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。 P*g:rg
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一、基础 +L-(Lz[p
1、说明:创建数据库 !)HB+yr
CREATE DATABASE database-name a~wlD.P
2、说明:删除数据库 0NMmN_Lr
drop database dbname ]EfM;'j[
3、说明:备份sql server LB/1To
--- 创建 备份数据的 device 8],tGMu
USE master It8s#o q8
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' -`ss7j&b3
--- 开始 备份 Co^GsUJ
BACKUP DATABASE pubs TO testBack 0I7 r{T
4、说明:创建新表 cL^r^kL("
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) I`uOsZBO/
根据已有的表创建新表: _5H0<%\
A:create table tab_new like tab_old (使用旧表创建新表) UE 1tm
B:create table tab_new as select col1,col2... from tab_old definition only 3)3$ L
5、说明:删除新表 J{r3y&:
drop table tabname v
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6、说明:增加一个列 CH] +S>$
Alter table tabname add column col type gT#hF]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。 _Eus7
7、说明:添加主键: Alter table tabname add primary key(col) .*{0[
说明:删除主键: Alter table tabname drop primary key(col) OY,iz
8、说明:创建索引:create [unique] index idxname on tabname(col....) |*JMCI@Mz
删除索引:drop index idxname wj-z;YCV
注:索引是不可更改的,想更改必须删除重新建。 d6zfP1lQ
9、说明:创建视图:create view viewname as select statement @%
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删除视图:drop view viewname VskdC?yIp
10、说明:几个简单的基本的sql语句 ~!#2s'
选择:select * from table1 where 范围 Lem:zXj
插入:insert into table1(field1,field2) values(value1,value2) ?vg|;Q
删除:delete from table1 where 范围 gh<2i\})'
更新:update table1 set field1=value1 where 范围 d#u*NwY}
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ]^v*2!_(
排序:select * from table1 order by field1,field2 [desc] t$(<9
总数:select count as totalcount from table1 QRz5eGpW
求和:select sum(field1) as sumvalue from table1 w3K>IDWI7
平均:select avg(field1) as avgvalue from table1 +OfHa\Nz
最大:select max(field1) as maxvalue from table1 !w{(}n2Wq
最小:select min(field1) as minvalue from table1 YjzGF=g#
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11、说明:几个高级查询运算词 ^$~&e :{
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A: UNION 运算符 yBnUz"
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。 ^wMZG'/
B: EXCEPT 运算符 x2Dg92
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。 0jMS!"k
C: INTERSECT 运算符 zTW)SX_O
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。 Qkx}A7sK
注:使用运算词的几个查询结果行必须是一致的。 f_;6uCCO
12、说明:使用外连接 &m{vLw
A、left outer join: _)-y&
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。 3?uah'D5
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 W7?f_E\>W
B:right outer join: I2e@_[
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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。 Km!~zG7<
C:full outer join: NzG] nsw
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。 *s6(1S
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二、提升 Ag_I'
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) (T1d!v"~"
法一:select * into b from a where 1<>1 z99jW<*0
法二:select top 0 * into b from a I@l }%L
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) N5Ih+8zT
insert into b(a, b, c) select d,e,f from b; M1 _1(LSU
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) P>qDQ1
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 6+W`:0je
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. c|(&6(r
4、说明:子查询(表名1:a 表名2:b) {7d\du&G
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) V[avV*;3i
5、说明:显示文章、提交人和最后回复时间 +uB.)wr
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b }<mK79m
6、说明:外连接查询(表名1:a 表名2:b) mecm,xwm
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c C0[Z>$
7、说明:在线视图查询(表名1:a ) +dJLT}I8M
select * from (SELECT a,b,c FROM a) T where t.a > 1; *L=F2wW
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 BiD}C
select * from table1 where time between time1 and time2 H\<^p",`
select a,b,c, from table1 where a not between 数值1 and 数值2 =O'>H](Q
9、说明:in 的使用方法 6w*q~{"(
select * from table1 where a [not] in ('值1','值2','值4','值6') n--w-1
10、说明:两张关联表,删除主表中已经在副表中没有的信息 zz1]6B*eX
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 1D2Yued
11、说明:四表联查问题: ,&0iFUwN_
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 ..... Or"+d 5
12、说明:日程安排提前五分钟提醒 7cly{U"
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 <BhNmEo)2
13、说明:一条sql 语句搞定数据库分页 E2yL9]K2
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 SEsLJ?Dv0
14、说明:前10条记录 _>(qQ-Px
select top 10 * form table1 where 范围 |5#iPw_wMY
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.) C25 2E
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) Ct0YwIR*
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 qL/XGIxL?
