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。 m<8j' [+
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一、基础 tA#X@HIE
1、说明:创建数据库 s7I*=}{g0.
CREATE DATABASE database-name gK(E0p"
2、说明:删除数据库 C>v
drop database dbname C$*`c6R
3、说明:备份sql server OOl{
--- 创建 备份数据的 device wrqdQ}@(
USE master Redp'rXT<h
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' n/$Bd FH
--- 开始 备份 %T'?7^\>
BACKUP DATABASE pubs TO testBack N#7 ]xL
4、说明:创建新表 /lr RbZ
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) $k'f)E
根据已有的表创建新表: Z6D4VZVF
A:create table tab_new like tab_old (使用旧表创建新表) LvWU
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B:create table tab_new as select col1,col2... from tab_old definition only Xid>8
5、说明:删除新表 yqejd_cd
drop table tabname Jk{>*jYk`
6、说明:增加一个列 ,<EmuEw |
Alter table tabname add column col type d[~c-G6
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。 l06 q1M 3
7、说明:添加主键: Alter table tabname add primary key(col) ykM#EyN
说明:删除主键: Alter table tabname drop primary key(col) v/m`rc]e
8、说明:创建索引:create [unique] index idxname on tabname(col....) '')G6-c/
删除索引:drop index idxname So`xd
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注:索引是不可更改的,想更改必须删除重新建。 T^sxR4F
9、说明:创建视图:create view viewname as select statement <ht>>
删除视图:drop view viewname }\823U
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10、说明:几个简单的基本的sql语句 uFok'3!g7%
选择:select * from table1 where 范围 UD9h5PgT
插入:insert into table1(field1,field2) values(value1,value2) dtF6IdAf
删除:delete from table1 where 范围 ]ei])
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更新:update table1 set field1=value1 where 范围 20fCWVw}?}
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! _I8-0DnOM
排序:select * from table1 order by field1,field2 [desc] [w{ZP4d>
总数:select count as totalcount from table1 vo::y"
求和:select sum(field1) as sumvalue from table1 Rp@u.C<
平均:select avg(field1) as avgvalue from table1 &McmA
最大:select max(field1) as maxvalue from table1 c<H4rB
最小:select min(field1) as minvalue from table1 2sU"p5 j
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11、说明:几个高级查询运算词 Fe= 4^.
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A: UNION 运算符 B"qG-ci
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。 @?1%*/
B: EXCEPT 运算符 ]!A;-m
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。 ^M80 F 7
C: INTERSECT 运算符 /C(L(X
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^bA]l^a
注:使用运算词的几个查询结果行必须是一致的。 NNfCJ|
12、说明:使用外连接 bkM$ Qo
A、left outer join: K&X'^|en
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。 JNu - z:J
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 ;T_9;RU<'b
B:right outer join: c3}}cFe
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。 eT|_0kx1
C:full outer join: a>kDG <.A
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。 ex|kD*=
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二、提升 asF-mf;D
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) [qXpi'q[
法一:select * into b from a where 1<>1 e7qT;
法二:select top 0 * into b from a iY($O/G[+
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) x)?\g{JH
insert into b(a, b, c) select d,e,f from b; ]SPB c
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) Wp]EaYt2D
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 |4c==7.
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. [_0g^(`
4、说明:子查询(表名1:a 表名2:b) [yyV`&
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) |u+&xX7
5、说明:显示文章、提交人和最后回复时间 |H A7 C
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b L,ra=SV F
6、说明:外连接查询(表名1:a 表名2:b) U\
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select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c R#`itIYh
7、说明:在线视图查询(表名1:a ) "5YdmBy
select * from (SELECT a,b,c FROM a) T where t.a > 1;
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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 t#q>U%!
select * from table1 where time between time1 and time2 O7\s1
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select a,b,c, from table1 where a not between 数值1 and 数值2 c]]F`B
9、说明:in 的使用方法 O<3,n;56Z
select * from table1 where a [not] in ('值1','值2','值4','值6') 3dbf!
10、说明:两张关联表,删除主表中已经在副表中没有的信息 "tR.'F[n4P
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ;1dz?'%V
11、说明:四表联查问题: w=`z!x![/
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 ..... ./
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12、说明:日程安排提前五分钟提醒 m=9N^_
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 wgyO%
13、说明:一条sql 语句搞定数据库分页 !BX62j\?
