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。 WLr\ l29
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一、基础 #R&Dgt
1、说明:创建数据库 Hm=!;xAFX
CREATE DATABASE database-name VEAf,{)Q
2、说明:删除数据库 eNN)2-96
drop database dbname s;-(dQ{O
3、说明:备份sql server `TNWLD@Z
--- 创建 备份数据的 device Y{P0?`
USE master 8=;'kEU
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' %{$iN|%J%$
--- 开始 备份 P$E #C:=
BACKUP DATABASE pubs TO testBack `Q d_Gu,M
4、说明:创建新表 ha6jbni
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) T/NeoU3 p
根据已有的表创建新表: 0)/L+P5
A:create table tab_new like tab_old (使用旧表创建新表) CR$\$-
B:create table tab_new as select col1,col2... from tab_old definition only sdq8wn
5、说明:删除新表 X) lz BM
drop table tabname ,v;P@RL|g
6、说明:增加一个列 6 /8?:
Alter table tabname add column col type E?>
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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。 W79wz\a
7、说明:添加主键: Alter table tabname add primary key(col) }:UNL^e?
说明:删除主键: Alter table tabname drop primary key(col) ]qZs^kQ
8、说明:创建索引:create [unique] index idxname on tabname(col....) Y#3<w
删除索引:drop index idxname E0XfM B]+
注:索引是不可更改的,想更改必须删除重新建。 b(8#*S!U
9、说明:创建视图:create view viewname as select statement 7MXi_V;p<
删除视图:drop view viewname eR,ePyA;
10、说明:几个简单的基本的sql语句 5[Sa7Mk
选择:select * from table1 where 范围 }?zy*yL
插入:insert into table1(field1,field2) values(value1,value2) AS[yNCsjC
删除:delete from table1 where 范围 {ETuaFDM
更新:update table1 set field1=value1 where 范围 feOX]g#
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! qx3@]9
排序:select * from table1 order by field1,field2 [desc] $[5S M>e]
总数:select count as totalcount from table1 &)?ECj0`
求和:select sum(field1) as sumvalue from table1 2y/|/IW=
平均:select avg(field1) as avgvalue from table1 eh=.Q<N
最大:select max(field1) as maxvalue from table1 HyKvDJ
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最小:select min(field1) as minvalue from table1 92|\`\LP%
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11、说明:几个高级查询运算词 fi*@m,-
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A: UNION 运算符 zS]8ma
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。 "8{#R*p
B: EXCEPT 运算符 9sQ7wlK
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。 {DzOXTI[Y
C: INTERSECT 运算符 BeAkG_uG
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。 y7ng/vqM7
注:使用运算词的几个查询结果行必须是一致的。 ZzZy2.7
12、说明:使用外连接 `9IG//
A、left outer join: N?]HWP^pg
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。 4[=vt
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 ~gz_4gzb
B:right outer join: @VlDi1
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。 (~6oA f
C:full outer join: !g=2U`j^
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。 "uR,WY
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二、提升 49vKb(bz{
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) AN-qcp6=o
法一:select * into b from a where 1<>1 Z_iVOctP
法二:select top 0 * into b from a '6Lw<#It
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ] B
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insert into b(a, b, c) select d,e,f from b; \.m"u14[b
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) 6_KO6O7g
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 {9>LF
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. p%;n4*b2
4、说明:子查询(表名1:a 表名2:b) 9"T&P_
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) kzq3-NTV
5、说明:显示文章、提交人和最后回复时间 mUFg(;ya
