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。 |Fze9kZO
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一、基础 >*O5Ry:4
1、说明:创建数据库 ;c]O *\/
CREATE DATABASE database-name , vvfk=-
2、说明:删除数据库 t1
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drop database dbname ]<YS7.pT
3、说明:备份sql server QaEiP n~
--- 创建 备份数据的 device
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USE master aw lq/
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 52#
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--- 开始 备份 +,R!el!o~u
BACKUP DATABASE pubs TO testBack `%#_y67v
4、说明:创建新表 %nq<nfDT
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 2P'Vp7f6 Y
根据已有的表创建新表: :+QNN<
A:create table tab_new like tab_old (使用旧表创建新表) .j,xh )v"
B:create table tab_new as select col1,col2... from tab_old definition only s/J7z$NEU
5、说明:删除新表 $1d{R;b[
drop table tabname tAep_GR
6、说明:增加一个列 ?xMTO
Alter table tabname add column col type 3j$,L(
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。 hTZ6@i/pS
7、说明:添加主键: Alter table tabname add primary key(col) &Q"vXs6Gt
说明:删除主键: Alter table tabname drop primary key(col) Oz_CEMcy
8、说明:创建索引:create [unique] index idxname on tabname(col....) Zp_j\B
删除索引:drop index idxname RaTNA W)v>
注:索引是不可更改的,想更改必须删除重新建。 RWM~7^JA
9、说明:创建视图:create view viewname as select statement `g(#~0R
删除视图:drop view viewname k
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10、说明:几个简单的基本的sql语句 CpX[8>&osD
选择:select * from table1 where 范围 {P?DkUO}
插入:insert into table1(field1,field2) values(value1,value2) O{byMV{Ou
删除:delete from table1 where 范围 t'W6Fmwkx
更新:update table1 set field1=value1 where 范围 B[8RBTsA
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! [-Y~g%M
排序:select * from table1 order by field1,field2 [desc] |8k^jq
总数:select count as totalcount from table1 ]x8Y]wAU&{
求和:select sum(field1) as sumvalue from table1 g]44|9x(W
平均:select avg(field1) as avgvalue from table1 8,+T[S
最大:select max(field1) as maxvalue from table1 r/NaoIrJV
最小:select min(field1) as minvalue from table1 *1b0IQ$g
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11、说明:几个高级查询运算词 XZ$g~r
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A: UNION 运算符 mGP%"R2X
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。 }mZCQJ#`
B: EXCEPT 运算符 ^_G#JJ\@$
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。 &"tQpw5
C: INTERSECT 运算符 !7#*Wdt+P
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。 c"`HKfL
注:使用运算词的几个查询结果行必须是一致的。 gV ':Xe
12、说明:使用外连接 P*?2+.
A、left outer join: ^56D)A=
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。 u\xrC\Ka
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 MGwXZ7?E
B:right outer join: *) \y52z
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。 y}U'8*,
C:full outer join: Gk58VODo
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。 VOATza`
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二、提升 +dq2}gM
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) wp~KrUlR
法一:select * into b from a where 1<>1 T72Z<h|<
法二:select top 0 * into b from a Avljrds+7
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) zKYN5|17
insert into b(a, b, c) select d,e,f from b; h=YTgJ
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) <R2SV=]Sq#
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 {~EsO1p
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. =.m/X>
4、说明:子查询(表名1:a 表名2:b) *E|3Vy{4
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) r`)'Kd
5、说明:显示文章、提交人和最后回复时间 8r,0Qic2K
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b jgpF+V-n$
6、说明:外连接查询(表名1:a 表名2:b) MbTmdRf
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c z'>b)wY](
7、说明:在线视图查询(表名1:a ) LG(" <CU
select * from (SELECT a,b,c FROM a) T where t.a > 1; vPy."/[u
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 yMgS0
select * from table1 where time between time1 and time2 \!>qtFT
select a,b,c, from table1 where a not between 数值1 and 数值2 eeBw\f0
9、说明:in 的使用方法 Ix=(f0|
select * from table1 where a [not] in ('值1','值2','值4','值6') !]7L9TGn
10、说明:两张关联表,删除主表中已经在副表中没有的信息 ky]L`w
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ]wbV1Y"
11、说明:四表联查问题: 3<a|_(K
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 ..... Esj1Vv#
12、说明:日程安排提前五分钟提醒 @2$Uk!
