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。 8(ZQD+U(9F
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一、基础 ptUnV3h
1、说明:创建数据库 yy%J{;
CREATE DATABASE database-name NjMo"1d
2、说明:删除数据库 7^:s/xHO*
drop database dbname or(Z-8a_
3、说明:备份sql server 0C0iAp
--- 创建 备份数据的 device BB~Qs
USE master $o-s?";
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 73P(oVj<
--- 开始 备份 YRB,jwne
BACKUP DATABASE pubs TO testBack 9=h A#t.#
4、说明:创建新表 MF=@PE][
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) $rf5\_G,96
根据已有的表创建新表: sYeZ.MacU
A:create table tab_new like tab_old (使用旧表创建新表) vZ|m3;X
B:create table tab_new as select col1,col2... from tab_old definition only Bm^vKzp
5、说明:删除新表 -N9U lW2S
drop table tabname lPx4I
6、说明:增加一个列 1z{AzpMZ
Alter table tabname add column col type )82x)c<e
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。 n|{x\@VeF
7、说明:添加主键: Alter table tabname add primary key(col) |3vQmd !2}
说明:删除主键: Alter table tabname drop primary key(col) >\MV/!W
8、说明:创建索引:create [unique] index idxname on tabname(col....) ;o#dmG
删除索引:drop index idxname .O~)zMx
注:索引是不可更改的,想更改必须删除重新建。 vk{dL'
9、说明:创建视图:create view viewname as select statement $S6AqUk$
删除视图:drop view viewname {GZHD^Ce
10、说明:几个简单的基本的sql语句 3vmZB2QG
选择:select * from table1 where 范围 F%L^k.y$
插入:insert into table1(field1,field2) values(value1,value2) bPiJCX0d
删除:delete from table1 where 范围 V5M_N;h
更新:update table1 set field1=value1 where 范围 y_\vXY'
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ;c~6^s`2
排序:select * from table1 order by field1,field2 [desc] %1xo|6hm-
总数:select count as totalcount from table1 tTC[^Dji
求和:select sum(field1) as sumvalue from table1 b[H& vp
平均:select avg(field1) as avgvalue from table1 ?. CA9!|
最大:select max(field1) as maxvalue from table1 @|r*yi
最小:select min(field1) as minvalue from table1 Rh,*tS
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11、说明:几个高级查询运算词 1P&c:n
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A: UNION 运算符 ;clF\K>
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。 ]yA|
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B: EXCEPT 运算符 (l9U7^S"{K
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。 !*N#}6Jd
C: INTERSECT 运算符 L;>tuJY1
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。 oE)tK1>;H
注:使用运算词的几个查询结果行必须是一致的。 ~M+|g4W%
12、说明:使用外连接 ]w! x
A、left outer join: CShVJ:u+K\
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。 R)ejIKtY
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 par
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B:right outer join: %I[(`nb
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。 .-fJ\`^mi
C:full outer join: hyFq>XFo
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。 q4Qm:|-
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二、提升 miEfxim
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) zN*/G6>A
法一:select * into b from a where 1<>1 NhXTt!S6C
法二:select top 0 * into b from a 3,W2CN}
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) Peh(*D{
insert into b(a, b, c) select d,e,f from b; $0NWX
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) ]MRE^Je\h
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 8K7zh.E
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 7DXT1+t
4、说明:子查询(表名1:a 表名2:b) I3p ~pt2
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) 6D@tCmmq
5、说明:显示文章、提交人和最后回复时间 'd(OFE-hn
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b KhYGiVA
6、说明:外连接查询(表名1:a 表名2:b) cBiv=!n
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Ond"Eq=r
7、说明:在线视图查询(表名1:a ) R2Lq,(@-
select * from (SELECT a,b,c FROM a) T where t.a > 1; 9kWyO:a_(
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 f!eC|:D
select * from table1 where time between time1 and time2 pNCk~OM
select a,b,c, from table1 where a not between 数值1 and 数值2 !JJCG
9、说明:in 的使用方法 ey@y?X=
select * from table1 where a [not] in ('值1','值2','值4','值6') JaiYVx(
10、说明:两张关联表,删除主表中已经在副表中没有的信息 -9\O$ I-3
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 9T`xW]Zf
11、说明:四表联查问题: )
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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 ..... q$0^U{j/
12、说明:日程安排提前五分钟提醒 VNx}ADXu ]
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 e*:[#LJ]C
13、说明:一条sql 语句搞定数据库分页 E&jngxlN
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 mRxL%!
