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。 9[Mu
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一、基础 zVu}7v()
1、说明:创建数据库 71_N9ub@z
CREATE DATABASE database-name 5 *_#"
2、说明:删除数据库 <vs.Ucxx
drop database dbname T[~X~dqwn"
3、说明:备份sql server _wBPn6gg`
--- 创建 备份数据的 device i^#RiCeo
USE master !?{5ET,gtN
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' v;SJgZK
--- 开始 备份
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BACKUP DATABASE pubs TO testBack e
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4、说明:创建新表 h(BN6ZrzKd
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) zx27aZ[
根据已有的表创建新表: <d4^gAfs*
A:create table tab_new like tab_old (使用旧表创建新表) "T PMSx&Ei
B:create table tab_new as select col1,col2... from tab_old definition only -UO$$)Q
5、说明:删除新表 lI9 3{!+>
drop table tabname ;I>`!|mT
6、说明:增加一个列 Liofv4![
Alter table tabname add column col type 3I]5DW %-
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。 VuGSP]$q
7、说明:添加主键: Alter table tabname add primary key(col) %llG/]q#
说明:删除主键: Alter table tabname drop primary key(col) 2bqwnRT}
8、说明:创建索引:create [unique] index idxname on tabname(col....) ^#+9v
删除索引:drop index idxname OX91b<A
注:索引是不可更改的,想更改必须删除重新建。 J{H475GqiT
9、说明:创建视图:create view viewname as select statement ;Bm{_$hf=
删除视图:drop view viewname [yz;OoA:;
10、说明:几个简单的基本的sql语句 rie1F,
选择:select * from table1 where 范围 N'4*L=Ut
插入:insert into table1(field1,field2) values(value1,value2) Gv`PCA@/d
删除:delete from table1 where 范围 ^-DK<jZ^
更新:update table1 set field1=value1 where 范围 xed$z
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! =Oy,SX
排序:select * from table1 order by field1,field2 [desc] PqfH}d0l
总数:select count as totalcount from table1 p?Y1^/
求和:select sum(field1) as sumvalue from table1 NFQ0/iuW
平均:select avg(field1) as avgvalue from table1 [*Lh4K
最大:select max(field1) as maxvalue from table1 K.z@Vx.
最小:select min(field1) as minvalue from table1 7Ev~yY;N
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11、说明:几个高级查询运算词 a}6Wo=
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A: UNION 运算符 STO6cNi
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。 w!61k \
B: EXCEPT 运算符 6b@:La
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。 y8\44WKW
C: INTERSECT 运算符 dD=dPi#
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。 xand%XNv
注:使用运算词的几个查询结果行必须是一致的。 h9No'!'!
12、说明:使用外连接 $///N+B
A、left outer join: Kpg]b"9.R
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。 v=!]t=P)t
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 vFQ'sd]C
B:right outer join: Nx~8]h1(
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。 8xLvpgcZ
C:full outer join: lV3\5AEW
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。 `w2hJP
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二、提升 $cnIsyKWY
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) DvU(rr\p
法一:select * into b from a where 1<>1 H.*XoktC]
法二:select top 0 * into b from a kf';"
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) Y7= *-
insert into b(a, b, c) select d,e,f from b; WJ8i,7
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) LXrnAt
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 Tw=Jc 's
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. s~,Y po?
4、说明:子查询(表名1:a 表名2:b) -|T.APxB
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) .#@*)1A#t
5、说明:显示文章、提交人和最后回复时间 &0~E+
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select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b ml\A)8O]j/
6、说明:外连接查询(表名1:a 表名2:b) LNtBYdB`pK
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c u`3J2,.
7、说明:在线视图查询(表名1:a ) )bXiw3'A
select * from (SELECT a,b,c FROM a) T where t.a > 1; (i1]+.