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 YO@~y*,
13、说明:一条sql 语句搞定数据库分页 h:z$uG
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 li')U
14、说明:前10条记录 K7q R
select top 10 * form table1 where 范围 E%Ysyk
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.) e5n"(s"G*[
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ldaT:
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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'n
(select a from tableA ) except (select a from tableB) except (select a from tableC) ;t.)A3 PL
17、说明:随机取出10条数据 ="g9>
select top 10 * from tablename order by newid() q?0&0
18、说明:随机选择记录 1yc$b+TH
select newid() [A;0IjKam
19、说明:删除重复记录 R&/"?&pfa
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) =|
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20、说明:列出数据库里所有的表名 q{q;X{
select name from sysobjects where type='U' v+d`J55
21、说明:列出表里的所有的 1:I _;O_
select name from syscolumns where id=object_id('TableName') b^P\Kky
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 gb^'u
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type `7V'A
显示结果: ^NxKA'oWQ
type vender pcs &D7Mv5i0@
电脑 A 1 }qhND-9#@
电脑 A 1 9J}^{AA
光盘 B 2 G$lE0_j2{
光盘 A 2 +5Y;JL<%/
手机 B 3 ~^g*cA
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手机 C 3 %W2
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23、说明:初始化表table1 $cO-+Mr-~
TRUNCATE TABLE table1 Gx%f&H~Z^
24、说明:选择从10到15的记录 ch/DBu
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 'L%)B-,n
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三、技巧 cw~-%%/
1、1=1,1=2的使用,在SQL语句组合时用的较多 #<w2xR]:
"where 1=1" 是表示选择全部 "where 1=2"全部不选, dhr-tw
如: J>0RN/38o
if @strWhere !='' xwijCFI*
begin '^:q|h
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere uHt@;$9A
end ~2XiKY;W?
else 9@
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begin OL@' 1$/A
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' mGUG
end cN:ek|r
我们可以直接写成 !!v9\R4um
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere zgSv -h+f
2、收缩数据库 `S]DHxS
--重建索引 B!1L W4^
DBCC REINDEX ","to
DBCC INDEXDEFRAG DPlmrN9@=
--收缩数据和日志 XiyL563gh
DBCC SHRINKDB ,LDdL
DBCC SHRINKFILE #4^D'r>pJ
3、压缩数据库 >% E=l
dbcc shrinkdatabase(dbname) *iVv(xXgN
4、转移数据库给新用户以已存在用户权限 1KI5tf>>p
exec sp_change_users_login 'update_one','newname','oldname' @p9YHLxLjQ
go \.`{nq
5、检查备份集 O6\t_.
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 1F[W~@jW
6、修复数据库 ZX40-6#O
ALTER DATABASE [dvbbs] SET SINGLE_USER ue!wo-|#G
GO Q~)A
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DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK )m10IyUAY
GO 2TX.%%Ze
ALTER DATABASE [dvbbs] SET MULTI_USER kO8oH8Vt
GO 2D{`AJ
7、日志清除 Y:5Gp8Vi
SET NOCOUNT ON X0]5I0YP
DECLARE @LogicalFileName sysname, v,)vW5jGI
@MaxMinutes INT, yxy~N\0
@NewSize INT .$r7q[
USE tablename -- 要操作的数据库名 pIvr*UzY
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 {9h`h08?z
@MaxMinutes = 10, -- Limit on time allowed to wrap log. RV6|sN[x>
@NewSize = 1 -- 你想设定的日志文件的大小(M) yJHFo[wGMJ
-- Setup / initialize (!diPwcv
DECLARE @OriginalSize int ,mD{4 >7
SELECT @OriginalSize = size (fC U+
FROM sysfiles !;&{Q^}
WHERE name = @LogicalFileName MZ<BCRB
SELECT 'Original Size of ' + db_name() + ' LOG is ' + (L7%V !
