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。 #N}}8RL
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一、基础 g c=|<(
1、说明:创建数据库 -3U}
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CREATE DATABASE database-name 7B"aFnK;[J
2、说明:删除数据库 )W JI=jl
drop database dbname $:Zxb
3、说明:备份sql server lfd{O7 L0b
--- 创建 备份数据的 device Ap18qp
USE master 3PeJPw
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' |]b/5s;>
--- 开始 备份 8so}^2hTlT
BACKUP DATABASE pubs TO testBack q`zR 6
4、说明:创建新表 wb"t:(>&
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) {z
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根据已有的表创建新表: n :kxG
A:create table tab_new like tab_old (使用旧表创建新表) ~36XJ
B:create table tab_new as select col1,col2... from tab_old definition only <QLj6#d7Y
5、说明:删除新表 )@M|YM1+
drop table tabname RM$S|y{L
6、说明:增加一个列 me\)JCZpb{
Alter table tabname add column col type n:z>l,`C]
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。 ?KW?] o
7、说明:添加主键: Alter table tabname add primary key(col) s5#g[}dj
说明:删除主键: Alter table tabname drop primary key(col) sRI8znus
8、说明:创建索引:create [unique] index idxname on tabname(col....) cu|q&
删除索引:drop index idxname 'Q,<_L"
注:索引是不可更改的,想更改必须删除重新建。 8Wp1L0$B
9、说明:创建视图:create view viewname as select statement `o'sp9_3
删除视图:drop view viewname nwH|Hs riU
10、说明:几个简单的基本的sql语句 [/]3:|
选择:select * from table1 where 范围 !Xce iQu
插入:insert into table1(field1,field2) values(value1,value2) f2f$aZ
删除:delete from table1 where 范围 jZyh
更新:update table1 set field1=value1 where 范围 )A;<'{t #L
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! f89<o#bm7h
排序:select * from table1 order by field1,field2 [desc] 36UWoo
总数:select count as totalcount from table1 Yy 1Pipv
求和:select sum(field1) as sumvalue from table1 ||NCVGJG
平均:select avg(field1) as avgvalue from table1 u{G6xuPWf
最大:select max(field1) as maxvalue from table1 '11h Iu=:
最小:select min(field1) as minvalue from table1 THZ3%o=X
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11、说明:几个高级查询运算词 [-a/]
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A: UNION 运算符 oWOZ0]H1
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。 Zwl?*t\D
B: EXCEPT 运算符 tF(mD=[
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。 yB[LO(i
C: INTERSECT 运算符 AP@d2{"m}
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。 ]"_'o~
注:使用运算词的几个查询结果行必须是一致的。 |V]E8Qt
12、说明:使用外连接 f}3bYF
A、left outer join: dq&d>f1
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。 GrIdQi^8
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 _:
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B:right outer join: e&nw&9vo
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。 VNPdL
C:full outer join: _95tgJ y
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。 9rz "@LM
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二、提升 ](pD<FfS]'
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) h~t]WN
法一:select * into b from a where 1<>1 B[h9epU]K
法二:select top 0 * into b from a E>v~B;@
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) y0^FTSQ|
insert into b(a, b, c) select d,e,f from b; ~46ed3eGzi
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) HN%ZN}
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 k5M(Ve
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. nK$m:=
4、说明:子查询(表名1:a 表名2:b) e{/\znBS%
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) Joj8'
5、说明:显示文章、提交人和最后回复时间 Zx0c6d!B
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 4mg&H0 !
6、说明:外连接查询(表名1:a 表名2:b) S/aPYrk>6
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c l.!
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7、说明:在线视图查询(表名1:a ) Oylw,*%
select * from (SELECT a,b,c FROM a) T where t.a > 1; 2(|V1]6D?
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 I+SL0
select * from table1 where time between time1 and time2 ^&%?Q_]
select a,b,c, from table1 where a not between 数值1 and 数值2 iV=#'yY
9、说明:in 的使用方法 c$;enAf@
select * from table1 where a [not] in ('值1','值2','值4','值6') "G:>}cs%?
