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。 _7^4sR8=
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一、基础 |K7zN\
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1、说明:创建数据库 }BR@vY'd
CREATE DATABASE database-name bAd$
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2、说明:删除数据库 Ie<`WU K
drop database dbname MT?;9ZV}
3、说明:备份sql server ^o|Gx
--- 创建 备份数据的 device vz^w%67&
USE master ~8htg8CZ`
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' (mvzGXNz4
--- 开始 备份 /8s+eHn&%
BACKUP DATABASE pubs TO testBack 3P&K<M#\
4、说明:创建新表 8'nxc#&
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) Mu~DB:Y9e
根据已有的表创建新表: PrZs@ Y
A:create table tab_new like tab_old (使用旧表创建新表) 5PCMxjon
B:create table tab_new as select col1,col2... from tab_old definition only jcY:a0 [{D
5、说明:删除新表 YtWO=+rX
drop table tabname Fh3>y2`/
6、说明:增加一个列 Wu\szI"
Alter table tabname add column col type >&`S$1 o
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。 m:sT)
7、说明:添加主键: Alter table tabname add primary key(col) p2\mPFxEP
说明:删除主键: Alter table tabname drop primary key(col) FK:Tni
8、说明:创建索引:create [unique] index idxname on tabname(col....) \{Yi7V
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删除索引:drop index idxname .dr-I7&!
注:索引是不可更改的,想更改必须删除重新建。 1~|o@CO
9、说明:创建视图:create view viewname as select statement 8}A+{xVp8
删除视图:drop view viewname J8>8@m6
10、说明:几个简单的基本的sql语句 0IP5&[-P
选择:select * from table1 where 范围 HK/T`p#
插入:insert into table1(field1,field2) values(value1,value2) *It`<F|
删除:delete from table1 where 范围 R{X@@t9@
更新:update table1 set field1=value1 where 范围 tsqkV7?
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! XXe?@w2{
排序:select * from table1 order by field1,field2 [desc] FVw4BUOmi
总数:select count as totalcount from table1 :v(fgS2\
求和:select sum(field1) as sumvalue from table1 -9(9LU2
平均:select avg(field1) as avgvalue from table1 0~;Owu
最大:select max(field1) as maxvalue from table1 SZ*Nr=X
最小:select min(field1) as minvalue from table1 TSPFi0PP
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11、说明:几个高级查询运算词 $vQ#ah/k
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A: UNION 运算符 EU0b>2n4
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 Q^_*&},V
B: EXCEPT 运算符 QUSyVp{$
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。 lCznH?[
C: INTERSECT 运算符 ujt0?DM
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。 lls-Nir%
注:使用运算词的几个查询结果行必须是一致的。 H`XE5Hk)P%
12、说明:使用外连接
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A、left outer join: @ 7WWoy
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。
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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 SCUsDr+.
B:right outer join: :hA=(iz
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。 |hlc#t?
C:full outer join: ];n3H~2
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。 6n
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二、提升 ]l~TI8gC
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) /%P|<[<
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法一:select * into b from a where 1<>1 x_yQoae
法二:select top 0 * into b from a $^ wqoW%t
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) "G+g(?N]j
insert into b(a, b, c) select d,e,f from b; qVpV ZH!
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) F"?OLV1B&
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 @S%ogZz*m
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. Z fQzA}QD
4、说明:子查询(表名1:a 表名2:b) uq~Z
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) Vp5i i]B4
5、说明:显示文章、提交人和最后回复时间 tt=JvI9>
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b x)h|!T=B~
6、说明:外连接查询(表名1:a 表名2:b) :zWI"
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 5R?[My
7、说明:在线视图查询(表名1:a ) 2(<2Gnpl
select * from (SELECT a,b,c FROM a) T where t.a > 1; ST*\ Q
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 +5>*$L%8T`
select * from table1 where time between time1 and time2 1%R8q=_
select a,b,c, from table1 where a not between 数值1 and 数值2 n&4 4Acs[
9、说明:in 的使用方法 *T+Bjj;w
select * from table1 where a [not] in ('值1','值2','值4','值6') ^Qx
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10、说明:两张关联表,删除主表中已经在副表中没有的信息 -F+
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delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) &:3uK`
11、说明:四表联查问题: LMF@-j%
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 ..... N"+o=nS
12、说明:日程安排提前五分钟提醒 tcm?qro)
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 XlPi)3m4/S
13、说明:一条sql 语句搞定数据库分页 ^^O @ [_
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 5Wyo!pRi
14、说明:前10条记录 L93PDp4v
select top 10 * form table1 where 范围 "Q>gQKgL
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.) ]rpU3 3
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) }#0i1]n$D
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 \m\E*c
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(select a from tableA ) except (select a from tableB) except (select a from tableC) PqhR^re0.
