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。 I")mg~f
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一、基础 f67t.6Vw2+
1、说明:创建数据库 Su<>UsdUC
CREATE DATABASE database-name VdGpreRPC
2、说明:删除数据库 [4+I1UR`
drop database dbname xEufbFAN?
3、说明:备份sql server b`;Cm)@X!)
--- 创建 备份数据的 device HTSk40V
USE master m@YK8c#$
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' !PgwFJ
--- 开始 备份 hJ75(I
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BACKUP DATABASE pubs TO testBack 5+t$4N+P
4、说明:创建新表 #!P>.".
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) (/ -90u
根据已有的表创建新表: sYB2{w
A:create table tab_new like tab_old (使用旧表创建新表) Dn`
B:create table tab_new as select col1,col2... from tab_old definition only z~ua#(z1S
5、说明:删除新表 V14+?L
drop table tabname PgsG*5WQ
6、说明:增加一个列 2_TFc2d
Alter table tabname add column col type H!|g?"C
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 aJ[|80U
7、说明:添加主键: Alter table tabname add primary key(col) |3>%(4
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说明:删除主键: Alter table tabname drop primary key(col) rx@2Dmt6
8、说明:创建索引:create [unique] index idxname on tabname(col....) 4jzjrG
删除索引:drop index idxname ei~f1$zc#h
注:索引是不可更改的,想更改必须删除重新建。 BW ux!
9、说明:创建视图:create view viewname as select statement w17CZa
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删除视图:drop view viewname Nnfq!%
10、说明:几个简单的基本的sql语句 N(P2Lo{JF
选择:select * from table1 where 范围 GE=PaYz
插入:insert into table1(field1,field2) values(value1,value2) >[Tt'.S!?
删除:delete from table1 where 范围 RL*b47,
更新:update table1 set field1=value1 where 范围 wM}AWmH
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! gP>W* ]0r1
排序:select * from table1 order by field1,field2 [desc] [rz5tfMp
总数:select count as totalcount from table1 YUTI)&y
求和:select sum(field1) as sumvalue from table1 AB<%GzW0(
平均:select avg(field1) as avgvalue from table1 NHe[,nIV
最大:select max(field1) as maxvalue from table1 3CPSyF
最小:select min(field1) as minvalue from table1 Hxn#vAc
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11、说明:几个高级查询运算词 ]1MZ:]k
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A: UNION 运算符 1?G%&X@
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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。 lUw=YM
B: EXCEPT 运算符 4~2 9,
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。 t_+owiF)M
C: INTERSECT 运算符 &w:0ad|
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。 3mL(xpT.8z
注:使用运算词的几个查询结果行必须是一致的。 lHE \Z`
12、说明:使用外连接 -?-yeJP2
A、left outer join: \y+^r|IL
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。 WP'.o
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 "`h.8=-
B:right outer join: COj^pdE3
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。 >O0<u
C:full outer join: ,[3}t%Da
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。 fP 3t0cp
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二、提升 f`8?]@y{
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) /v.<h*hxWy
法一:select * into b from a where 1<>1 GGUwS
法二:select top 0 * into b from a +jO#?J
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ! vuun |
insert into b(a, b, c) select d,e,f from b; 6XnUs1O
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) o\fPZ`p-m~
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 #}Bv/`t
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. ;@O8y\@
4、说明:子查询(表名1:a 表名2:b) <RcB: h
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) '@5x=>
5、说明:显示文章、提交人和最后回复时间 1B$8<NCQ=?
