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。 Nmz5:Rq
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一、基础 #rX^)2
1、说明:创建数据库 ai$l7]7
CREATE DATABASE database-name *W\ 3cS
2、说明:删除数据库 qfl!>
drop database dbname KJoa^e;~
3、说明:备份sql server X5/j8=G H`
--- 创建 备份数据的 device 0vfMJzk
USE master j[gqS%
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 9`/e=RL
--- 开始 备份 ,dQ*0XO!
BACKUP DATABASE pubs TO testBack 8iY.!.G#|
4、说明:创建新表 *Ci&1Mu^Z
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) q;nAq%
根据已有的表创建新表: 13/,^?
A:create table tab_new like tab_old (使用旧表创建新表) ffL]_E
B:create table tab_new as select col1,col2... from tab_old definition only &%j`WF4p
5、说明:删除新表 z_xy*Iif
drop table tabname 9_5>MmiB
6、说明:增加一个列 6jc5B#
Alter table tabname add column col type b}Gm{;s!
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 L]z8'n,
7、说明:添加主键: Alter table tabname add primary key(col) YT!iI
说明:删除主键: Alter table tabname drop primary key(col) @-S7)h>~
8、说明:创建索引:create [unique] index idxname on tabname(col....) :2c(.-[`
删除索引:drop index idxname N\ Mdia
注:索引是不可更改的,想更改必须删除重新建。 4h!yh2c..
9、说明:创建视图:create view viewname as select statement u;nn:K1QFr
删除视图:drop view viewname n$SL"iezW?
10、说明:几个简单的基本的sql语句 bS8$[7OhX
选择:select * from table1 where 范围 7=fNvES2
插入:insert into table1(field1,field2) values(value1,value2) xI?'Nh
删除:delete from table1 where 范围 TDR|*Cs
更新:update table1 set field1=value1 where 范围 Q3l>xh
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! |+Rx)
排序:select * from table1 order by field1,field2 [desc] v1yB
总数:select count as totalcount from table1 !%t@wQ]\hG
求和:select sum(field1) as sumvalue from table1 `;}qjm0a
平均:select avg(field1) as avgvalue from table1 nw/g[/<;
最大:select max(field1) as maxvalue from table1 Zc_F"KJL
最小:select min(field1) as minvalue from table1 6/wC StZ
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11、说明:几个高级查询运算词 #pAN
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A: UNION 运算符 B^TgEr
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 I/St=-;
B: EXCEPT 运算符 x'}zNEXI
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 K{I "2c
C: INTERSECT 运算符 5Xxdm-0
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 :dbO|]Xf
注:使用运算词的几个查询结果行必须是一致的。 Y54yojvV
12、说明:使用外连接 +76ao7d.
A、left outer join: ?H_@/?
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 D]iyr>V6'
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 8~,zv_Pl
B:right outer join: 4>d]0=x
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 8u)>o*
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C:full outer join: k8n9zJ8
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 sSKD"
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二、提升 R$u1\r1I
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) F7C+uGTs
法一:select * into b from a where 1<>1 4Hf'/%kW
法二:select top 0 * into b from a XLiwE$:t%
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ~5|R`%
insert into b(a, b, c) select d,e,f from b; l=P)$O|=w
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) VSUWX1k4%
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 `*Wg&u
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. \25EI]
4、说明:子查询(表名1:a 表名2:b) :&&s*_
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) \>oy2{=;'
5、说明:显示文章、提交人和最后回复时间 oc-&}R4=
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b e@O]c"
6、说明:外连接查询(表名1:a 表名2:b) 5.\|*+E~
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c `j'1V1
7、说明:在线视图查询(表名1:a ) |AExaO"jk
select * from (SELECT a,b,c FROM a) T where t.a > 1; k fY;
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 3jfAv@I ~
select * from table1 where time between time1 and time2 wU'+4N".
