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。 2b{@]Fp
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一、基础 t!+%g) @
1、说明:创建数据库 7$E2/@f
CREATE DATABASE database-name @y&h4^)z
2、说明:删除数据库 q[T_*X3o
drop database dbname EbHUGCMO
3、说明:备份sql server $D0)j(v
--- 创建 备份数据的 device 0B#rqTEKu
USE master mP`,I"u
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' #t5JUi%in*
--- 开始 备份 <"j"h=tm}
BACKUP DATABASE pubs TO testBack _dH[STT
4、说明:创建新表 |\yDgs%EGy
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 7z0;FW3>9
根据已有的表创建新表: \`p |,j
A:create table tab_new like tab_old (使用旧表创建新表) X"]mR7k
B:create table tab_new as select col1,col2... from tab_old definition only ?w|\7T.?
5、说明:删除新表 URj%
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drop table tabname hfP(N_""S
6、说明:增加一个列 _&8KB1~
Alter table tabname add column col type )^QG-IM
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 F~11 _
7、说明:添加主键: Alter table tabname add primary key(col) Au\=ypK
说明:删除主键: Alter table tabname drop primary key(col) {d{WMq$
8、说明:创建索引:create [unique] index idxname on tabname(col....) kC,DW%Ls
删除索引:drop index idxname j$JV(fz
注:索引是不可更改的,想更改必须删除重新建。 Ezo" f
9、说明:创建视图:create view viewname as select statement |\{J`5gr
删除视图:drop view viewname {/,+_E/
10、说明:几个简单的基本的sql语句 u8$~N$L
选择:select * from table1 where 范围 g]TI8&tP!L
插入:insert into table1(field1,field2) values(value1,value2) 123-i,epg
删除:delete from table1 where 范围 PdE)m/
更新:update table1 set field1=value1 where 范围 dzk?Zg
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! >u%[J!Y;;
排序:select * from table1 order by field1,field2 [desc] E!oJ0*@
总数:select count as totalcount from table1 d<^6hF
求和:select sum(field1) as sumvalue from table1 _3-,3ia
平均:select avg(field1) as avgvalue from table1 ~"hAb2
最大:select max(field1) as maxvalue from table1 OHXeqjhy
最小:select min(field1) as minvalue from table1 `04Y ;@w
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11、说明:几个高级查询运算词
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A: UNION 运算符 kdZ-<O7@
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 Y7IlqC`i
B: EXCEPT 运算符 2oNPR+
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EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 &~f*q?xR
C: INTERSECT 运算符 *?
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INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 kK_>*iCMo
注:使用运算词的几个查询结果行必须是一致的。 Mz#S5 s
12、说明:使用外连接 o::ymAj
A、left outer join: Yc( )'6
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 A?<"^<A^
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c gJ}'O4*b
B:right outer join: ;L/T}!Dx
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 m'vOFP)'
C:full outer join: I$sm5oL
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。 EXScqGa]
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二、提升 hJL0M!
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) EJiF_
法一:select * into b from a where 1<>1 ;z=C^'
法二:select top 0 * into b from a e?'k[ES^
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) %PNm7s4x2
insert into b(a, b, c) select d,e,f from b; > & lg
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) F$pd]F!#
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 & m ";D
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. -O,O<tOm
4、说明:子查询(表名1:a 表名2:b) P#'DG W&W0
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) 1=cfk#
5、说明:显示文章、提交人和最后回复时间 ^a0-5
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b gB'Ah -@,P
6、说明:外连接查询(表名1:a 表名2:b) OA5md9P;d
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c T;vPR,]rz
7、说明:在线视图查询(表名1:a ) QSQ\@h;E
select * from (SELECT a,b,c FROM a) T where t.a > 1; k>@^M]%
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 MyS7AL
select * from table1 where time between time1 and time2 lKD<
select a,b,c, from table1 where a not between 数值1 and 数值2 b|C,b"$N0
9、说明:in 的使用方法 H0Gp mKYW
select * from table1 where a [not] in ('值1','值2','值4','值6') "7u"d4h-:(
10、说明:两张关联表,删除主表中已经在副表中没有的信息 H@bmLq
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 7'l{I'Z
11、说明:四表联查问题: n"VE!`B
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 ..... ;@UX7NA
12、说明:日程安排提前五分钟提醒 _-2n3py
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 zAdVJ58H
13、说明:一条sql 语句搞定数据库分页 ?