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b mRN[lj
6、说明:外连接查询(表名1:a 表名2:b) tg<bVA)E'J
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c \\C!{}+
7、说明:在线视图查询(表名1:a ) U*XdFH}vV
select * from (SELECT a,b,c FROM a) T where t.a > 1; |W*2L]&
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 j$4lyDfD
select * from table1 where time between time1 and time2 *%%n9T
select a,b,c, from table1 where a not between 数值1 and 数值2 yM7FR);
9、说明:in 的使用方法 "]q0|ZdOwH
select * from table1 where a [not] in ('值1','值2','值4','值6') z? GtC{L9
10、说明:两张关联表,删除主表中已经在副表中没有的信息 'a$/ !~X
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) |)mUO:*
11、说明:四表联查问题: M0hR]4T
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 ..... g!i45]6[Nw
12、说明:日程安排提前五分钟提醒 Z%
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SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 w^:@g~
13、说明:一条sql 语句搞定数据库分页 ~+PK Ws'}F
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 QBA{*@ A-
14、说明:前10条记录 iz+,,UH
select top 10 * form table1 where 范围 }4Q3S1|U
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.) X @/X65=[
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) Z1p%6f`
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 w9Nk8OsL
(select a from tableA ) except (select a from tableB) except (select a from tableC) &SPIu,
17、说明:随机取出10条数据 M
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select top 10 * from tablename order by newid() pV1;gqXNS
18、说明:随机选择记录 SQN{/")T
select newid() <~e*YrJ?-
19、说明:删除重复记录 5f75r
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) 2o7o~r
20、说明:列出数据库里所有的表名 BF"eVKA
select name from sysobjects where type='U' %Rf{v5
21、说明:列出表里的所有的 u3DFgl3-7
select name from syscolumns where id=object_id('TableName') g@]1H41
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
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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 BWr!K5w>i
显示结果: 4$4Tx9C
type vender pcs S+?*l4QK
电脑 A 1 fT=ZiHJ3Gu
电脑 A 1 I/gfsyfA
光盘 B 2 W k "_lJ
光盘 A 2 |aj]]l[@S
手机 B 3 )=5*iWe
手机 C 3 }ee3'LUPX
23、说明:初始化表table1 j`_Z`eG
TRUNCATE TABLE table1 9h<iw\$'
24、说明:选择从10到15的记录 iztgk/(+G
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc !Wy&+H*0
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三、技巧 3Qp6$m
1、1=1,1=2的使用,在SQL语句组合时用的较多 aw7pr464
"where 1=1" 是表示选择全部 "where 1=2"全部不选, {@s6ly].
如: $>Gf;k
if @strWhere !='' tq*{Hil>P`
begin ;cb='s
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere [?da BXS
end :ra[e(l9
else [p)2!]y
begin y }h2
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 7e{w,.ny!
end 2(GLc*B>
我们可以直接写成 =wa5\p/
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere -CPLgT
2、收缩数据库 FH;)5GGnv
--重建索引 fQw|SW
DBCC REINDEX Eb8z`@p
DBCC INDEXDEFRAG GB}X
--收缩数据和日志 y;hco
DBCC SHRINKDB }-vP~I
DBCC SHRINKFILE ^SS9BQ*m
3、压缩数据库 $:?=A5ttuo
dbcc shrinkdatabase(dbname) @d|]BqQ4jh
4、转移数据库给新用户以已存在用户权限 !DKl:8mx4
exec sp_change_users_login 'update_one','newname','oldname' @VsK7Eo
go fi6_yFl
5、检查备份集 z7a@'+'
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' w_Z*X5u
6、修复数据库 sZokiFJ
ALTER DATABASE [dvbbs] SET SINGLE_USER -Q1~lN m:
GO b+BX >$
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK xCMuq9zt@
GO C+gu'hD
ALTER DATABASE [dvbbs] SET MULTI_USER 1i Q(q\%
GO 5zt5]zl'
7、日志清除 l_2YPon
SET NOCOUNT ON +:z%#D
DECLARE @LogicalFileName sysname, |mz0
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@MaxMinutes INT, aQ)g7C
@NewSize INT uJ,I6P~9
USE tablename -- 要操作的数据库名 -AKbXkc~\
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 u_$Spbc]/
@MaxMinutes = 10, -- Limit on time allowed to wrap log. 6<UI%X
@NewSize = 1 -- 你想设定的日志文件的大小(M) ML
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-- Setup / initialize oXqx]@7
DECLARE @OriginalSize int tNW0 C]
SELECT @OriginalSize = size ^X<ytOd5
FROM sysfiles 3N{
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WHERE name = @LogicalFileName E8We2T[^M
SELECT 'Original Size of ' + db_name() + ' LOG is ' + |U="B4
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + td2bL4
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' q -^Z=,<
FROM sysfiles [_p&,$z8[
WHERE name = @LogicalFileName DzY`O@D[
CREATE TABLE DummyTrans s06R~P4
(DummyColumn char (8000) not null) d.NB@[?*
DECLARE @Counter INT, _\FA}d@N
@StartTime DATETIME, y;HJ"5.Mw
@TruncLog VARCHAR(255) 7JP.c@s
SELECT @StartTime = GETDATE(), Zg!E}B:z
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' J_XbtCmt
DBCC SHRINKFILE (@LogicalFileName, @NewSize) f&Meiu+
EXEC (@TruncLog) f/=H#'+8
-- Wrap the log if necessary. *\[GfTL
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired OH~I+=}.
