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。 cAogz/<S
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一、基础 QS4sSua
1、说明:创建数据库 !vHnMY~AG
CREATE DATABASE database-name <=l!~~%
2、说明:删除数据库 qH: `
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drop database dbname \f}S Hh
3、说明:备份sql server &HNJ'
--- 创建 备份数据的 device wWKC.N
USE master ><mZOTn e;
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' TxoMCN?7c
--- 开始 备份 be |k"s|6)
BACKUP DATABASE pubs TO testBack xa[<k>r3
4、说明:创建新表 $6Lgaz
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) &.y:QVR,!
根据已有的表创建新表: BuCU_/H
A:create table tab_new like tab_old (使用旧表创建新表) MMqkNe
B:create table tab_new as select col1,col2... from tab_old definition only rUvqAfE&+
5、说明:删除新表 Xp[[ xV|
drop table tabname eu@-v"=w
6、说明:增加一个列 gLa#y
Alter table tabname add column col type d+[yW7%J
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 Cg?D<l4
7、说明:添加主键: Alter table tabname add primary key(col) #'^!@+)
说明:删除主键: Alter table tabname drop primary key(col) Oz#$x
8、说明:创建索引:create [unique] index idxname on tabname(col....) 3;zJ\a.+
删除索引:drop index idxname
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注:索引是不可更改的,想更改必须删除重新建。 Og4 X3QG
9、说明:创建视图:create view viewname as select statement DN2K4%cM%'
删除视图:drop view viewname y\$B9KX
10、说明:几个简单的基本的sql语句 5)+(McJC
选择:select * from table1 where 范围 `Rub"zM
插入:insert into table1(field1,field2) values(value1,value2) )mz [2Sfg
删除:delete from table1 where 范围 d kHcG&)
更新:update table1 set field1=value1 where 范围 0?qXD O&~
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! gbL99MZ@~
排序:select * from table1 order by field1,field2 [desc] #oSQWC=T
总数:select count as totalcount from table1 bHH{bv~Z
求和:select sum(field1) as sumvalue from table1 *6sB$E_y
平均:select avg(field1) as avgvalue from table1 "
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最大:select max(field1) as maxvalue from table1 !@{_Qt1
最小:select min(field1) as minvalue from table1 ^>gRK*,
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11、说明:几个高级查询运算词 &?IOrHSv!
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A: UNION 运算符 ~aQ>DpSEf
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 6a[D]46y,2
B: EXCEPT 运算符 VO] Jvf
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 Q^$IlzG7i
C: INTERSECT 运算符 y44FejH(v
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。 RIJ+]uir4
注:使用运算词的几个查询结果行必须是一致的。 $v#Q'?jE
12、说明:使用外连接 JR|yg=E
A、left outer join: D|/Azy.[
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 A)Wp W M
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 2+M(!FHfy
B:right outer join: -l+&Bkf
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 VI,z7
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C:full outer join: C18pK8-
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 y:WRpCZoa
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二、提升 ](a*R
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) <?kr"[cQeP
法一:select * into b from a where 1<>1 HK)$ls
法二:select top 0 * into b from a W?mn8Y;{`
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) QMea2q|3$
insert into b(a, b, c) select d,e,f from b; gRIRc4p
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) izsAn"v
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 lBqu}88q0
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. \~UyfVPRT
4、说明:子查询(表名1:a 表名2:b) oe_l:Y%
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) qUA&XUJ
5、说明:显示文章、提交人和最后回复时间 VJJGTkm
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b
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6、说明:外连接查询(表名1:a 表名2:b) BoYWx^VHx^
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Q%KH^<
7、说明:在线视图查询(表名1:a ) rVd (H
select * from (SELECT a,b,c FROM a) T where t.a > 1; 7m_Jb5
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 ;Xg6'yxJ
select * from table1 where time between time1 and time2 G,9osTt/
select a,b,c, from table1 where a not between 数值1 and 数值2 4SCb9|/Q
9、说明:in 的使用方法 A(X~pP&oF
select * from table1 where a [not] in ('值1','值2','值4','值6') 5<w"iqZ\?N
10、说明:两张关联表,删除主表中已经在副表中没有的信息 hV#+joT8i
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) <Z{\3X^
11、说明:四表联查问题: ]IMBRZQqb
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 ..... fqZqPcT0
12、说明:日程安排提前五分钟提醒 y K)7%j!