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b J9+<9g4-t
6、说明:外连接查询(表名1:a 表名2:b) :m~R<BQ"
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c [wHGt?R
7、说明:在线视图查询(表名1:a ) -\ {.]KL
select * from (SELECT a,b,c FROM a) T where t.a > 1; =Kf]ZKj)
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 ^! ?wh
select * from table1 where time between time1 and time2 ma__LWKM,
select a,b,c, from table1 where a not between 数值1 and 数值2 QtM9G@%
9、说明:in 的使用方法 ;- ~}g 7$
select * from table1 where a [not] in ('值1','值2','值4','值6') Fp3NWvu
10、说明:两张关联表,删除主表中已经在副表中没有的信息 (-'Jf#&X^
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) <kJ,E[4`
11、说明:四表联查问题: PNNY_t +I
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 ..... :xd)]Ns
12、说明:日程安排提前五分钟提醒 6|h~pH
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 46p%y
13、说明:一条sql 语句搞定数据库分页 &-l(nr]h]
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 A.`)
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14、说明:前10条记录 -u!{8S~wA
select top 10 * form table1 where 范围 EZICH&_
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.) kkA5pbS
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) y2nwDw(xF
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 Pe-1o#7~W
(select a from tableA ) except (select a from tableB) except (select a from tableC) >M~wFs$~
17、说明:随机取出10条数据 :=CRsQAn
select top 10 * from tablename order by newid() J.%%]-f=&
18、说明:随机选择记录 zTP|H5HyK
select newid() h^Bp^V5#
19、说明:删除重复记录 YzasT:EZN
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) zh{:zT)(1
20、说明:列出数据库里所有的表名 h!>K[*
select name from sysobjects where type='U' %3ieR}:/e&
21、说明:列出表里的所有的 s48 { R4
select name from syscolumns where id=object_id('TableName') tQTVP 2:Y
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。 ix.I)
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 YfB8
显示结果: 'WF Ey>1#
type vender pcs &\w:jI44Bs
电脑 A 1 -pb>=@Yq
电脑 A 1 w-2?|XvDmf
光盘 B 2 k;)t}7(
光盘 A 2 d
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手机 B 3 V~tZNRJ-
手机 C 3 7Pb:z4j
23、说明:初始化表table1 g`NJ
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TRUNCATE TABLE table1 Vdpvo;4uy
24、说明:选择从10到15的记录 _s(izc
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc BAy]&q|.
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三、技巧 &O&;v|!9
1、1=1,1=2的使用,在SQL语句组合时用的较多 f&ZFG>)6
"where 1=1" 是表示选择全部 "where 1=2"全部不选, :4HZ>!i
如: KV1/!r+*
if @strWhere !='' b@p3iq:
begin VH>?%aL
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere [H-r0Ah
end |_ChK6Q?v
else +?&|p0
begin pz
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set @strSQL = 'select count(*) as Total from [' + @tblName + ']' @+iO0?f
end v +$3Z5
我们可以直接写成 &I= 27!S
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 1kDr;.m%
2、收缩数据库 }\-"L/D?+
--重建索引 w%Bo7 'o)V
DBCC REINDEX 8dBG ZwyET
DBCC INDEXDEFRAG +f+#W
--收缩数据和日志 <"}Gvi
DBCC SHRINKDB Iz^lED
DBCC SHRINKFILE &a/F"?9jL
3、压缩数据库 9hNHcl.
dbcc shrinkdatabase(dbname) D
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4、转移数据库给新用户以已存在用户权限 >sfH[b
exec sp_change_users_login 'update_one','newname','oldname' ue/GB+U
go 0QakFt
5、检查备份集 0P%,1M3d
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' |o5F%1o
6、修复数据库 ~"IjT'W3
ALTER DATABASE [dvbbs] SET SINGLE_USER 3lW7auH4Y{
GO u djahI<{
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK })Pq!u:3
GO -\2T(3P
ALTER DATABASE [dvbbs] SET MULTI_USER reU*apZ/
GO qRX:eo
7、日志清除 GELxS!