(select a from tableA ) except (select a from tableB) except (select a from tableC) :WAFBK/x
17、说明:随机取出10条数据 O%p+P<J
select top 10 * from tablename order by newid() d>}R3T
18、说明:随机选择记录 Q}kXxud
select newid() g<jgR*TE`
19、说明:删除重复记录 O`D,> =[
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) Uq:CM6q\
20、说明:列出数据库里所有的表名 b";D*\=x
select name from sysobjects where type='U' !y-,r4\@`
21、说明:列出表里的所有的 ~v^I*/uY
select name from syscolumns where id=object_id('TableName') BM_Rlcx~
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。 QRAw#
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 >SaT?k1E
显示结果: %G/j+Pf
type vender pcs ,,CheRO
电脑 A 1
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电脑 A 1 2pV@CT
光盘 B 2 ]2@g 5H}M
光盘 A 2 *$v`5rP
手机 B 3 tP0!TkTo9
手机 C 3 lt{yo\
23、说明:初始化表table1 e2vLUlL8
TRUNCATE TABLE table1 M\)(_I)V=
24、说明:选择从10到15的记录 =`fz#Mfd
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc wH0Ks5
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三、技巧 m1,yf*U
1、1=1,1=2的使用,在SQL语句组合时用的较多 T;Zv^:]0
"where 1=1" 是表示选择全部 "where 1=2"全部不选, ]n (:X
如: $}z%}v
if @strWhere !='' RAi]9` *7
begin Xi"<'E3_
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere #xe-Yw1!
end V;%DS)-
else : ?J0e4.]
begin ,e!9WKJ
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set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 3W.5[;}
end k!=
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我们可以直接写成 pjrzoMF
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere jgd^{!
2、收缩数据库 2kV{|`1
--重建索引 bbAJ5EqL
DBCC REINDEX j
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DBCC INDEXDEFRAG ns`njx}C
--收缩数据和日志 <OA[u-ph%S
DBCC SHRINKDB e'L$g-;>4b
DBCC SHRINKFILE sB'Z9
3、压缩数据库 &#DKB#.2
dbcc shrinkdatabase(dbname) PR;A 0
4、转移数据库给新用户以已存在用户权限 )]P%=
exec sp_change_users_login 'update_one','newname','oldname'
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go
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5、检查备份集 <6[P5>
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' PDtLJt$
6、修复数据库 {j4J(dtO
ALTER DATABASE [dvbbs] SET SINGLE_USER e!.r- v9
GO fd /?x^Z
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK J~(M%]
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GO -wUw)gJbM
ALTER DATABASE [dvbbs] SET MULTI_USER J4>k9~q
GO ]] Jg%}o
7、日志清除 &HIG776
SET NOCOUNT ON U1~6 o"1H
DECLARE @LogicalFileName sysname, +u]L#].;
@MaxMinutes INT, gaa;PX
@NewSize INT #(f- cK
USE tablename -- 要操作的数据库名 V/CZcMY_
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 SRBQ"X[M2
@MaxMinutes = 10, -- Limit on time allowed to wrap log. `8<h aU
@NewSize = 1 -- 你想设定的日志文件的大小(M) usz H1@g'
-- Setup / initialize siK:?A@4D
DECLARE @OriginalSize int fkWTO"f-
SELECT @OriginalSize = size JtGBNz!"