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 3GUO
13、说明:一条sql 语句搞定数据库分页 AX}l~
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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 zk=5uKcPE
14、说明:前10条记录 9#{?*c6
select top 10 * form table1 where 范围 gm~Ka%O|F
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.) NX&mEz
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) km,}7^?F0r
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 8.HqQ:?&2t
(select a from tableA ) except (select a from tableB) except (select a from tableC) L3lf2 8W
17、说明:随机取出10条数据 G 5w:
select top 10 * from tablename order by newid() QE[ETv
18、说明:随机选择记录 | V Ps5
select newid() '<5Gf1 @|
19、说明:删除重复记录 z #c)Q
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) %>`0hk88
20、说明:列出数据库里所有的表名 Os'
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select name from sysobjects where type='U' P9;
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21、说明:列出表里的所有的 Lo
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select name from syscolumns where id=object_id('TableName') KArt4+31
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。 D@*<p h=
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 W4Rs9NA}
显示结果: ; S7
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type vender pcs Uq `B#JI
电脑 A 1 5BR9f3}
电脑 A 1 fC+<n{"C
光盘 B 2 ,!_$A}@0
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光盘 A 2 M@EML
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手机 B 3 QyQ&xgS
手机 C 3 <iVn!P
23、说明:初始化表table1 fiqeXE?E
TRUNCATE TABLE table1 U1G"T(;s:
24、说明:选择从10到15的记录 u!?cKZw
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 5xX*68]%
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三、技巧 wZ/Zc}
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1、1=1,1=2的使用,在SQL语句组合时用的较多 zY_BnJ^
"where 1=1" 是表示选择全部 "where 1=2"全部不选, E7@0,9AU
如: lgFA}p@
if @strWhere !='' q|BR-0yi
begin C-'n4AY^
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ;4p_lw@
end Bpt%\LK\~O
else Pd9qY
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begin {j O:9O@
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 'MH WNPG0
end d?^bCf+<
我们可以直接写成 {eA0I\c(C
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere @T[}]e
2、收缩数据库 aal5d_Y
--重建索引 aF1i!Z
DBCC REINDEX !PJD+SrG
DBCC INDEXDEFRAG kbS+3#+
--收缩数据和日志 INqD(EG
DBCC SHRINKDB ZZk6 @C
DBCC SHRINKFILE BS*IrH
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3、压缩数据库 [F{q.mZj
dbcc shrinkdatabase(dbname) $\?BAkx
4、转移数据库给新用户以已存在用户权限 ew
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exec sp_change_users_login 'update_one','newname','oldname' Y1? wf.
go NF+^
5、检查备份集 It>8XKS
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' F33&A<(,
6、修复数据库 ={ P
ALTER DATABASE [dvbbs] SET SINGLE_USER 78&(>8@m
GO 5/4N Y
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK N9 @@n:JT
GO uLXMEx<^
ALTER DATABASE [dvbbs] SET MULTI_USER ^x(BZolkm
GO E-jL"H*
7、日志清除 V("@z<b|
SET NOCOUNT ON gFlUMfKh
DECLARE @LogicalFileName sysname, `Mx&,;x
@MaxMinutes INT, at"-X ?`d
@NewSize INT e]F4w(*=
USE tablename -- 要操作的数据库名 A (z
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SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 t@(S=i7}-
@MaxMinutes = 10, -- Limit on time allowed to wrap log. 3>;zk#b2
@NewSize = 1 -- 你想设定的日志文件的大小(M) MQ7d IUs
-- Setup / initialize bso l>M[<
DECLARE @OriginalSize int
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SELECT @OriginalSize = size x[l_dmq
FROM sysfiles .:gZ*ks~
WHERE name = @LogicalFileName 6\"g,f
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 9>,$q"M}?
