6G\n
9、说明:in 的使用方法 TP7'tb
select * from table1 where a [not] in ('值1','值2','值4','值6') 6 /_] |4t
10、说明:两张关联表,删除主表中已经在副表中没有的信息 IX@g].)C
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) "~- H]9
11、说明:四表联查问题: QP/%+[E.
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 ..... /orpQUHA
12、说明:日程安排提前五分钟提醒 +c;/hM<IX.
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 ^*JpdmVhu
13、说明:一条sql 语句搞定数据库分页 n${,r
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 -5;Kyio
14、说明:前10条记录 !lxs1!:
select top 10 * form table1 where 范围
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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.) -}avH
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) .>?h
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 k |}&
(select a from tableA ) except (select a from tableB) except (select a from tableC) x?s5vxAKf
17、说明:随机取出10条数据 xuBXOr4"P
select top 10 * from tablename order by newid() >Y,3EI\
18、说明:随机选择记录 ,Vb;2
select newid() GZJIIP#
19、说明:删除重复记录 l{q$[/J~)
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) Z9Prw/8P
20、说明:列出数据库里所有的表名 K5l#dl_T
select name from sysobjects where type='U' [O~'\Q
21、说明:列出表里的所有的 s}"5uDfn1F
select name from syscolumns where id=object_id('TableName') T}')QC&wQ
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。 OSP#FjH
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 /8m2oL\<
显示结果:
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type vender pcs hLF+_{\C|
电脑 A 1 0zH^yx:ma
电脑 A 1 !;Hi9,<#7g
光盘 B 2 &"X6s%ZH|
光盘 A 2 fzcPi9+
手机 B 3 r*$$82s
手机 C 3 V.<$c1#=$
23、说明:初始化表table1 P(iZGOKUs=
TRUNCATE TABLE table1 CbPCj.MH
24、说明:选择从10到15的记录 ~9#x/EG/
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 5gP<+S#>T
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三、技巧 w\(LG_n|
1、1=1,1=2的使用,在SQL语句组合时用的较多 V[E7mhqy
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 6 0C;J!D
如: :CH*~o
if @strWhere !='' \1`L-lz
begin e|Ip7`
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere "F_o%!l
end 6@0
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else 1X-Ku GaD
begin aJh=4j~.
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' e<_yr>9g"
end [s1Hd~$
我们可以直接写成 D@]gc&JN[
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere VyRU_<xP
2、收缩数据库 ZHPsGHA
--重建索引 HbQvu@
DBCC REINDEX #Bo/1G=
DBCC INDEXDEFRAG lo }[o0X
--收缩数据和日志 @3D8TPH
DBCC SHRINKDB e[`E-br^
DBCC SHRINKFILE &uLxAw
3、压缩数据库 iC U[X&
dbcc shrinkdatabase(dbname) wLa^pI4p ^
4、转移数据库给新用户以已存在用户权限 bXN-q!
exec sp_change_users_login 'update_one','newname','oldname' &5*)r@+
go TF\<`}akX
5、检查备份集 sOyWsXd+R'
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 5fh@nR
6、修复数据库 Z=;+)
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ALTER DATABASE [dvbbs] SET SINGLE_USER |.bp
GO TmN}TMhZ
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK IKJ~sw~AQ
GO O5"o/Y~m
ALTER DATABASE [dvbbs] SET MULTI_USER eiLtZQ
GO WA);Z=
7、日志清除 hl4@Y#n
SET NOCOUNT ON OL+!,Y
DECLARE @LogicalFileName sysname, 6~ g:"}
@MaxMinutes INT, 7ko7)"N
@NewSize INT *%0f^~!G<p
USE tablename -- 要操作的数据库名 A<6V$e$:2
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 H>AzxhX[n
@MaxMinutes = 10, -- Limit on time allowed to wrap log. kvU0$1
@NewSize = 1 -- 你想设定的日志文件的大小(M) ?$O5w*
-- Setup / initialize
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DECLARE @OriginalSize int o]NL_SM_
SELECT @OriginalSize = size +mBJvrI
FROM sysfiles JOj\#!\>k0
WHERE name = @LogicalFileName vFfvvRda4x
SELECT 'Original Size of ' + db_name() + ' LOG is ' + Z=: oIAe
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + JCIm*6~
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' -Q@jL{Ue