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 TH|hrL;:8
14、说明:前10条记录 sfV.X:ev
select top 10 * form table1 where 范围 X\x9CA
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.) 2{CSH_"Z7
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) @5wg' mM
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 V\ "5<>+O
(select a from tableA ) except (select a from tableB) except (select a from tableC) /RM-+D:Y
17、说明:随机取出10条数据 @r ?`:&m0
select top 10 * from tablename order by newid() Q8x{V_Pot
18、说明:随机选择记录 4I*Mc%dD
select newid() ~Z2eQx
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19、说明:删除重复记录 P1wRt5
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) @"8QG^q8de
20、说明:列出数据库里所有的表名 ? st#6=M
select name from sysobjects where type='U' {wP|b@(1t
21、说明:列出表里的所有的 gcxk'd
select name from syscolumns where id=object_id('TableName') 'EV *-_k
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。 @>5<m'}2
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 lc-|Q#$3$
显示结果: pCc7T-"og
type vender pcs V+24- QWh
电脑 A 1 .Qt3!ek
电脑 A 1 a1SOC=.M;
光盘 B 2 k_>{"Rc
光盘 A 2 cEdJn@ ,
手机 B 3 pXv[]v
手机 C 3 j\f$r,4
23、说明:初始化表table1 fZ}Y(TG/
TRUNCATE TABLE table1 3\r@f_p
24、说明:选择从10到15的记录 df*#?Ok
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Qiw4'xQm
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三、技巧 `HG19_Z
1、1=1,1=2的使用,在SQL语句组合时用的较多 5iddB $
"where 1=1" 是表示选择全部 "where 1=2"全部不选, ==1/N{{R
如: \!Zh= "hN
if @strWhere !='' 2?iOB6
begin WG
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere q_y,j&
end ]A$^ l,
else 7/_ VE
begin :ZS8Zm"
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 3C=clB9<
end 9jGuelwN
我们可以直接写成 Sn2Ds)Pfx3
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 07Q[L'}y@
2、收缩数据库 AH'4H."o/9
--重建索引 yI.H4Dl<
DBCC REINDEX |vN@2h(|"
DBCC INDEXDEFRAG t"/"Ge#a
--收缩数据和日志 b+].Uc
DBCC SHRINKDB ~}-p5 q2
DBCC SHRINKFILE V/}>>4
3、压缩数据库 8@yc}~8 *
dbcc shrinkdatabase(dbname) 8V|jL?a~
4、转移数据库给新用户以已存在用户权限 _:X|R#d
exec sp_change_users_login 'update_one','newname','oldname' 8;g.3Qv
go I49l2>
5、检查备份集 9LO.8Jy
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' M1]6lg[si
6、修复数据库 }SMJD
ALTER DATABASE [dvbbs] SET SINGLE_USER 'SU9NQS
GO O%K?l}e
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 7s8<FyFsjd
GO bI]UO)
ALTER DATABASE [dvbbs] SET MULTI_USER ?3,64[
GO Uk*;C
7、日志清除 U++~3e@l
SET NOCOUNT ON T]#,R|)d
DECLARE @LogicalFileName sysname, dD^_^'i
@MaxMinutes INT, _A,-[*OKI
@NewSize INT lii]4k+z
USE tablename -- 要操作的数据库名 m-'(27
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 AO}i@YJth
@MaxMinutes = 10, -- Limit on time allowed to wrap log. B2G5hbaA
@NewSize = 1 -- 你想设定的日志文件的大小(M)
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-- Setup / initialize }.MoDR3\
DECLARE @OriginalSize int d@6:|auO
SELECT @OriginalSize = size 827)n[#%|
FROM sysfiles Jn[q<e"
WHERE name = @LogicalFileName g/l0}%
SELECT 'Original Size of ' + db_name() + ' LOG is ' + n-y^7'v
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ? gA=39[j
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' WE 5"A|
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FROM sysfiles u3M`'YCb
WHERE name = @LogicalFileName LZQFj/,Jg
CREATE TABLE DummyTrans i_0,BVC
(DummyColumn char (8000) not null) :!I)r$
DECLARE @Counter INT, hnsa)@
@StartTime DATETIME, =nvAOvP{?
