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。 bhbTloCR
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一、基础 0E,QOF{o
1、说明:创建数据库 fR+{gazk
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CREATE DATABASE database-name l?V#;
2、说明:删除数据库 A"s?;hv\fS
drop database dbname j {2 0
3、说明:备份sql server Dv`"3
--- 创建 备份数据的 device 3^-R_
USE master ~gOZ\jm}
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' HY?#r]Ryt
--- 开始 备份 ocMTTVo
BACKUP DATABASE pubs TO testBack v0=v1G*rvJ
4、说明:创建新表 c#1kg@q@
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) (!J;g|58
根据已有的表创建新表: ^8]7
A:create table tab_new like tab_old (使用旧表创建新表) :F#^Q%-IS
B:create table tab_new as select col1,col2... from tab_old definition only 7#oq|5
5、说明:删除新表 #h
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drop table tabname \.p;
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6、说明:增加一个列 E?bv<L,"
Alter table tabname add column col type oSf`F1;)HQ
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。 |:4?K*w",
7、说明:添加主键: Alter table tabname add primary key(col) ],~[ ^0
说明:删除主键: Alter table tabname drop primary key(col) -1NR]#P'
8、说明:创建索引:create [unique] index idxname on tabname(col....) @g+v2(f2v
删除索引:drop index idxname iQT0%WaHl
注:索引是不可更改的,想更改必须删除重新建。 }~ N\A
9、说明:创建视图:create view viewname as select statement Li0+%ijM
删除视图:drop view viewname i gjn9p&_
10、说明:几个简单的基本的sql语句 5K682+^5
选择:select * from table1 where 范围 @]8flb
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插入:insert into table1(field1,field2) values(value1,value2) BA@M>j6d
删除:delete from table1 where 范围 *:"60fkoU
更新:update table1 set field1=value1 where 范围 MLM/!N 7
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! $>uUn3hSx\
排序:select * from table1 order by field1,field2 [desc] 4K dYiuz0`
总数:select count as totalcount from table1 !$ii*}
求和:select sum(field1) as sumvalue from table1 =h
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平均:select avg(field1) as avgvalue from table1 }Qe(6'l_
最大:select max(field1) as maxvalue from table1 K ;]dZ8
最小:select min(field1) as minvalue from table1 + @|u8+
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11、说明:几个高级查询运算词
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A: UNION 运算符 Kb;Pd!Q
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。 wgolgof
B: EXCEPT 运算符 92.Rjz;=9?
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。 br
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C: INTERSECT 运算符 d)D!np=
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。 &m[}%e%~0
注:使用运算词的几个查询结果行必须是一致的。 !g}@xwWax
12、说明:使用外连接 -aE,KQ
A、left outer join: F9r/
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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。 "rEfhzmyF
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 jq8TfJ|
B:right outer join: 8fBhX,1
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。 #f_'&m
C:full outer join: .d$Q5Qae
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 y;4g>ma0
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二、提升 ]q[(z
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) gW4fwE^
法一:select * into b from a where 1<>1 l,(:~KH|
法二:select top 0 * into b from a 4}cxSl]jf!