FROM sysfiles
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WHERE name = @LogicalFileName //--r5Q
CREATE TABLE DummyTrans ;qI5GQ {
(DummyColumn char (8000) not null) l+'1>T.I
DECLARE @Counter INT, #vO3*-hs
@StartTime DATETIME, o3H+.u$
@TruncLog VARCHAR(255) Xco$
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SELECT @StartTime = GETDATE(), qa ![oMKc
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' =N,KVMxw
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ujcS>XN,1
EXEC (@TruncLog) `92 D]^g
-- Wrap the log if necessary. c$f|a$$b
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ixJUq o
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) lY}mrb
AND (@OriginalSize * 8 /1024) > @NewSize ;F&wGe
BEGIN -- Outer loop. ^H+j;K{5,
SELECT @Counter = 0 @LY 5]og
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ~A0E4UJgq
BEGIN -- update O$
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INSERT DummyTrans VALUES ('Fill Log') ;(w=}s%]+
DELETE DummyTrans 6'C!Au
SELECT @Counter = @Counter + 1 ";~}"Yz?[
END ]\nG1+ta
EXEC (@TruncLog) {nQ}t
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END 1A23G$D
SELECT 'Final Size of ' + db_name() + ' LOG is ' + V mQ7M4j*
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + z(<
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CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' f{e*R#+&
FROM sysfiles PF .sM(
WHERE name = @LogicalFileName ~H0~5v F
DROP TABLE DummyTrans #e%.z+7I
SET NOCOUNT OFF aMTY{
8、说明:更改某个表 ]P0DPea
exec sp_changeobjectowner 'tablename','dbo' <.3@-z>w2,
9、存储更改全部表 tC+9W1o
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch gB3&AQ
@OldOwner as NVARCHAR(128), -<#n7b
@NewOwner as NVARCHAR(128) i7~oZ)w
AS ej,MmLu~^
DECLARE @Name as NVARCHAR(128) Y=G *[G#
DECLARE @Owner as NVARCHAR(128) }wR)p
DECLARE @OwnerName as NVARCHAR(128) ZLvw]N&R
DECLARE curObject CURSOR FOR #f|-l$a)3a
select 'Name' = name, 1elx~5v1.=
'Owner' = user_name(uid) y_"GMw
from sysobjects yh_s(>sh
where user_name(uid)=@OldOwner I#l9
order by name Tu_dkif'
OPEN curObject OxF\Hm)(
FETCH NEXT FROM curObject INTO @Name, @Owner pb%#`2"
WHILE(@@FETCH_STATUS=0) 3Gn2@`GC
BEGIN s)=L6t^a6
if @Owner=@OldOwner whKr3)
begin >/n5=RWh
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 5*buRYck0
exec sp_changeobjectowner @OwnerName, @NewOwner [v-?MS
end 17D167\X
-- select @name,@NewOwner,@OldOwner }sy3Mrb
FETCH NEXT FROM curObject INTO @Name, @Owner LWbWj ^
END :yT~.AK}>1
close curObject gb(\c:yg1R
deallocate curObject v03~=(
GO v )7d
10、SQL SERVER中直接循环写入数据
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declare @i int qe(X5?#;
set @i=1 `j>qOT
while @i<30 P[P!WLr""
begin nE-=7S L
insert into test (userid) values(@i) %o4d43uZ
set @i=@i+1 Tf@t.4\
end 4v2(YJ%u
小记存储过程中经常用到的本周,本月,本年函数 ( kp}mSw
Dateadd(wk,datediff(wk,0,getdate()),-1) ZJ=C[s!wu
Dateadd(wk,datediff(wk,0,getdate()),6) EZP2Bb5g
Dateadd(mm,datediff(mm,0,getdate()),0) n+GC L+Mo
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) (%0X\zvu/
Dateadd(yy,datediff(yy,0,getdate()),0) %n}.E304
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) oU~V0{7g
上面的SQL代码只是一个时间段 !+)$;`
Dateadd(wk,datediff(wk,0,getdate()),-1) L&3=5Bf9
Dateadd(wk,datediff(wk,0,getdate()),6) Tjs-+$P+
就是表示本周时间段. uFdSD
下面的SQL的条件部分,就是查询时间段在本周范围内的: iI&SI#;
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Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) =As'vt
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而在存储过程中 5!nZvv
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) YSrFHVq
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ObM5v rEk|