@TruncLog VARCHAR(255) Q.9Ph
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SELECT @StartTime = GETDATE(), ayH%
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@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' x0u?*5-t
DBCC SHRINKFILE (@LogicalFileName, @NewSize) Qh|-a@
EXEC (@TruncLog) ^p"4)6p-W
-- Wrap the log if necessary. q!hy;K`Jd
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired jMf 7J
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) !bZhj3.
AND (@OriginalSize * 8 /1024) > @NewSize A]Q1&qM%
BEGIN -- Outer loop. PTzp;.
SELECT @Counter = 0 .*EOVo9S
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) {+C %D'
BEGIN -- update ^_*jp[!`b$
INSERT DummyTrans VALUES ('Fill Log') r,u<y_YW
DELETE DummyTrans vh|Tb5W<
SELECT @Counter = @Counter + 1 *Z]5!$UpC
END 'R4>CZ%jV
EXEC (@TruncLog) RwAbIXG{0
END _.d}lK3$2
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ]RH=s7L
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + ;Cr_NP[8|j
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' `ICcaRIN8I
FROM sysfiles kyW6S+ #-
WHERE name = @LogicalFileName HA^jk%53
DROP TABLE DummyTrans * ?
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SET NOCOUNT OFF (orrX Ez
8、说明:更改某个表 6keP':bt
exec sp_changeobjectowner 'tablename','dbo' '2|1%NSW9
9、存储更改全部表 {B FT
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch H$~M`Y9I~
@OldOwner as NVARCHAR(128), [2GXAvXsT
@NewOwner as NVARCHAR(128) j+_S$T8w
AS a.
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DECLARE @Name as NVARCHAR(128) =cf{f]N
DECLARE @Owner as NVARCHAR(128) )"(V*Z
DECLARE @OwnerName as NVARCHAR(128) ./ "mn3U
DECLARE curObject CURSOR FOR Bii6Z@kS
select 'Name' = name, KWFyw>*)
'Owner' = user_name(uid) KY4d+~2
from sysobjects Dk)@>l:gI,
where user_name(uid)=@OldOwner Z|2Eb*
order by name )^t!|*1LA
OPEN curObject xGKfej9
FETCH NEXT FROM curObject INTO @Name, @Owner Bz~ -2#l
WHILE(@@FETCH_STATUS=0) -M"IVyy@
BEGIN wl7 M fyU
if @Owner=@OldOwner OOCQsoN
begin )-0[ra]
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 7d3'CQQ4
exec sp_changeobjectowner @OwnerName, @NewOwner HzP.aw4
end \Os:6U=X-
-- select @name,@NewOwner,@OldOwner EKcC+g
FETCH NEXT FROM curObject INTO @Name, @Owner ^Vag1(hdq
END j.k@6[R>?
close curObject F|ETug
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deallocate curObject .W!tveX8-
GO *Y8XP8u/
10、SQL SERVER中直接循环写入数据 iPMB$SdfO
declare @i int %/P=m-K
set @i=1 66oK3%[
while @i<30 M[A-1]'
begin |}Q( F+cL
insert into test (userid) values(@i) 2*+3RrJ
set @i=@i+1 '4$lL6ly>
end F
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小记存储过程中经常用到的本周,本月,本年函数 /
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Dateadd(wk,datediff(wk,0,getdate()),-1) aw1P5aPmX
Dateadd(wk,datediff(wk,0,getdate()),6) Was'A+GZ
Dateadd(mm,datediff(mm,0,getdate()),0) 1XG$ z@NN
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) "hW(S
Dateadd(yy,datediff(yy,0,getdate()),0) ~NxEc8Y
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) KL
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上面的SQL代码只是一个时间段 3Q",9(D
Dateadd(wk,datediff(wk,0,getdate()),-1) G OpjRA@
Dateadd(wk,datediff(wk,0,getdate()),6) &(g|="T
就是表示本周时间段. QW2?n`Fa9-
下面的SQL的条件部分,就是查询时间段在本周范围内的: P2Onkl
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) q&Q/?g>f
而在存储过程中 7UnzIe
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 9X3yp:>V
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) oB4#J*