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。 %r5&CUE5?
]xfAdBi
s,^?|Eo;0
一、基础 O0xL;@rBe
1、说明:创建数据库 x5m
.MQ J
CREATE DATABASE database-name r^P}xGGK
2、说明:删除数据库 "F+
9xf&r
drop database dbname Jkt
L|u:k
3、说明:备份sql server H^Xw<Z=
--- 创建 备份数据的 device DYH-5yX7
USE master Y*``C):K%
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' $JTy`g0>x
--- 开始 备份 Do(7LidC5
BACKUP DATABASE pubs TO testBack [pbX_
4、说明:创建新表 T\:3(+uK
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) =&,zWNz)
根据已有的表创建新表: =~Jv*c
A:create table tab_new like tab_old (使用旧表创建新表) zQ
{g~x
B:create table tab_new as select col1,col2... from tab_old definition only GI$t8{M
5、说明:删除新表 ',0~ \V
drop table tabname vjJ!d#8
6、说明:增加一个列 Cc]s94
Alter table tabname add column col type ~}4o=O(
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。 QB@qzgEJ!,
7、说明:添加主键: Alter table tabname add primary key(col) f?F
i{m
说明:删除主键: Alter table tabname drop primary key(col) 8'*z>1ZS5
8、说明:创建索引:create [unique] index idxname on tabname(col....) BzA(yCu$:
删除索引:drop index idxname "zw?AC6
注:索引是不可更改的,想更改必须删除重新建。 76)(G/
9、说明:创建视图:create view viewname as select statement j:|60hDz^
删除视图:drop view viewname mf@YmKbp
10、说明:几个简单的基本的sql语句 -3VxjycY
选择:select * from table1 where 范围 | qHWM
插入:insert into table1(field1,field2) values(value1,value2) $BE^'5G&4Y
删除:delete from table1 where 范围 ~u8}s4
更新:update table1 set field1=value1 where 范围 aQN`C{nY
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! #rV=!j||
排序:select * from table1 order by field1,field2 [desc] @DkPJla&
总数:select count as totalcount from table1 ok'0Byo
求和:select sum(field1) as sumvalue from table1 _OcgD<
平均:select avg(field1) as avgvalue from table1 ;ijJ%/
最大:select max(field1) as maxvalue from table1 5"y
p|Yl
最小:select min(field1) as minvalue from table1 svyC(m)'
5S$HDO&
t2OXm
Rv q_Zsm
11、说明:几个高级查询运算词 GU'5`Yzd9
f\~e&`PV
v5wI?HE
A: UNION 运算符 l4F4o6:]n
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。 q) /;|h
B: EXCEPT 运算符 *8/Q_w
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。 2{p`"xX
C: INTERSECT 运算符 p/lMv\`5
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。 GQ|kcY=
注:使用运算词的几个查询结果行必须是一致的。 -5vc0"?E
12、说明:使用外连接 z}C#+VhQ`
A、left outer join: 35RH|ci&
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。 #Opfc8pm'
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 j#&sZ$HQ4
B:right outer join: 4g\a$7r
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 4PD"[a="
C:full outer join: r=L9x/r
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 K^{`8E&A
;
tvB{s_
{, APZ`q|
二、提升 r.i.w0B(
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) a4`@z:l
法一:select * into b from a where 1<>1 8ZG'?A+{
法二:select top 0 * into b from a ^#3$C?d
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) gyCb\y+\a
insert into b(a, b, c) select d,e,f from b; $o]zNW;X
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) ;S`N q%,
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 mkE*.I0=
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. IH~H6US
4、说明:子查询(表名1:a 表名2:b) 2z0HB+Y}x
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) (m04Z2#
5、说明:显示文章、提交人和最后回复时间 mZ/B:)_
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 1LPfn(
6、说明:外连接查询(表名1:a 表名2:b) 'b661,+d
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c yH#;k:O=
7、说明:在线视图查询(表名1:a ) [p o+a@ %
select * from (SELECT a,b,c FROM a) T where t.a > 1; kOdS^-
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 =53LapTPJ
select * from table1 where time between time1 and time2 3<mv9U(
select a,b,c, from table1 where a not between 数值1 and 数值2 \|62E):i1
9、说明:in 的使用方法 87<y_P@{
select * from table1 where a [not] in ('值1','值2','值4','值6') mnmwO(.