17、说明:随机取出10条数据 6hW ~Q
select top 10 * from tablename order by newid() !(-lY(x
18、说明:随机选择记录 R[%ZyQ_
select newid() Ep.Q&(D
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19、说明:删除重复记录 Hw(_l,Xf
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) "k0b j>
20、说明:列出数据库里所有的表名 =F B[<%
select name from sysobjects where type='U' gE_i#=bw
21、说明:列出表里的所有的 m#^ua^JV
select name from syscolumns where id=object_id('TableName') f<$>?o&y
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。 g"F&~y/p
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 +kMVl_`V
显示结果: ) Ekd
type vender pcs ~o+:M0)}
电脑 A 1 jgz}
电脑 A 1 X*Qtbm,
光盘 B 2 uVQH,NA,
光盘 A 2 b `7vWyp
手机 B 3 wOlnDQs
手机 C 3 '#;%=+=;
23、说明:初始化表table1 ;$\?o
TRUNCATE TABLE table1 GmONhh(k
24、说明:选择从10到15的记录 #D qVh!t"
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc +J`HI1
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三、技巧 vjzpU(Sq#
1、1=1,1=2的使用,在SQL语句组合时用的较多 ;VLv2J*
"where 1=1" 是表示选择全部 "where 1=2"全部不选, e\[z Q
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如: E/OJ}3Rf
if @strWhere !='' S~ff<A>f
begin %ja8DRQ.
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere Dm")\"5\?
end _N-.=86*
else !bPsJbIo>
begin T[z}^"
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' g?}$"=B
end "L(4 EcO@
我们可以直接写成 /F(wb_!
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere vLc7RL
2、收缩数据库 X:un4B}O
--重建索引 e1EFZ,EcaO
DBCC REINDEX kPt] [1jo
DBCC INDEXDEFRAG 6c?;-5.
--收缩数据和日志 U:a-Wi+
DBCC SHRINKDB 5*q!:$
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DBCC SHRINKFILE FLqF!N\G
3、压缩数据库 L$Uy
dbcc shrinkdatabase(dbname) 8@}R_GZc
4、转移数据库给新用户以已存在用户权限 +# 38
exec sp_change_users_login 'update_one','newname','oldname' N y\c>$z
go {x-iBg9#l2
5、检查备份集 D)]U+Qk
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' fpDx)lQ
6、修复数据库 #]~l]Eq
ALTER DATABASE [dvbbs] SET SINGLE_USER gG 9e.++:
GO %X--`91|u
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK _D{V(c<WD
GO \BoRYb9h
ALTER DATABASE [dvbbs] SET MULTI_USER w;=fi}<G|e
GO A<1:vV
7、日志清除 [32]wgw+{1
SET NOCOUNT ON e]1&f.K
DECLARE @LogicalFileName sysname, z<T(afM{*
@MaxMinutes INT,
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@NewSize INT n%SR5+N"
USE tablename -- 要操作的数据库名 6 aE:vR2
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 7lC );
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ')bas#=uP
@NewSize = 1 -- 你想设定的日志文件的大小(M) ']bpsn
-- Setup / initialize l@h|os
DECLARE @OriginalSize int MM+xm{4l
SELECT @OriginalSize = size Ew&pwsQ
FROM sysfiles *FINNNARB
WHERE name = @LogicalFileName efc<lSUR
SELECT 'Original Size of ' + db_name() + ' LOG is ' + ?)Psf/
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + -w[j`}([P9
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' C\Y%FTS:
FROM sysfiles h~!KNF*XW
WHERE name = @LogicalFileName >nqDUGnEo>
CREATE TABLE DummyTrans v>p UVM
(DummyColumn char (8000) not null) &gP/<!#
DECLARE @Counter INT, *an^
0
@StartTime DATETIME, L,(H(GeX
@TruncLog VARCHAR(255) 3U_-sMOB|
SELECT @StartTime = GETDATE(), ,n}h_ct
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ~ x!"(
DBCC SHRINKFILE (@LogicalFileName, @NewSize) d4 Hpe>