FROM sysfiles z4iZE*ZS
WHERE name = @LogicalFileName ~
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SELECT 'Original Size of ' + db_name() + ' LOG is ' + FNB4YZ6
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + VT~jgsY
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ``9`Xq
FROM sysfiles =BNS3W6
WHERE name = @LogicalFileName A@qwD300Vo
CREATE TABLE DummyTrans <Z58"dg.5
(DummyColumn char (8000) not null) +tSfx
DECLARE @Counter INT, dPO|x+N,
@StartTime DATETIME, `ot<BwxJ
@TruncLog VARCHAR(255) Md(h-wYr
SELECT @StartTime = GETDATE(), (cLcY%$
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' kjOPsz*0
DBCC SHRINKFILE (@LogicalFileName, @NewSize) fjwUh>[ }
EXEC (@TruncLog) h:l4:{A64
-- Wrap the log if necessary. A57e]2_
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired DC6xet{
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ._5"FUg
AND (@OriginalSize * 8 /1024) > @NewSize ^,WXvOy
BEGIN -- Outer loop. &R~)/y0]
SELECT @Counter = 0 \CDzVO0^
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) :HTV 8;yc
BEGIN -- update ^DWhIxBh
INSERT DummyTrans VALUES ('Fill Log') :jUu_s}
DELETE DummyTrans _q/UDf1
SELECT @Counter = @Counter + 1 +PGtO9}B
END 3I%F,-r
EXEC (@TruncLog) ,s.{R
END Weu%&u-
SELECT 'Final Size of ' + db_name() + ' LOG is ' + %}x$YDO
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + =V(|3?N
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' AKkr
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FROM sysfiles |ZBHXv
WHERE name = @LogicalFileName PShluhY
DROP TABLE DummyTrans _8eN^oc%
SET NOCOUNT OFF s!Y`1h{
8、说明:更改某个表 )/_T`cN
exec sp_changeobjectowner 'tablename','dbo' whdoG{/
9、存储更改全部表 U9:w ^t[Pp
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch vh"> Z4
@OldOwner as NVARCHAR(128), Z?_t3
@NewOwner as NVARCHAR(128) Lkl+f~m
AS q]r?s%x
DECLARE @Name as NVARCHAR(128) byB
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DECLARE @Owner as NVARCHAR(128) TU(w>v
DECLARE @OwnerName as NVARCHAR(128) g9K7_T #W
DECLARE curObject CURSOR FOR i<uWLhgh1$
select 'Name' = name, SB}0u=5
'Owner' = user_name(uid) rbD}fUg
from sysobjects +M %zOX/
where user_name(uid)=@OldOwner 1`z^Xk8vt
order by name |r%lJmBB
OPEN curObject xHo
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FETCH NEXT FROM curObject INTO @Name, @Owner s`E^1jC
WHILE(@@FETCH_STATUS=0) %A ^qm
BEGIN e+ckn
if @Owner=@OldOwner Ja(>!8H>@
begin XBF]|}%
set @OwnerName = @OldOwner + '.' + rtrim(@Name) z0Bw+&^]}
exec sp_changeobjectowner @OwnerName, @NewOwner `PVr;&
end {u4=*>?G
-- select @name,@NewOwner,@OldOwner eTrIN,4
FETCH NEXT FROM curObject INTO @Name, @Owner G<f"_NT
END yQ{xRtNO
close curObject c4AkH|
deallocate curObject qJ8@A}}8
GO Q $5U5hb
10、SQL SERVER中直接循环写入数据
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declare @i int +o7Np|Ou
set @i=1 7UzbS,$x
while @i<30 @cz\'v6E
begin a$K.Or}
insert into test (userid) values(@i) ck"lX[d1
set @i=@i+1 WUnmUW[/
end f#3U,n8:
小记存储过程中经常用到的本周,本月,本年函数 asQXl#4r
Dateadd(wk,datediff(wk,0,getdate()),-1) @ a?^2X^
Dateadd(wk,datediff(wk,0,getdate()),6) K9 tuiD+j
Dateadd(mm,datediff(mm,0,getdate()),0) EX.`6,:+2
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) (ev(~Wc
Dateadd(yy,datediff(yy,0,getdate()),0) Z F&aV?
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) a&*fk ?o
上面的SQL代码只是一个时间段 gPrIu+|F
Dateadd(wk,datediff(wk,0,getdate()),-1) f3u^:6U~
Dateadd(wk,datediff(wk,0,getdate()),6) |&hu3-(
就是表示本周时间段. *'q6#\#.
下面的SQL的条件部分,就是查询时间段在本周范围内的: },@1i<Bb
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 5C^oqUZ
而在存储过程中 d
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select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) ^A"TY
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ci~pM<+