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) m*TJ@gI*t
AND (@OriginalSize * 8 /1024) > @NewSize k12mxR/
BEGIN -- Outer loop. PPNZ(j
SELECT @Counter = 0 65pC#$F<x
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) uvGFo)9q3
BEGIN -- update 82z<Q*YP
INSERT DummyTrans VALUES ('Fill Log') QBT_H"[
DELETE DummyTrans NSAp.m
SELECT @Counter = @Counter + 1 =[^_x+x
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END |Oe$)(`|h
EXEC (@TruncLog) L|w}#|-
END MbC&u:@ "v
SELECT 'Final Size of ' + db_name() + ' LOG is ' + &v_b7h
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + {I"d"'h
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' <' b%
FROM sysfiles HoKN<w
WHERE name = @LogicalFileName +JL"Z4b@R}
DROP TABLE DummyTrans FYeUz$/
SET NOCOUNT OFF `)eqTeW
8、说明:更改某个表 C$EvcF%1
exec sp_changeobjectowner 'tablename','dbo' 1He'\/#
9、存储更改全部表 RIxGwMi%
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch *AN2&>Y
@OldOwner as NVARCHAR(128), jo=,j/,l
@NewOwner as NVARCHAR(128) {2%@I~US
AS Hk;) l3oB
DECLARE @Name as NVARCHAR(128) !8>tT
DECLARE @Owner as NVARCHAR(128) [a1}r=6~
DECLARE @OwnerName as NVARCHAR(128) YPsuG -is
DECLARE curObject CURSOR FOR 81U(*6
select 'Name' = name, q P>Gre
'Owner' = user_name(uid) GvT'v0&+
from sysobjects w.H\j9E
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where user_name(uid)=@OldOwner v#`P?B\
order by name s&zg!~@5b
OPEN curObject 'B4j=K*
FETCH NEXT FROM curObject INTO @Name, @Owner
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WHILE(@@FETCH_STATUS=0)
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BEGIN K3^N_^H
if @Owner=@OldOwner &`[Dl(W
begin d/:zO4v3
set @OwnerName = @OldOwner + '.' + rtrim(@Name) Wtwh.\Jba
exec sp_changeobjectowner @OwnerName, @NewOwner |7l*
end t6O/Q0_
-- select @name,@NewOwner,@OldOwner }x1p~N+;
FETCH NEXT FROM curObject INTO @Name, @Owner "5R8Zl+
END /S+gh;2OC
close curObject l %{$CmG\
deallocate curObject G@igxnm}
GO n~k9Z^ $
10、SQL SERVER中直接循环写入数据 gb_k^wg~1'
declare @i int j:{d'OV
set @i=1 3?GEXO&,E
while @i<30 -kd_gbnr3
begin p<3^= 8Y$
insert into test (userid) values(@i) j5;eSL@/
set @i=@i+1 K"r'w8P
end S_B;m1
小记存储过程中经常用到的本周,本月,本年函数 htGk:
Dateadd(wk,datediff(wk,0,getdate()),-1) f^f{tOX
Dateadd(wk,datediff(wk,0,getdate()),6) cC6W1K!
Dateadd(mm,datediff(mm,0,getdate()),0) G.a^nQ@e%
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) L7tC?F]}SK
Dateadd(yy,datediff(yy,0,getdate()),0) s9Aq-N
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) YS5 Pt)?
上面的SQL代码只是一个时间段 29E9ZjSK
Dateadd(wk,datediff(wk,0,getdate()),-1) NPM}w!
Dateadd(wk,datediff(wk,0,getdate()),6) +LM/< l
就是表示本周时间段. k%Q>lf<e
下面的SQL的条件部分,就是查询时间段在本周范围内的: 7$7Y)&\5w
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) [/ E_v gZ
而在存储过程中 wDV%.Cc
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) Yg6 f
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) g2WDa'{L