14、说明:前10条记录 >{$;O
select top 10 * form table1 where 范围 qXCl6Yo8
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.) :Dw;RcZQ
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ` L6H2:pf
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 ^7vhize
(select a from tableA ) except (select a from tableB) except (select a from tableC) rmk'{"
17、说明:随机取出10条数据 J9mLW}I?NW
select top 10 * from tablename order by newid() r"zW=9 O=
18、说明:随机选择记录 >dn[oS,
select newid() w' #VN|;;!
19、说明:删除重复记录 \$<kJ||lS
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) GK2IY
20、说明:列出数据库里所有的表名 3q{H=6
select name from sysobjects where type='U' JIjqGxR
21、说明:列出表里的所有的 84cmPnaT
select name from syscolumns where id=object_id('TableName') :~{XL >:S
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。 QaUh+k<6
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 &B/cy<;y,
显示结果: *<OWd'LI
type vender pcs yAi#Y3!::
电脑 A 1 p$0;~1vH
电脑 A 1 6WzE'0Nyr
光盘 B 2 qL,QsRwN
光盘 A 2 #}^ZxEU
手机 B 3 T<mk98CdE
手机 C 3 g*AnrQ}P
23、说明:初始化表table1 6oL-Atf
TRUNCATE TABLE table1 KAO}*?
24、说明:选择从10到15的记录 1Hy
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Bz }Kdyur
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三、技巧 XCDHd
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1、1=1,1=2的使用,在SQL语句组合时用的较多 plv"/K JM
"where 1=1" 是表示选择全部 "where 1=2"全部不选, HEhdV5B
如: NGd|7S[^+c
if @strWhere !='' P>0j]?RB
begin -!I.:97 N
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere (uD(,3/Cw
end ,.x5
else YEF%l'm(\
begin <YUc?NF
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' Fx/9T2%=
end >Czcs=(L.k
我们可以直接写成 {(7Dz*0
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere psta&u\ q
2、收缩数据库 );@@>~
--重建索引 @|j`I1r.A
DBCC REINDEX f>;5ZE4Zu
DBCC INDEXDEFRAG tI{pu}/"#
--收缩数据和日志 /e!/
DBCC SHRINKDB UFyGp>/06
DBCC SHRINKFILE R5H
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3、压缩数据库 v}M, M&?
dbcc shrinkdatabase(dbname) '.#KkvE##
4、转移数据库给新用户以已存在用户权限 ?MPM@9
exec sp_change_users_login 'update_one','newname','oldname' (t&P.N/
go /#G^?2oM
5、检查备份集 O (tcu@vfl
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' BO#fzq%
6、修复数据库 fp:j~a>E
ALTER DATABASE [dvbbs] SET SINGLE_USER MVe5j+8
GO IhJ _Yed
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK C'
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GO 3Nsb@0
ALTER DATABASE [dvbbs] SET MULTI_USER TXH: + m c
GO 6aX m9J
7、日志清除 b,#cc>76\
SET NOCOUNT ON ahhVl=9/ao
DECLARE @LogicalFileName sysname, ygd'Nh!@
@MaxMinutes INT, #D
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@NewSize INT <T+Pw7X
USE tablename -- 要操作的数据库名 $lU~3I)
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 u)t1t69T\g
@MaxMinutes = 10, -- Limit on time allowed to wrap log. #ie{!Mh
@NewSize = 1 -- 你想设定的日志文件的大小(M) +G7A.d`V}
-- Setup / initialize j &)|nK;}
DECLARE @OriginalSize int |2
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SELECT @OriginalSize = size Z@t).$
FROM sysfiles U:J~Oy_Z
WHERE name = @LogicalFileName hh |'Uq3
SELECT 'Original Size of ' + db_name() + ' LOG is ' + `Rm2G
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + "sUe:F;
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' VS%8f.7ep
FROM sysfiles qusgX;)
WHERE name = @LogicalFileName BaR9X ?~O$
CREATE TABLE DummyTrans ,Uc\