select a,b,c, from table1 where a not between 数值1 and 数值2 J=kf KQV
9、说明:in 的使用方法 +pK 35u
select * from table1 where a [not] in ('值1','值2','值4','值6') EFtn!T
10、说明:两张关联表,删除主表中已经在副表中没有的信息 //r)dN^
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) s."N7F
11、说明:四表联查问题: b~<V}tJ
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 ..... X<Xiva85
12、说明:日程安排提前五分钟提醒 WaX!y$/z
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 Dby|l#X
13、说明:一条sql 语句搞定数据库分页 \uo{I~Qd
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 Ed0}$b
14、说明:前10条记录 nZYO}bv\
select top 10 * form table1 where 范围 j7I?K
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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.) kene'
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select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ,V5fvHPH)8
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 #$U/*~m $
(select a from tableA ) except (select a from tableB) except (select a from tableC) @[\zO'|
17、说明:随机取出10条数据 0RSzDgX
select top 10 * from tablename order by newid() 3e-E/6zH6
18、说明:随机选择记录 e+#k\x
select newid() Ht}?=ZzW
19、说明:删除重复记录 Z-}A"n
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ql5&&e=-
20、说明:列出数据库里所有的表名 W4P\HM>2
select name from sysobjects where type='U' <h+UC# .x
21、说明:列出表里的所有的 FD%OG6db];
select name from syscolumns where id=object_id('TableName') (u@X5O(a
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。 7$0bgWi
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 VL"Cxs
显示结果: =_N$0
type vender pcs !w/fwOo
电脑 A 1 u!+;Iy7
电脑 A 1 o)b-fAd@$
光盘 B 2 `l70i2xcj
光盘 A 2 V#Y"0l+~
手机 B 3 V4Qy^nn1
手机 C 3 "85)2*+
23、说明:初始化表table1 /={N^8^=x
TRUNCATE TABLE table1 u^'X>n)oL#
24、说明:选择从10到15的记录 8ZjRMr}
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc `{IL.9M!f
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三、技巧 1x##b[LC
1、1=1,1=2的使用,在SQL语句组合时用的较多 /Wl8Jf7'
"where 1=1" 是表示选择全部 "where 1=2"全部不选, rOYYZ)Qw
如: plr3&T~,&S
if @strWhere !='' kbH@h2Ww
begin &N/dxKZcc
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ]sP
end Zv
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else ;5T}@4m|r
begin 5TeGdfu @
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' \v{HjqVkC
end QAl4w)F
我们可以直接写成 }2c&ARQ.m>
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere mL#$8wUdt{
2、收缩数据库 /c!^(5K
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--重建索引 (6}7z+
DBCC REINDEX |{,c2Ck:N
DBCC INDEXDEFRAG ZifDU@J$t
--收缩数据和日志 $Dv5TUKw
DBCC SHRINKDB 9`H4"H>yG
DBCC SHRINKFILE OYmutq
3、压缩数据库 ]70ZerQ~L
dbcc shrinkdatabase(dbname) ^,f^YL;
4、转移数据库给新用户以已存在用户权限 ESFJN}Q%0.
exec sp_change_users_login 'update_one','newname','oldname' v/v PU
go .Tw:Y,G
5、检查备份集 V`c,U7[/
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' i>-#QKqJ
6、修复数据库 .>}Z3jUrf
ALTER DATABASE [dvbbs] SET SINGLE_USER #tw_`yh
GO bl10kI:F
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 8aM\B%NGWi
GO p*1B*R
ALTER DATABASE [dvbbs] SET MULTI_USER -M T1q qi
GO sC2NFb-+&
7、日志清除 !N][W#:
SET NOCOUNT ON UbIUc}ge
DECLARE @LogicalFileName sysname, =jxy4`oF
@MaxMinutes INT, @li/Y6Wh
@NewSize INT R7h3O0@!