EXEC (@TruncLog) Wk0"U
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-- Wrap the log if necessary. p)dD{+"/2
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired +b9gP\Hke
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) /M0A9ZT[
AND (@OriginalSize * 8 /1024) > @NewSize \!+#9sq0
BEGIN -- Outer loop. ![>j`i
SELECT @Counter = 0 $$,/F
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ~36)3W[4
BEGIN -- update
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INSERT DummyTrans VALUES ('Fill Log') 'e/= !"T
DELETE DummyTrans "vH>xBR[%
SELECT @Counter = @Counter + 1 xw>\6VNt
END oHW:s96e
EXEC (@TruncLog) o'Uaz*-po
END _3;vir%)
SELECT 'Final Size of ' + db_name() + ' LOG is ' + Epl\(
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + DCv=*=6w
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' {\SJr:
FROM sysfiles LNA5!E
WHERE name = @LogicalFileName _gLj(<^9
DROP TABLE DummyTrans r Ljb'\<*
SET NOCOUNT OFF 0LjF$3GpZ
8、说明:更改某个表 g }%$VUSA
exec sp_changeobjectowner 'tablename','dbo' nn1T5;
9、存储更改全部表 bm</qF'T6
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch (3_m[N\F
@OldOwner as NVARCHAR(128), b_'VWd:am
@NewOwner as NVARCHAR(128) "-WEUz
AS Bb~Q]V=x;
DECLARE @Name as NVARCHAR(128) h@^d
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DECLARE @Owner as NVARCHAR(128) ; qQ* p
DECLARE @OwnerName as NVARCHAR(128) ^#V7\;v$G
DECLARE curObject CURSOR FOR cLZaQsS%
select 'Name' = name, ~!PaBS3A
'Owner' = user_name(uid) Xcy Xju#"p
from sysobjects c=^A3[AM
where user_name(uid)=@OldOwner [}GPo0GY
order by name [!<W{ ($5
OPEN curObject M9t`w-@_w
FETCH NEXT FROM curObject INTO @Name, @Owner /^2&@P7
WHILE(@@FETCH_STATUS=0) wT taj08D
BEGIN A#&,S4Wi|
if @Owner=@OldOwner 4P>4d +
begin Dh4EP/=z
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 'X$J+s}6&
exec sp_changeobjectowner @OwnerName, @NewOwner 68!W~%?pR
end &4dh $w]q
-- select @name,@NewOwner,@OldOwner kT=KxS{
FETCH NEXT FROM curObject INTO @Name, @Owner 1luRTI8^
END ?}n\&|+
close curObject 19g-#H!
deallocate curObject qgk-[zW#
GO %VSjMZ
10、SQL SERVER中直接循环写入数据 odm!}stus
declare @i int c9
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set @i=1 b:c$EPK
while @i<30 d:_3V rRZ
begin
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insert into test (userid) values(@i) ]y**ZFA
set @i=@i+1 g]ct6-m
end a%IJ8t+mn
小记存储过程中经常用到的本周,本月,本年函数 BM }{};p6
Dateadd(wk,datediff(wk,0,getdate()),-1) }OJ,<!v2pc
Dateadd(wk,datediff(wk,0,getdate()),6) 2`]`nTz,
Dateadd(mm,datediff(mm,0,getdate()),0) G]$.bq[v
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) }(yX$ 3?`
Dateadd(yy,datediff(yy,0,getdate()),0) ;ATn&
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) _
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上面的SQL代码只是一个时间段 G<MX94?
Dateadd(wk,datediff(wk,0,getdate()),-1) D2@J4;UW*W
Dateadd(wk,datediff(wk,0,getdate()),6) 8M_p'AR\,y
就是表示本周时间段. ^&Re-{ES]
下面的SQL的条件部分,就是查询时间段在本周范围内的: =8p *Ijs
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 1Fs:&* =
而在存储过程中 hE9UWa.Q>
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) e=).0S`*F
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) Mqk[+n