10、说明:两张关联表,删除主表中已经在副表中没有的信息 b%F*N r
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) x&wUPo{
11、说明:四表联查问题: !bg3
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 ..... ~@bKQ>Xw
12、说明:日程安排提前五分钟提醒 @VAhmYz
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 Qzv_|U
13、说明:一条sql 语句搞定数据库分页 +Oa1FvoEA
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 7Ll(,i<,C
14、说明:前10条记录 2UquN0
select top 10 * form table1 where 范围 B HYEd}M
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.) 2o;M:+KQ)
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) umeb&\:8S-
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 Oh: -Y]m=
(select a from tableA ) except (select a from tableB) except (select a from tableC) %;S5_K,
17、说明:随机取出10条数据 gg9W7%t/
select top 10 * from tablename order by newid() }sZ]SE
18、说明:随机选择记录 -XBNtM_"
select newid() t30V_`eQ
19、说明:删除重复记录 A(B2XBS!?
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) t Ks0]8tc
20、说明:列出数据库里所有的表名 HT'dft #
select name from sysobjects where type='U' O<*iDd`(e
21、说明:列出表里的所有的 (;h\)B!o
select name from syscolumns where id=object_id('TableName') K!X8KPo
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。 o2L/8q.
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 QX4I+x~oo\
显示结果: }m?L/Y'}
type vender pcs &nYmVwi?"Q
电脑 A 1 )mU)7@!
电脑 A 1 ?/~1z*XUW
光盘 B 2 4^5s\f B
光盘 A 2 {+MMqJCa
手机 B 3 RK0IkRXQd
手机 C 3 ,LvJ'N
23、说明:初始化表table1 @`yfft
TRUNCATE TABLE table1 jZGmTtx
24、说明:选择从10到15的记录 9}-,dgAB
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc +qdK]RR}
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三、技巧 $f%_ 4 =
1、1=1,1=2的使用,在SQL语句组合时用的较多 03xQ%"TU<
"where 1=1" 是表示选择全部 "where 1=2"全部不选, x]:mc%4-Z
如: 4_ 3\4
if @strWhere !='' G2rvi=8=
begin = FQH
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere k"6^gup(U
end S}+n\pyQ
else LX8vVj8K
begin ~(c<ioIf
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' "o1/gV
end Msf yIB
我们可以直接写成 zy.Ok 49
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere :V
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2、收缩数据库 X qh+
--重建索引 [|3
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DBCC REINDEX v1:5r
DBCC INDEXDEFRAG pD{Li\LY
--收缩数据和日志 1+]e?
DBCC SHRINKDB Vj_
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DBCC SHRINKFILE ,70|I{,Km
3、压缩数据库 .R1)i-^
dbcc shrinkdatabase(dbname) uZNR]+Yu@
4、转移数据库给新用户以已存在用户权限 OG.`\G|
exec sp_change_users_login 'update_one','newname','oldname' s=q}XIWK
go +um;
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5、检查备份集 82$^pg>
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 607#d):Y
6、修复数据库 J&5|'yVX
ALTER DATABASE [dvbbs] SET SINGLE_USER 0-@waK
GO Z^sO`C
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK wL*z+>5
GO .{6TX"M
ALTER DATABASE [dvbbs] SET MULTI_USER iU &V}p
GO :%Bo)0a9
7、日志清除 X(8]9
SET NOCOUNT ON 2/GH5b(
DECLARE @LogicalFileName sysname, tqHXzmsjW
@MaxMinutes INT, niFjsTA.Z
@NewSize INT >0> M@s
USE tablename -- 要操作的数据库名 -n6C~Yx
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 Yd@9P2C
@MaxMinutes = 10, -- Limit on time allowed to wrap log. nX
@NewSize = 1 -- 你想设定的日志文件的大小(M) -Iq#h)Q*
-- Setup / initialize twJck~l~n
DECLARE @OriginalSize int Ys\l[$_`*
SELECT @OriginalSize = size ,[A} 86
FROM sysfiles JO
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WHERE name = @LogicalFileName % R'eV<
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 3vy5JTCz~
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + %j=7e@
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' _onHe"%{
FROM sysfiles pgI@[zp7