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 -b8Vz}Y
select * from table1 where time between time1 and time2 UO>ADRs}
select a,b,c, from table1 where a not between 数值1 and 数值2 2/3,%5j_
9、说明:in 的使用方法 O$+0 .
select * from table1 where a [not] in ('值1','值2','值4','值6') ;kDz9Va
10、说明:两张关联表,删除主表中已经在副表中没有的信息 Ru`&>E
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 7']n_-fu
11、说明:四表联查问题: 2eK!<Gj
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 ..... D:4Iex9$F"
12、说明:日程安排提前五分钟提醒 /^SIJS@^`>
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 zuwlVn
13、说明:一条sql 语句搞定数据库分页 N*y09?/h
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 Y xp.`
14、说明:前10条记录 ,3 =|a|p
select top 10 * form table1 where 范围 gs7h`5[es
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) f%<kcM2
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) iv*`.9TK-
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 hCS|(8g
(select a from tableA ) except (select a from tableB) except (select a from tableC) ]3nka$wA*
17、说明:随机取出10条数据 G(" S6u
select top 10 * from tablename order by newid() mII7p LbQ
18、说明:随机选择记录 .SzPig
select newid() -^yb[b,
19、说明:删除重复记录 t"4RGO)jh
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) `lygJI?H+{
20、说明:列出数据库里所有的表名 _~]~ssn,1
select name from sysobjects where type='U' Sc#B-4m
21、说明:列出表里的所有的 |*W_
select name from syscolumns where id=object_id('TableName') 9.)*z-f$
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。 Er509zZ,[
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 5n{J}0C
显示结果: $R6iG\V5
type vender pcs [;~:',vHQf
电脑 A 1 dnRbt{`jP
电脑 A 1 )IQ5Qu
光盘 B 2 5G
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光盘 A 2 B /q/6Pp
手机 B 3 PxE 0b0eo
手机 C 3 _sLSl;/t
23、说明:初始化表table1 #y;TSHx/
TRUNCATE TABLE table1 YD>5zV%!D
24、说明:选择从10到15的记录 RI.6.f1dy
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc =ie8{j2:
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三、技巧 !A_<(M<
1、1=1,1=2的使用,在SQL语句组合时用的较多 9)2kjBeb
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 9NzK1V0X
如: F3uR:)4<M
if @strWhere !='' -QPM$
begin xwvg@
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere DPV>2'
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end (S<Z@y+d
else <=O/_Iu(
begin (p6$Vgdt
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' R;yi58Be
end @bfW-\ I
我们可以直接写成 s0D,n1x
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere U-h'a:
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2、收缩数据库 "p Rr>F a
--重建索引 ui>0?O*G
DBCC REINDEX ?so=k&I-M
DBCC INDEXDEFRAG MawWgd*
--收缩数据和日志 SK][UxoHm
DBCC SHRINKDB b\
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DBCC SHRINKFILE dio<?6ZD9P
3、压缩数据库 $nf5bo/;
dbcc shrinkdatabase(dbname) 8VWkUsOoI
4、转移数据库给新用户以已存在用户权限 UYw_k\
exec sp_change_users_login 'update_one','newname','oldname' &Y`V A
go 5Yxs_t4
5、检查备份集 uDe%M
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' T{A5,85
6、修复数据库 |M;tAG$,"y
ALTER DATABASE [dvbbs] SET SINGLE_USER n8K FP
GO s8O.yL
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK hwD;1n
GO pwIu;:O!?
ALTER DATABASE [dvbbs] SET MULTI_USER Sh@en\m=#S
GO r}>q*yx:
7、日志清除 JXhHitUD
SET NOCOUNT ON n "J+?~9
DECLARE @LogicalFileName sysname, MJyz0.9 c
@MaxMinutes INT, @3aI7U/I
@NewSize INT J 7/)XS
USE tablename -- 要操作的数据库名 dRhsnT+KX
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 tJ qd
@MaxMinutes = 10, -- Limit on time allowed to wrap log. _x'?igy
@NewSize = 1 -- 你想设定的日志文件的大小(M) \>7hT;Av=G
-- Setup / initialize Id(wY$C&>
DECLARE @OriginalSize int ;:`0:Ao.
SELECT @OriginalSize = size 5YG%\
FROM sysfiles C@P4}X0,=
WHERE name = @LogicalFileName S&q(PI_"
SELECT 'Original Size of ' + db_name() + ' LOG is ' + I
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CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + {hRM=f7
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB'
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FROM sysfiles bMCy=5
WHERE name = @LogicalFileName +k?0C?/T;
CREATE TABLE DummyTrans s*3p*zf
(DummyColumn char (8000) not null) MJ%gF=$X
DECLARE @Counter INT, _v\L'`bif
@StartTime DATETIME, )a;ou>u
@TruncLog VARCHAR(255) j34L*?