USE tablename -- 要操作的数据库名 0#m=76[b
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 NP4u/C<
@MaxMinutes = 10, -- Limit on time allowed to wrap log. f1U8 b*F<
@NewSize = 1 -- 你想设定的日志文件的大小(M) A|U0e`Iw
-- Setup / initialize nC?Lz1re
DECLARE @OriginalSize int VT~%);.#
SELECT @OriginalSize = size `]l|YQz\
FROM sysfiles a>d`g
WHERE name = @LogicalFileName oe<@mz/
SELECT 'Original Size of ' + db_name() + ' LOG is ' + X(#8EY}X
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + yVK l%GO
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' *c$UIg
FROM sysfiles AG;KXL[V
WHERE name = @LogicalFileName G-:7,9
CREATE TABLE DummyTrans 23'{{@30
(DummyColumn char (8000) not null) s bR*[2
DECLARE @Counter INT, ofI,[z3
@StartTime DATETIME, V)u#=OS
@TruncLog VARCHAR(255)
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SELECT @StartTime = GETDATE(), SL+n y(y
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' eQ6wEeB9
DBCC SHRINKFILE (@LogicalFileName, @NewSize) XVo+ <&
EXEC (@TruncLog) *.D{d0A
-- Wrap the log if necessary. Z TB6m`
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 0xvSi9
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) %uiCC>cC
AND (@OriginalSize * 8 /1024) > @NewSize ,R7j9#D
BEGIN -- Outer loop. Fo~q35uB
SELECT @Counter = 0 4L97UhLL
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) F~OQ'59!Pf
BEGIN -- update @`^Z5n.4
INSERT DummyTrans VALUES ('Fill Log') *mYGs )|
DELETE DummyTrans -QBM^L
SELECT @Counter = @Counter + 1 ;K4uu<e\
END 6o(.zk`d
EXEC (@TruncLog) /t2H%#v{
END <F-IF7>a
SELECT 'Final Size of ' + db_name() + ' LOG is ' + k;SKQN
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + %503<j
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' B
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FROM sysfiles 4N3O<)C)@
WHERE name = @LogicalFileName k$DRX)e
DROP TABLE DummyTrans *M>~$h7
SET NOCOUNT OFF x'6i9]+r
8、说明:更改某个表 Q]RE,ZZ
exec sp_changeobjectowner 'tablename','dbo' DFRgn
9、存储更改全部表 id`RscV]
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch >f1fvv6
@OldOwner as NVARCHAR(128), `JGW8 _
@NewOwner as NVARCHAR(128) %t74*cX
AS M[-/ &;`f@
DECLARE @Name as NVARCHAR(128) bB*cd!7y
DECLARE @Owner as NVARCHAR(128) uGYH4
DECLARE @OwnerName as NVARCHAR(128) OI6m>XH?
DECLARE curObject CURSOR FOR t!B,%,Dp
select 'Name' = name, ^\\9B-MvY
'Owner' = user_name(uid) =`CK`x
from sysobjects #i.BOQxS
where user_name(uid)=@OldOwner gt~u/Z%
order by name pQ4HX)<P
OPEN curObject ~[BGKqh
FETCH NEXT FROM curObject INTO @Name, @Owner PB BJ.!Pb
WHILE(@@FETCH_STATUS=0) CU*;>h1~u
BEGIN } ,Dk6w$
if @Owner=@OldOwner iex]J@=e
begin {FILt3f;
set @OwnerName = @OldOwner + '.' + rtrim(@Name) G"Ey%Q2K
exec sp_changeobjectowner @OwnerName, @NewOwner J?4dafkw
end
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-- select @name,@NewOwner,@OldOwner Q?`s4P)14o
FETCH NEXT FROM curObject INTO @Name, @Owner D})12qB;u9
END \SYeDy
close curObject .>-D{
deallocate curObject ol
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GO ?UeV5<TewS
10、SQL SERVER中直接循环写入数据 i`iR7UmHeR
declare @i int j*GS')Cm
set @i=1 |}X[Yg=FG
while @i<30 !i@A}$y
begin WK#%G
insert into test (userid) values(@i) Df(+@L5!
set @i=@i+1 SFFJyRCz
end E4_,EeC#
小记存储过程中经常用到的本周,本月,本年函数 L(1} PZ
Dateadd(wk,datediff(wk,0,getdate()),-1) K]dR%j
Dateadd(wk,datediff(wk,0,getdate()),6) M@*Y&(~
Dateadd(mm,datediff(mm,0,getdate()),0) GI:!,9
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) !>kg:xV
Dateadd(yy,datediff(yy,0,getdate()),0) 7lwFxP5QT
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) ) <w`:wD
上面的SQL代码只是一个时间段 U5?QneK
Dateadd(wk,datediff(wk,0,getdate()),-1) &W `7 b<
Dateadd(wk,datediff(wk,0,getdate()),6) ]z#Ita;
就是表示本周时间段. hC]:+.Q+
下面的SQL的条件部分,就是查询时间段在本周范围内的: ;!3: 3;
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) P1$D[aF9$
而在存储过程中 dAM]ZR<
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) (FGHt/!
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) V<ilv<