SET NOCOUNT ON r6x"D3
DECLARE @LogicalFileName sysname, Z'@a@Y+
@MaxMinutes INT, 'IykIf
@NewSize INT q|EE
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USE tablename -- 要操作的数据库名 /&T"w,D
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ophQdJM
@MaxMinutes = 10, -- Limit on time allowed to wrap log. gPA),
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@NewSize = 1 -- 你想设定的日志文件的大小(M) Gv$}>YJ
-- Setup / initialize :SUU)jLq
DECLARE @OriginalSize int /4 Q^L>a
SELECT @OriginalSize = size ~A X@o-WU
FROM sysfiles 6q8b>LG|
WHERE name = @LogicalFileName u#>*"4Q
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 5Vj t!%?r
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + jcY:a0 [{D
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' YtWO=+rX
FROM sysfiles \i}:Vb(^
WHERE name = @LogicalFileName Wu\szI"
CREATE TABLE DummyTrans |J_kS90=
(DummyColumn char (8000) not null) m:sT)
DECLARE @Counter INT, p2\mPFxEP
@StartTime DATETIME, FK:Tni
@TruncLog VARCHAR(255) \{Yi7V
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SELECT @StartTime = GETDATE(), j)vfI>
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 1~|o@CO
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 5|pPzEA>
EXEC (@TruncLog) %YhM?jMW
-- Wrap the log if necessary. 0IP5&[-P
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired *fIb|r
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) *It`<F|
AND (@OriginalSize * 8 /1024) > @NewSize R{X@@t9@
BEGIN -- Outer loop. tsqkV7?
SELECT @Counter = 0 XXe?@w2{
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) 2y"|l
BEGIN -- update :v(fgS2\
INSERT DummyTrans VALUES ('Fill Log') =Ll:Ba Q
DELETE DummyTrans ]a
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SELECT @Counter = @Counter + 1 ;t_'87h$y
END vnrP;T=^
EXEC (@TruncLog) );~JyoDo
END gTby%6-\|
SELECT 'Final Size of ' + db_name() + ' LOG is ' + :I)WSXP9h
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + jH4'jB
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' B7R*g,(
FROM sysfiles =MP?aH
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WHERE name = @LogicalFileName ;%/Kh :Vg
DROP TABLE DummyTrans %~$P.Zh
SET NOCOUNT OFF w:0=L`<Eu
8、说明:更改某个表 >w}5\4j
exec sp_changeobjectowner 'tablename','dbo' E/Ng
9、存储更改全部表 $!Pm*s
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Z}E.s@w
@OldOwner as NVARCHAR(128), i`F8kg`_K
@NewOwner as NVARCHAR(128) ._$tNGI4
AS W
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DECLARE @Name as NVARCHAR(128) ='p&T|&
DECLARE @Owner as NVARCHAR(128) 5VXI/Lw#
DECLARE @OwnerName as NVARCHAR(128) 2VY.#9vl
DECLARE curObject CURSOR FOR m&36$>r=
select 'Name' = name, B,f4<
'Owner' = user_name(uid) ~Ip-@c}'j
from sysobjects js~?y|e8k
where user_name(uid)=@OldOwner 7H~J?_
order by name ap7ZT7KW
OPEN curObject O`pqS\H
FETCH NEXT FROM curObject INTO @Name, @Owner 2^*a$OJ
WHILE(@@FETCH_STATUS=0) &.ENcEic
BEGIN aSy^(WN8
if @Owner=@OldOwner wk'12r6=(-
begin M
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set @OwnerName = @OldOwner + '.' + rtrim(@Name) Q`Z=}^
exec sp_changeobjectowner @OwnerName, @NewOwner +wwb+aG6{
end 2yt)"DnFk
-- select @name,@NewOwner,@OldOwner 0j--X?-
FETCH NEXT FROM curObject INTO @Name, @Owner ^@"EI|fsP
END G';yb^DB
close curObject X5V8w4NN
deallocate curObject X:ck
GO eMDO;q
10、SQL SERVER中直接循环写入数据 5ml#/kE
declare @i int (H/2{##
set @i=1 J2ryYdo>
while @i<30 U<