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) E4Ez)IaKyi
insert into b(a, b, c) select d,e,f from b; HkhZB^_V
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) LjW32>B
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 +|8.ymvm
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. ZG#:3d*)
4、说明:子查询(表名1:a 表名2:b) 8y_(Iu|:
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) c9Cc%EK
5、说明:显示文章、提交人和最后回复时间 xx7&y!_
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b =5fY3%^b{
6、说明:外连接查询(表名1:a 表名2:b) YO?o$Hv16
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c :sLg$OF
7、说明:在线视图查询(表名1:a ) x>BFK@#
select * from (SELECT a,b,c FROM a) T where t.a > 1; )b=vBs`%
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 K7(k_4
select * from table1 where time between time1 and time2 >hq{:m
select a,b,c, from table1 where a not between 数值1 and 数值2 O'#;Ge/,
9、说明:in 的使用方法 &b*v7c=o
select * from table1 where a [not] in ('值1','值2','值4','值6') ,,80nW9E
10、说明:两张关联表,删除主表中已经在副表中没有的信息 LikCIO
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) "$K]+0ryG<
11、说明:四表联查问题: Z1+Ewq3m
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 ..... O{7#Xj
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12、说明:日程安排提前五分钟提醒 !TY0;is
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 *b0z/6
13、说明:一条sql 语句搞定数据库分页 qp#Euq6
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 V51kX{S
14、说明:前10条记录 1|ddG010
select top 10 * form table1 where 范围 ot!m=s
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.) &(Hw:W9
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) G?\eO&QG{"
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 Ex*{iJ;\
(select a from tableA ) except (select a from tableB) except (select a from tableC) mvt-+K?U
17、说明:随机取出10条数据 _LfbEv<,T
select top 10 * from tablename order by newid() 3$:F/H
18、说明:随机选择记录 q+<,FdG
select newid()
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19、说明:删除重复记录 r2i]9>w
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) /YJBRU2
20、说明:列出数据库里所有的表名 Otq1CD9
select name from sysobjects where type='U' D8PC;@m
21、说明:列出表里的所有的 cq
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select name from syscolumns where id=object_id('TableName') AGS(ud{
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。 (e!Yu#-
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 SAf)#HXa
显示结果: /n>vPJvz
type vender pcs .'38^
电脑 A 1 n<> ^cD
电脑 A 1 (f_J @n
光盘 B 2 q *Hg-J}
光盘 A 2 ^4Xsd h5
手机 B 3 }2m>S6""A
手机 C 3 TqV^\C?
23、说明:初始化表table1 \ISg6v{/
TRUNCATE TABLE table1 Le bc@,
24、说明:选择从10到15的记录 r)Zk- !1
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc `/N={
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三、技巧 &sBD0R(a
1、1=1,1=2的使用,在SQL语句组合时用的较多 opN4@a7l
"where 1=1" 是表示选择全部 "where 1=2"全部不选, QLHEzEvf{/
如: Jc]66
if @strWhere !='' LN<rBF[_:f
begin =-GxJPL
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ~Jsu"kr
end 88[u^aC
else /Ix5`Q)
begin F|.tn`j]U
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' '|5o(6u'
end y x#ub-A8
我们可以直接写成 /%p
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere _zzNF93Bn
2、收缩数据库 I!1+#0SG
--重建索引 _!Tjb^
DBCC REINDEX <Uf`'X\e6
DBCC INDEXDEFRAG Cd]A1<6s
--收缩数据和日志 a&)!zhVP
DBCC SHRINKDB S'ms>ZENC
DBCC SHRINKFILE HUCJA-OZGL
3、压缩数据库 ?vI2mra+
dbcc shrinkdatabase(dbname) o~"Y_dLsW
4、转移数据库给新用户以已存在用户权限 5_L,7\5#
exec sp_change_users_login 'update_one','newname','oldname' 0nB[Udk?
go FyPG5-
5、检查备份集 qIQ
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RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ,1~zMzw ^
6、修复数据库 VSV]6$~H
ALTER DATABASE [dvbbs] SET SINGLE_USER YPY,gR
GO ]$^HGmP
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ME]89 T&
GO 98?O[=
ALTER DATABASE [dvbbs] SET MULTI_USER -J#RGB{7
GO -m>3@"q
7、日志清除 =Bm|9A1
SET NOCOUNT ON \ )>#`X
DECLARE @LogicalFileName sysname, IqsUtWSp
@MaxMinutes INT, '!?t+L%gO
@NewSize INT >g~IP>
USE tablename -- 要操作的数据库名 t#y,9>6
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名
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@MaxMinutes = 10, -- Limit on time allowed to wrap log. 1n7'\esC*
@NewSize = 1 -- 你想设定的日志文件的大小(M) $G }9iV7
-- Setup / initialize h# Z,ud_
DECLARE @OriginalSize int P2C>IS
SELECT @OriginalSize = size P{_%p<:V
FROM sysfiles M3F1O6=4j
WHERE name = @LogicalFileName ONy\/lu|
SELECT 'Original Size of ' + db_name() + ' LOG is ' + E.ji;5
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + &N6[*7
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' t?Qbi)T=z
FROM sysfiles uW FyI"
WHERE name = @LogicalFileName Hy,""Py
CREATE TABLE DummyTrans h7TkMt[l
(DummyColumn char (8000) not null) +Ig%h[1a
DECLARE @Counter INT, *fv BB9raq
@StartTime DATETIME, :&:P4Y1
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@TruncLog VARCHAR(255) d]^m^
SELECT @StartTime = GETDATE(), 3^fwDt}
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' L+
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) AL,7rYZG$
EXEC (@TruncLog) JXq!v:w6
-- Wrap the log if necessary. B)L0hi
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired
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AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) Vky]In=
AND (@OriginalSize * 8 /1024) > @NewSize VmQ'
BEGIN -- Outer loop. mEi(DW)(
SELECT @Counter = 0 &=n/h5e0t&
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) :&'jh/vRN
BEGIN -- update 9y5JV3
INSERT DummyTrans VALUES ('Fill Log') r7R.dD/.