WHERE name = @LogicalFileName sg3%n0Ms.W
CREATE TABLE DummyTrans NY_Oo!)3
(DummyColumn char (8000) not null) {r Gx*<e
DECLARE @Counter INT, !a0HF p$9
@StartTime DATETIME, ioZ2J"s
@TruncLog VARCHAR(255) W?.Y%wc0
SELECT @StartTime = GETDATE(), }JI5,d
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' LnBkd:>}
DBCC SHRINKFILE (@LogicalFileName, @NewSize) p0-\G6
EXEC (@TruncLog) qoEOM%dAqV
-- Wrap the log if necessary. >~6
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired <{'':/tXI
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName)
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AND (@OriginalSize * 8 /1024) > @NewSize YyI|^f8C
BEGIN -- Outer loop. BKN]DxJ6
SELECT @Counter = 0 ;Eck7nRA)
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) t]Vw`z%G
BEGIN -- update
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INSERT DummyTrans VALUES ('Fill Log') B64%|
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DELETE DummyTrans ek.L(n,J|
SELECT @Counter = @Counter + 1 ~ejHA~QC
END Bs^W0K$uBO
EXEC (@TruncLog) 7%aB>uA
END :qI myaGQ
SELECT 'Final Size of ' + db_name() + ' LOG is ' + py)V7*CgH
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + pxP7yJL`
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' @#sQ7eMoy
FROM sysfiles keX0br7u_
WHERE name = @LogicalFileName \&SP7~-eq
DROP TABLE DummyTrans M5D,YC3<
SET NOCOUNT OFF 6MZfoR
8、说明:更改某个表 vq x;FAqZ
exec sp_changeobjectowner 'tablename','dbo' iE$0-Qe[3
9、存储更改全部表 $)kIYM&
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch gp;(M~we
@OldOwner as NVARCHAR(128), nPKf~|\1{
@NewOwner as NVARCHAR(128) <;=X7l+
AS X\M0Q%8
DECLARE @Name as NVARCHAR(128) #B54p@.}
DECLARE @Owner as NVARCHAR(128) F> ..eK
DECLARE @OwnerName as NVARCHAR(128) puDy&T
DECLARE curObject CURSOR FOR rGx1>xd(k
select 'Name' = name, $+$+;1[
'Owner' = user_name(uid) sjztT<{Q^-
from sysobjects GX(p7ZgB2
where user_name(uid)=@OldOwner E-l>z%
order by name 9erTb?@S
OPEN curObject HAP9XC(F]
FETCH NEXT FROM curObject INTO @Name, @Owner O75ioO0
WHILE(@@FETCH_STATUS=0) D*heYh
BEGIN {R&F_51)V
if @Owner=@OldOwner e-x{7
begin V[CS{Hy'
set @OwnerName = @OldOwner + '.' + rtrim(@Name) he
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exec sp_changeobjectowner @OwnerName, @NewOwner k4eV*e8
end Rg+V;C
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-- select @name,@NewOwner,@OldOwner xqLLoSte
FETCH NEXT FROM curObject INTO @Name, @Owner GQT|T0>Ro
END J1g
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close curObject 4uD!-1LT@
deallocate curObject Zb3E-'G+
GO ln9U>*<
10、SQL SERVER中直接循环写入数据 DOf[? vbu
declare @i int !Il<'+ ^
set @i=1 $7,n8ddRy
while @i<30 ZCV&v47\p_
begin c[ga@Vy
insert into test (userid) values(@i) ~u7a50
set @i=@i+1 9CW .xX8
end .DIHd/wA
小记存储过程中经常用到的本周,本月,本年函数 H2[S]`?
Dateadd(wk,datediff(wk,0,getdate()),-1) `2 Z
Dateadd(wk,datediff(wk,0,getdate()),6) Q_]O[Kx
Dateadd(mm,datediff(mm,0,getdate()),0) jg' 'T1)
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) dfO84Z}
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Dateadd(yy,datediff(yy,0,getdate()),0) %5$yz| :
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 8q}`4wCD$
上面的SQL代码只是一个时间段 <{:$]3
Dateadd(wk,datediff(wk,0,getdate()),-1) @>&UoH}2
Dateadd(wk,datediff(wk,0,getdate()),6) d8e6}C2v
就是表示本周时间段. KTd4pW?w
下面的SQL的条件部分,就是查询时间段在本周范围内的: C {gYrz)
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) Vtr0=-m&
而在存储过程中 8+Oyhd*|
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) r>A,7{
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) KGFmC[