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + Y&M}3H>E
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' fui;F"+1
FROM sysfiles {jB& e,
WHERE name = @LogicalFileName ajB4Lj,:r
CREATE TABLE DummyTrans ? t<yk(q
(DummyColumn char (8000) not null) d$.t0-lC
DECLARE @Counter INT, ;s{k32e
@StartTime DATETIME, ~nO]R
@TruncLog VARCHAR(255) %6Wv-:LY
SELECT @StartTime = GETDATE(), O6JH )Ka"S
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' j"g[qF/*
DBCC SHRINKFILE (@LogicalFileName, @NewSize) NKyaR_q`
EXEC (@TruncLog) O#Y;s;)i"
-- Wrap the log if necessary.
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired :: IAXGH)
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) S5B12P
AND (@OriginalSize * 8 /1024) > @NewSize i2$7nSQ9
BEGIN -- Outer loop. x?T.ItW:K
SELECT @Counter = 0 n?uVq6c
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) L[v-5u)
BEGIN -- update nO-1^HUl
INSERT DummyTrans VALUES ('Fill Log') $&IF#uDf
DELETE DummyTrans ]6JI((
SELECT @Counter = @Counter + 1 JBzRL"|
END S
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EXEC (@TruncLog) xZ2^lsY
END ~Q<h,P
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ?+6w8j%\
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + }EFMJ,NQ
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ^|Bpo(
FROM sysfiles e'%"G{(D
WHERE name = @LogicalFileName PEA<H0
DROP TABLE DummyTrans _19x`J3
SET NOCOUNT OFF j;%RV)e
8、说明:更改某个表 ;&="aD
exec sp_changeobjectowner 'tablename','dbo' )X-~+X91S
9、存储更改全部表 Iu(j"b#
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch eYSVAj
@OldOwner as NVARCHAR(128), 79}voDFd
@NewOwner as NVARCHAR(128) Z?@1X`@
AS ::'DWD1
DECLARE @Name as NVARCHAR(128) %A 4F?/E
DECLARE @Owner as NVARCHAR(128) +-8u09-F
DECLARE @OwnerName as NVARCHAR(128) gN"Abc
DECLARE curObject CURSOR FOR `2}H$D
select 'Name' = name, /m#!<t7
'Owner' = user_name(uid) 9hoTxWpmy
from sysobjects g$=y#<2?
where user_name(uid)=@OldOwner *c"tW8uR
order by name 2oL~N*^C
OPEN curObject B^8]quOH
FETCH NEXT FROM curObject INTO @Name, @Owner y9<]F6TT
WHILE(@@FETCH_STATUS=0) <$m=@@qg
BEGIN HI+87f_Q
if @Owner=@OldOwner c{7<z9U
begin .Y@)3
set @OwnerName = @OldOwner + '.' + rtrim(@Name) w?u4-GT
exec sp_changeobjectowner @OwnerName, @NewOwner H~fX>6>
end mC-'z
-- select @name,@NewOwner,@OldOwner G3 h&nH,>
FETCH NEXT FROM curObject INTO @Name, @Owner #f*,mY|>
END 0LQ|J(u
close curObject Z?XgY\(a(Q
deallocate curObject k2]Q~
GO u+
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10、SQL SERVER中直接循环写入数据 Xgq-r $O2X
declare @i int "l83O8 L
set @i=1 2y_R05O0
while @i<30 M{sn{
begin Ojea~Y]Sr
insert into test (userid) values(@i) |[%CFm}+?
set @i=@i+1 Glz yFj
end MSef2|"P#
小记存储过程中经常用到的本周,本月,本年函数 .Ioj]r
Dateadd(wk,datediff(wk,0,getdate()),-1) UXU!sd
Dateadd(wk,datediff(wk,0,getdate()),6) (t^&L
Dateadd(mm,datediff(mm,0,getdate()),0) !%v=9muay
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) 6x6xv:\
Dateadd(yy,datediff(yy,0,getdate()),0) X?3?R\/
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) oh>X/uj
上面的SQL代码只是一个时间段 DM*GvBdR
Dateadd(wk,datediff(wk,0,getdate()),-1) nMz~.^Q-
Dateadd(wk,datediff(wk,0,getdate()),6) %Fb4
就是表示本周时间段. kaKV{;UM
下面的SQL的条件部分,就是查询时间段在本周范围内的: [ij8h,[~]
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) _dg2i|yP<
而在存储过程中 +a@:?=hc
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) *ud"?{)Z
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) lQt&K1m