DELETE DummyTrans KfZb=v;-l
SELECT @Counter = @Counter + 1 3RvDX p
END r@vt.t0#
EXEC (@TruncLog) f>4|>kS
END g"kI1^[nj
SELECT 'Final Size of ' + db_name() + ' LOG is ' + tu* uQ:Ipk
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + }' Y)"8AIA
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' v'Ehr**]+
FROM sysfiles e?B}^Dk0i
WHERE name = @LogicalFileName $@]
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DROP TABLE DummyTrans r%iFsV_
SET NOCOUNT OFF Kz/,V6H:
8、说明:更改某个表 /3SEu(d!
exec sp_changeobjectowner 'tablename','dbo' _-543B}
9、存储更改全部表 p[].4_B;
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Tbv w?3
@OldOwner as NVARCHAR(128), ~tRGw^<9
@NewOwner as NVARCHAR(128) >$-YNZA
AS 4cPZGZ{U
DECLARE @Name as NVARCHAR(128) q165S
DECLARE @Owner as NVARCHAR(128) tK/,U
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DECLARE @OwnerName as NVARCHAR(128) Jp}\@T.
DECLARE curObject CURSOR FOR Ok{1{EmP
select 'Name' = name, IpSWg
'Owner' = user_name(uid) 4KR`
from sysobjects )1Y?S;
where user_name(uid)=@OldOwner !!V1#?0jw
order by name 2Vf242z_
OPEN curObject @n.n[zb\|
FETCH NEXT FROM curObject INTO @Name, @Owner i|AWaG)
WHILE(@@FETCH_STATUS=0) 8HJ,6L r;
BEGIN U.I
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if @Owner=@OldOwner vyJ8"
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begin \O;/wf0Hg
set @OwnerName = @OldOwner + '.' + rtrim(@Name) qhcx\eD:?
exec sp_changeobjectowner @OwnerName, @NewOwner |&W4Dkn
end 'xG J;pY
-- select @name,@NewOwner,@OldOwner 'bSWJ/;p)
FETCH NEXT FROM curObject INTO @Name, @Owner %,HUn`
END j3`YaWw
close curObject hi/d%lNZ
deallocate curObject \#VWZ\M8a
GO _
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10、SQL SERVER中直接循环写入数据 FJCORa@?_
declare @i int A s}L=2
set @i=1 1;S?9N_B
while @i<30 'v
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begin vazA@|^8
insert into test (userid) values(@i) Y`eF9Im,
set @i=@i+1 I%Yq86
end u%yYLpaKf
小记存储过程中经常用到的本周,本月,本年函数 qGMU>J.;c
Dateadd(wk,datediff(wk,0,getdate()),-1) 6k>5+ -&_
Dateadd(wk,datediff(wk,0,getdate()),6) ^--R#$X
Dateadd(mm,datediff(mm,0,getdate()),0) K\fD';
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) Y%0rji
Dateadd(yy,datediff(yy,0,getdate()),0) jnztCNaX
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) RN[x\" ,
上面的SQL代码只是一个时间段 n;kWAYgg
Dateadd(wk,datediff(wk,0,getdate()),-1) 5Ww,vSCV)
Dateadd(wk,datediff(wk,0,getdate()),6) M/9[P*
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就是表示本周时间段. Tsb}\
下面的SQL的条件部分,就是查询时间段在本周范围内的: N wNxO
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) \7*|u
而在存储过程中 'kC#GTZi
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) #\^=3A|b
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) phf{b+'#X