10、说明:两张关联表,删除主表中已经在副表中没有的信息 oN `tZ;a
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) #mkr]K8A4
11、说明:四表联查问题: m qw!C
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... lmmyDg1R
12、说明:日程安排提前五分钟提醒 [7I|8
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 ejr"(m(Xe
13、说明:一条sql 语句搞定数据库分页 cWRB=`=qz
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 !+hX$_RT
14、说明:前10条记录 VpVw:Rh>
select top 10 * form table1 where 范围 huKz["]z[
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.) p*npY"}v
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) B. P64"w
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 "BFW&<1
(select a from tableA ) except (select a from tableB) except (select a from tableC) '|XP}V0I
17、说明:随机取出10条数据 e/Q[%y.X
select top 10 * from tablename order by newid() 5\4>H6
18、说明:随机选择记录 o~4n8
select newid() !zJ.rYZ=g`
19、说明:删除重复记录 ~-:CN(U
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) zi-+@9T
20、说明:列出数据库里所有的表名 ~!&[;EM<bm
select name from sysobjects where type='U' yPQ{tS*t
21、说明:列出表里的所有的 $s]@%6f
select name from syscolumns where id=object_id('TableName') iMA) (ZS
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。 %BG5[XQ7
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 xrX("ili
显示结果: O4E2)N
type vender pcs |@ldXuYb
电脑 A 1 w5*18L=O\
电脑 A 1 hYWWvJ)S
光盘 B 2 T=R94
光盘 A 2 X^.r@tT
手机 B 3 s lI)"+6
手机 C 3 c''O+,L1+
23、说明:初始化表table1 rSJ}qRXwU
TRUNCATE TABLE table1 =VY4y]V
24、说明:选择从10到15的记录 {VNeh
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Aj`4uFhiL
C|lMXp\*
unX^ MPpw
}jk^M|Z"Oz
三、技巧 >{??/fBd-
1、1=1,1=2的使用,在SQL语句组合时用的较多 {(q Un
"where 1=1" 是表示选择全部 "where 1=2"全部不选, Bhs`Y/Ls-
如: )?xt=9Lh
if @strWhere !='' F"F(s!
begin /Z@.;M
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere CTP%
end cq=R
else }>1E,3A:%G
begin eS.]@E-T
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' A"k,T7B
end j?mJ1J5
我们可以直接写成 _0f[.vN
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere <n:?WP~U
2、收缩数据库 \c\=S
--重建索引 ueg X
DBCC REINDEX Grub1=6l
DBCC INDEXDEFRAG +]e4c;`ko}
--收缩数据和日志 5 O6MI4:
DBCC SHRINKDB FD-)nv2:
DBCC SHRINKFILE 5;Z~+$1
3、压缩数据库 ""a8eB6
dbcc shrinkdatabase(dbname) co@8w!W
4、转移数据库给新用户以已存在用户权限 lz*2wGI9
exec sp_change_users_login 'update_one','newname','oldname' @t^2/H
?O
go <|_Ey)1
6
5、检查备份集 JQ1VCG
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ?yU#'`q
6、修复数据库 zc{C+:3$^
ALTER DATABASE [dvbbs] SET SINGLE_USER "D/ fB%h`
GO 8`~]9ej
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK Tc*PDt0C
GO <f*0 XJ#
ALTER DATABASE [dvbbs] SET MULTI_USER ;i:7E#@
GO '
#mC4\<W8
7、日志清除 FV9RrI2
SET NOCOUNT ON HkN +:
DECLARE @LogicalFileName sysname, cs5Xd
@MaxMinutes INT, p~b$+8#+
@NewSize INT w '"7~uN
USE tablename -- 要操作的数据库名 3OZ}&[3
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 :W&\})
@MaxMinutes = 10, -- Limit on time allowed to wrap log. {h=Ai[|l4Q
@NewSize = 1 -- 你想设定的日志文件的大小(M) ?7+2i\L
-- Setup / initialize CP'-CQ\Q
DECLARE @OriginalSize int wf4Q}l2,d
SELECT @OriginalSize = size k8JPu"R
FROM sysfiles 9x1Dyz 2?F
WHERE name = @LogicalFileName Z4!3I@yZ
SELECT 'Original Size of ' + db_name() + ' LOG is ' + |eqDT,4
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + r=`>'3
} x
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 8B+uNN~%]
FROM sysfiles !v`=EF.