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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 _O71r}4
14、说明:前10条记录 2ZFKjj
select top 10 * form table1 where 范围 o\Vt $
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[+me o
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) LFry?HO,D
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 "I1M$^8n
(select a from tableA ) except (select a from tableB) except (select a from tableC) d}G."wnG9,
17、说明:随机取出10条数据 6je%LHhL
select top 10 * from tablename order by newid() s)ajy^6'M
18、说明:随机选择记录 1$!K2=%OXj
select newid() @9Pn(fd]
19、说明:删除重复记录 L,ey3i7a\
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)
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20、说明:列出数据库里所有的表名 Wn</",Gf
select name from sysobjects where type='U' 1OGv+b)
21、说明:列出表里的所有的 g KY
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select name from syscolumns where id=object_id('TableName') U@ QU8
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。 4BL,/(W]
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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 wOl-iN=
显示结果: SYhspB
type vender pcs +as\>"Cj+2
电脑 A 1 fv7g93
电脑 A 1 m l
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光盘 B 2 Hu!>RSg,,2
光盘 A 2 K%#C+`Ij
手机 B 3 =-&iF
手机 C 3 &:{yf=
23、说明:初始化表table1 *y@]zNPD
TRUNCATE TABLE table1 v=^)`C6Ma
24、说明:选择从10到15的记录 V0&QEul
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc X-^Oz@.>
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三、技巧 #j5^/*XW
1、1=1,1=2的使用,在SQL语句组合时用的较多 KFrmH
"where 1=1" 是表示选择全部 "where 1=2"全部不选, AxQ/
如: yodrX&"
if @strWhere !='' OnJSu
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begin 5~6y.S
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere 9Qd'=JQl
end O&RHCR-\
else >R0j<:p :
begin &3/H
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set @strSQL = 'select count(*) as Total from [' + @tblName + ']' YLd%"H $n
end `I<|*vW
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我们可以直接写成 #FM 'S|
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere O!yn
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2、收缩数据库 ^^(ZK 6 d
--重建索引 Wm/k(R`O<
DBCC REINDEX akoKx)(<
DBCC INDEXDEFRAG Zdz GJ[$
--收缩数据和日志 4vJIO{m
DBCC SHRINKDB aM1JG$+7 G
DBCC SHRINKFILE cHd39H9
3、压缩数据库 d$
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dbcc shrinkdatabase(dbname) )y Y;%
4、转移数据库给新用户以已存在用户权限 bhT]zsBK
exec sp_change_users_login 'update_one','newname','oldname' 2UJ0%k
go : \`MrI^
5、检查备份集 =l_"M
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' Q)dns)_x
6、修复数据库 'hWRwP|
ALTER DATABASE [dvbbs] SET SINGLE_USER D1/$pA+B
GO 9e6{(
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK mw%_yDZ{
GO $dUN+9
ALTER DATABASE [dvbbs] SET MULTI_USER /!3:K<6@
GO 6g&nnA
7、日志清除 Y'R1\Go-
SET NOCOUNT ON 5jk4k c
DECLARE @LogicalFileName sysname, .U
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@MaxMinutes INT, 0\;a:E.c
@NewSize INT &"0[7zgYQz
USE tablename -- 要操作的数据库名 )Jn80~U|1
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 Q)8t;Kx
@MaxMinutes = 10, -- Limit on time allowed to wrap log. <:o><f+
@NewSize = 1 -- 你想设定的日志文件的大小(M) wAPdu y[
-- Setup / initialize );LwWKa
DECLARE @OriginalSize int PUArKBYM-
SELECT @OriginalSize = size zvg&o)/[
FROM sysfiles {S~$\4vC!
WHERE name = @LogicalFileName 2J <Z4Ap
SELECT 'Original Size of ' + db_name() + ' LOG is ' + Fb-TCq1y#
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + >iV(8EgBS
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' IA!Kpg
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FROM sysfiles EeJ]>
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WHERE name = @LogicalFileName ,iy
CREATE TABLE DummyTrans k$/].P*!
(DummyColumn char (8000) not null) <GEn9;\
DECLARE @Counter INT, BW[K/l~"$:
@StartTime DATETIME, jz0\F,s
@TruncLog VARCHAR(255) &Gl&m@-j
SELECT @StartTime = GETDATE(), }(6k7{,Gw,
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' .?
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) zvj\n9H
EXEC (@TruncLog) 06
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-- Wrap the log if necessary. QI<3N
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired WDR!e2G
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) $4]PN2d&
AND (@OriginalSize * 8 /1024) > @NewSize gd*?kXpt
BEGIN -- Outer loop. WdnP[x9
SELECT @Counter = 0 +UtK2<^:o
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) egvWPht'_
BEGIN -- update 9IV WbJ
INSERT DummyTrans VALUES ('Fill Log') ?i"FdpW
DELETE DummyTrans pj6Cvq4bD
SELECT @Counter = @Counter + 1 MIJ~j><L
END TMBdneS-s
EXEC (@TruncLog) I&c#U+-A'
END on$a]zx'@
SELECT 'Final Size of ' + db_name() + ' LOG is ' + nm.d.A/]Z
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + %{"STbO #>
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 4 vphLAm
FROM sysfiles Y'9deX+
WHERE name = @LogicalFileName g(^l>niF:
DROP TABLE DummyTrans )2S\:&x
SET NOCOUNT OFF DQ$/0bq
8、说明:更改某个表 V"XN(Fd^
exec sp_changeobjectowner 'tablename','dbo' ,8seoX^
9、存储更改全部表 ai RNd~\
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch ~r3g~MCHS
@OldOwner as NVARCHAR(128), mLO6`]p{H
@NewOwner as NVARCHAR(128) )ej8vm
AS `1gsrHi4N
DECLARE @Name as NVARCHAR(128) lVHJ}(<'p
DECLARE @Owner as NVARCHAR(128) WP9=@X Z
DECLARE @OwnerName as NVARCHAR(128) :C5N(x
DECLARE curObject CURSOR FOR 7_,X9^z
select 'Name' = name, crQuoOl7
'Owner' = user_name(uid) eNX-2S
from sysobjects 2NM}u\%c/
where user_name(uid)=@OldOwner ;a"Ukh
order by name YQOGxSi
OPEN curObject h?sh#j6
FETCH NEXT FROM curObject INTO @Name, @Owner v.MWO]L
WHILE(@@FETCH_STATUS=0) 4m:E:zVn
BEGIN vbp)/I-h
if @Owner=@OldOwner )C[8#Q-:
begin +]X^bB[
set @OwnerName = @OldOwner + '.' + rtrim(@Name) yI)2:Ca*
exec sp_changeobjectowner @OwnerName, @NewOwner v*pVcBY>
end RD^o&