SELECT @StartTime = GETDATE(), .ou#BWav/
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' &pk&8_=f
DBCC SHRINKFILE (@LogicalFileName, @NewSize) l,w$!FnmR
EXEC (@TruncLog) ajJ+Jn\
-- Wrap the log if necessary. G&DL)ePu]m
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 7j//x Tr}a
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) dH[T nqJn
AND (@OriginalSize * 8 /1024) > @NewSize PKK18E}{%^
BEGIN -- Outer loop. cy%S5Rz
SELECT @Counter = 0 I5$]{:L|9
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) oBpoZ @[Z
BEGIN -- update "4Bk
INSERT DummyTrans VALUES ('Fill Log') ?*K{1Ghf
DELETE DummyTrans <q<kqy5s-R
SELECT @Counter = @Counter + 1 ]N#%exBVo
END /t$J<bU
EXEC (@TruncLog) F-&=N {+
END P)k!#*
SELECT 'Final Size of ' + db_name() + ' LOG is ' + i^I
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CONVERT(VARCHAR(30),size) + ' 8K pages or ' + >`S $(f
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' C\RJ){dk
FROM sysfiles um}%<Cy[
WHERE name = @LogicalFileName ] l@Mo7|w
DROP TABLE DummyTrans a}#8n^2
SET NOCOUNT OFF y$h.k"x`
8、说明:更改某个表 ='U>P(
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exec sp_changeobjectowner 'tablename','dbo' d:"#_
9、存储更改全部表 J =j6rD
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch
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@OldOwner as NVARCHAR(128), $T-Pl57
@NewOwner as NVARCHAR(128) %fH&UFby
AS \(g/::|
DECLARE @Name as NVARCHAR(128) ^v+3qm@,
DECLARE @Owner as NVARCHAR(128) WA1h|:Z
DECLARE @OwnerName as NVARCHAR(128) grWmF3c#
DECLARE curObject CURSOR FOR ,!i!q[YkL9
select 'Name' = name, !STa}wl
'Owner' = user_name(uid) KbicP<
from sysobjects [i 7^a/e
where user_name(uid)=@OldOwner -l2aAK1M
order by name -rXo}I,VI
OPEN curObject "$6 .L^9W
FETCH NEXT FROM curObject INTO @Name, @Owner a"Q> K7K
WHILE(@@FETCH_STATUS=0) =j&qat
BEGIN 8+=-!":]
if @Owner=@OldOwner >x0)
begin zc4l{+3
set @OwnerName = @OldOwner + '.' + rtrim(@Name) : l&g5
exec sp_changeobjectowner @OwnerName, @NewOwner 7LZA!3
end //O9}-
-- select @name,@NewOwner,@OldOwner R&P}\cf8T
FETCH NEXT FROM curObject INTO @Name, @Owner VQe@H8>3
END H-ewO8@
close curObject <JkmJ/X
deallocate curObject %'vLkjI.
GO sQ05wAv
10、SQL SERVER中直接循环写入数据 Hi5}s
declare @i int 6M-Y`T`J
set @i=1 [:Y`^iR.
while @i<30 fk!P#
begin Y[p
insert into test (userid) values(@i) q?TI(J+/
set @i=@i+1 \-eDNwJ:#@
end *$/!.e
小记存储过程中经常用到的本周,本月,本年函数 oy<
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Dateadd(wk,datediff(wk,0,getdate()),-1) )(`HEl>-9c
Dateadd(wk,datediff(wk,0,getdate()),6) ,lUr[xzV
Dateadd(mm,datediff(mm,0,getdate()),0) oe,37xa4
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) UP?]5x>
Dateadd(yy,datediff(yy,0,getdate()),0) XaH%i~}3
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) !^m,v19Ds<
上面的SQL代码只是一个时间段 uL1$yf'
Dateadd(wk,datediff(wk,0,getdate()),-1) 1 ^q~NYTK
Dateadd(wk,datediff(wk,0,getdate()),6) P S [ifC
就是表示本周时间段. eT<T[; m
下面的SQL的条件部分,就是查询时间段在本周范围内的: ,{rm<M.)
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ~SD8#;v2
而在存储过程中 )HPe}(ypt
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) hDAxX=FM
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) L-V+ `![{