WHERE name = @LogicalFileName cjW]Nw
CREATE TABLE DummyTrans [Wh 43Z
(DummyColumn char (8000) not null) 8HOmWQS
DECLARE @Counter INT, a~|ge9?
(
@StartTime DATETIME, E$wB bm
@TruncLog VARCHAR(255) h CiblM
SELECT @StartTime = GETDATE(), \2`U$3Q
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' u&Fm}/x
DBCC SHRINKFILE (@LogicalFileName, @NewSize) lrzW H0Q
EXEC (@TruncLog) 3{l"E(qqZ
-- Wrap the log if necessary. 0{yx*}.
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ^PI49iB
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 9s)oC$\
AND (@OriginalSize * 8 /1024) > @NewSize `jHGNi
BEGIN -- Outer loop. fjFy$NX&>
SELECT @Counter = 0 =jN]ckn
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) 'zb7:[[7%
BEGIN -- update Xy{+=UY
INSERT DummyTrans VALUES ('Fill Log') 8f.La
DELETE DummyTrans ?1uAY.~ZZB
SELECT @Counter = @Counter + 1 8{YxUD
END V("1\
EXEC (@TruncLog) _biJch
END D/WS
SELECT 'Final Size of ' + db_name() + ' LOG is ' + {JgN^R<5<f
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + OOCeZ3yF(
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' kWd'gftQ
FROM sysfiles t/Fe"T[,V
WHERE name = @LogicalFileName UU;:x"4
DROP TABLE DummyTrans z#4g,)ZX
SET NOCOUNT OFF 7'S]
8、说明:更改某个表 =-qsz^^a-
exec sp_changeobjectowner 'tablename','dbo' x_K%
9、存储更改全部表 *`#,^p`j
b
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch TRZ^$<AG
@OldOwner as NVARCHAR(128), vF&b|V+,
@NewOwner as NVARCHAR(128) Nz;;X\GI
AS c0 |p34
DECLARE @Name as NVARCHAR(128) U6Ak"
DECLARE @Owner as NVARCHAR(128) ThxrhQ
q[+
DECLARE @OwnerName as NVARCHAR(128) &; \v_5N6
DECLARE curObject CURSOR FOR v,&2!Zv
select 'Name' = name, sFQ|lU" n
'Owner' = user_name(uid) 3_$eQ`AAA
from sysobjects Q6K)EwN
where user_name(uid)=@OldOwner U\ued=H
order by name F
4/Uu"J:
OPEN curObject R=PzR;8
FETCH NEXT FROM curObject INTO @Name, @Owner d3GK.8y_z
WHILE(@@FETCH_STATUS=0) meR2"JN'
BEGIN MlFvDy
if @Owner=@OldOwner jGn^<T\
begin n lW&(cH
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 0, /x#
exec sp_changeobjectowner @OwnerName, @NewOwner &iZYBa
end kdCOcJB
-- select @name,@NewOwner,@OldOwner Be+:-t)
FETCH NEXT FROM curObject INTO @Name, @Owner \0h/~3
END kP$gl|
close curObject 37xxVbik
deallocate curObject kg@h R}
GO [JoTWouNU
10、SQL SERVER中直接循环写入数据 {%{GZ
declare @i int cAS_?"V
a
set @i=1 0K ?(xB
while @i<30 YHYB.H)
begin {O)&5
insert into test (userid) values(@i) W#j,{&KVn
set @i=@i+1 @3YuV=QfH
end 4Z}{hc\J
小记存储过程中经常用到的本周,本月,本年函数 F/sBr7I
Dateadd(wk,datediff(wk,0,getdate()),-1) mx~sxYa
Dateadd(wk,datediff(wk,0,getdate()),6) d&`j8O
Dateadd(mm,datediff(mm,0,getdate()),0) jm\#($gl=
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0))
#Uh 5tc
Dateadd(yy,datediff(yy,0,getdate()),0) pm\X*t}L
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) |@.<}/
上面的SQL代码只是一个时间段 BA,6f?ktXS
Dateadd(wk,datediff(wk,0,getdate()),-1) s.' \&B[
Dateadd(wk,datediff(wk,0,getdate()),6) RWFf-VA?
就是表示本周时间段. G:`Jrh
下面的SQL的条件部分,就是查询时间段在本周范围内的: D}sGBsOW
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) zF&UdS3
而在存储过程中 5#.\pR{Gd
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) G4' U;
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) cg00t+