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(DummyColumn char (8000) not null) Q5Y4@
DECLARE @Counter INT, k#5S'sCF<
@StartTime DATETIME, "3Ag+>tuRW
@TruncLog VARCHAR(255) [j1SX-NX
SELECT @StartTime = GETDATE(), 7`~h'(k
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 4:nmo@K&~
DBCC SHRINKFILE (@LogicalFileName, @NewSize) !#f4t]FM`B
EXEC (@TruncLog) deda=%w0
-- Wrap the log if necessary. z=?ainnKx
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Nr|.]=K)5n
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) -XPGl
AND (@OriginalSize * 8 /1024) > @NewSize o5BOe1_Pw
BEGIN -- Outer loop. Gvtd )9^<
SELECT @Counter = 0 &.K8cphj
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) C3G?dZKv2
BEGIN -- update 8ftLYMX@
INSERT DummyTrans VALUES ('Fill Log') rQ30)5^V|
DELETE DummyTrans ,HUs MCXQ
SELECT @Counter = @Counter + 1 b3#c0GL
END (xG#D;M0
EXEC (@TruncLog) w^A8ZT0^7
END |b'tf:l
SELECT 'Final Size of ' + db_name() + ' LOG is ' + yXg783B|v
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + IW$&V``v
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' oT\B-lx
FROM sysfiles ;}.jRmnJ
WHERE name = @LogicalFileName /+JCi6{sHS
DROP TABLE DummyTrans ag:#82C
SET NOCOUNT OFF JBeC\ \QX
8、说明:更改某个表 f$*M;|c1c/
exec sp_changeobjectowner 'tablename','dbo' v?K
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9、存储更改全部表
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CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch uQ5NN*C=
@OldOwner as NVARCHAR(128), K{x<zv&,
@NewOwner as NVARCHAR(128) MGN*i9CE
AS lBD{)Va
DECLARE @Name as NVARCHAR(128) yE{l
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DECLARE @Owner as NVARCHAR(128) CW*6 -q
DECLARE @OwnerName as NVARCHAR(128) T~ /Bf
DECLARE curObject CURSOR FOR *h@nAB\3
select 'Name' = name, <saS2.4
'Owner' = user_name(uid) 7M3q|7?
from sysobjects ^}U{O A
where user_name(uid)=@OldOwner }x~|XbG
order by name <!5N=-
OPEN curObject !+U#^2Gz
FETCH NEXT FROM curObject INTO @Name, @Owner jcXb@FE6
WHILE(@@FETCH_STATUS=0) L7X._XBO[
BEGIN &|n*&@fF
if @Owner=@OldOwner Af5In9WB5
begin wW6?.}2zU
set @OwnerName = @OldOwner + '.' + rtrim(@Name) vkc(-n
exec sp_changeobjectowner @OwnerName, @NewOwner HR['y9U
end " &p\pR~
-- select @name,@NewOwner,@OldOwner i*.Z~$
FETCH NEXT FROM curObject INTO @Name, @Owner vQc>jmS+n
END ]9R?2{"K
close curObject K~x G+Kh
deallocate curObject YRW<n9=3
GO jM2gu~
10、SQL SERVER中直接循环写入数据 oJ{)0;<~L
declare @i int 4w2V["?X1
set @i=1 f>#\'+l'
while @i<30 oYlq1MB?
begin gA" =so
insert into test (userid) values(@i) o~mY,7@a
set @i=@i+1 >Q[]i4*A
end kki]6_/n
小记存储过程中经常用到的本周,本月,本年函数 P:ys--$"
Dateadd(wk,datediff(wk,0,getdate()),-1) b]hRmW
Dateadd(wk,datediff(wk,0,getdate()),6) =1VY/sv
Dateadd(mm,datediff(mm,0,getdate()),0) Da?0B9'
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) k(u W( 6
Dateadd(yy,datediff(yy,0,getdate()),0) '9{H(DA
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) JeWW~y`e?{
上面的SQL代码只是一个时间段 d!Y,i!l!
Dateadd(wk,datediff(wk,0,getdate()),-1) ZZ[5Z=te?
Dateadd(wk,datediff(wk,0,getdate()),6) <%qbU-
就是表示本周时间段. 9#O"^.Z !
下面的SQL的条件部分,就是查询时间段在本周范围内的: w2/%e$D!9
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) J\m7U
而在存储过程中 m[ifcDZ(e
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) -']#5p l
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) h8pc<t\6