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + +C`zI~8
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' R"{oj]d;$F
FROM sysfiles ,) 3Eog\-
WHERE name = @LogicalFileName KA]5tVQA
CREATE TABLE DummyTrans Vg1MA
(DummyColumn char (8000) not null) d)v'K5
DECLARE @Counter INT,
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@StartTime DATETIME, \yA*)X+
@TruncLog VARCHAR(255) SQI =D8
SELECT @StartTime = GETDATE(), #9@UzfZAwT
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' - f%J_`
DBCC SHRINKFILE (@LogicalFileName, @NewSize) .Gnzu"lod
EXEC (@TruncLog) )ZDqj
-- Wrap the log if necessary. 1H7bPl|
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 690;\O '
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) :3 By7BZgj
AND (@OriginalSize * 8 /1024) > @NewSize K}Rq<zW
BEGIN -- Outer loop. iVf8M$!m
SELECT @Counter = 0 9':MD0P/M
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) #~;:i
BEGIN -- update ;Qdw$NuW
INSERT DummyTrans VALUES ('Fill Log') Te&5IB-
DELETE DummyTrans ~#9(Q
SELECT @Counter = @Counter + 1 !l#n.Fx&3
END FKkL%:?
EXEC (@TruncLog) ,Q>wcE6v
END fdzaM&
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 1<&nHFJ;[
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + iKe68kx
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' CJ[^Fi?CH
FROM sysfiles >`Zw0S
WHERE name = @LogicalFileName APL #-`XC
DROP TABLE DummyTrans TWo.c _l
SET NOCOUNT OFF DzG$\%G2R}
8、说明:更改某个表 \kVi&X=q:
exec sp_changeobjectowner 'tablename','dbo' mpDQhD[n
9、存储更改全部表 aA&}=lm
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch =F90SyzTy
@OldOwner as NVARCHAR(128), g,""j`
@NewOwner as NVARCHAR(128) =&v&qne9
AS ]sV) '-
DECLARE @Name as NVARCHAR(128) CC{{@
DECLARE @Owner as NVARCHAR(128) ev%}\^Vl[
DECLARE @OwnerName as NVARCHAR(128) 8/+x1, S%
DECLARE curObject CURSOR FOR aj@<4A=;
select 'Name' = name, j\@osjUu
'Owner' = user_name(uid) 'mU7N<Q$qQ
from sysobjects ,L9ioYbp
where user_name(uid)=@OldOwner 9|1J pb
order by name *WZ?C|6+
OPEN curObject IRB BLXv7\
FETCH NEXT FROM curObject INTO @Name, @Owner }C9P--
WHILE(@@FETCH_STATUS=0) Rkz[x
BEGIN Sv|jR r'
if @Owner=@OldOwner '7/c7m/$X<
begin R7~#7qKQB
set @OwnerName = @OldOwner + '.' + rtrim(@Name) X1~ WQ?ww
exec sp_changeobjectowner @OwnerName, @NewOwner Y8%*S%yO
end vHxLn/
-- select @name,@NewOwner,@OldOwner m<| *
FETCH NEXT FROM curObject INTO @Name, @Owner G7d)X^q!xS
END KPMId`kf
close curObject cuo'V*nWQ
deallocate curObject ":,J<|Oy
GO Y SD|#0
10、SQL SERVER中直接循环写入数据 L&h90Az1W
declare @i int @6:J$B~)u
set @i=1 $z* Y:vFP
while @i<30 a) 5;Od
begin Vo:Gp
insert into test (userid) values(@i) =hDFpb,mr
set @i=@i+1 m #}%l3$
end (SGU]@)g
小记存储过程中经常用到的本周,本月,本年函数 s2Hx?~
Dateadd(wk,datediff(wk,0,getdate()),-1) 6F4OISy%3
Dateadd(wk,datediff(wk,0,getdate()),6) $kCLS7 *
Dateadd(mm,datediff(mm,0,getdate()),0) [nG@
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Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) oV Hh
Dateadd(yy,datediff(yy,0,getdate()),0) f<v:Tg.[
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) KJ;NcUq
上面的SQL代码只是一个时间段 a>XlkkX
Dateadd(wk,datediff(wk,0,getdate()),-1) T9=55tpG9
Dateadd(wk,datediff(wk,0,getdate()),6) m*Q*{M_e
就是表示本周时间段. 3X
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下面的SQL的条件部分,就是查询时间段在本周范围内的: ^=V b'g3P~
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) P
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而在存储过程中 76r RF
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) g6Nw].{
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) H_<hZUB