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。 -5@hU8B'a
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一、基础 s^/2sjoL
1、说明:创建数据库 5oo6d4[
CREATE DATABASE database-name [2ri=lf,
2、说明:删除数据库 ;VbB]aUg
drop database dbname }*7Gq
3、说明:备份sql server 3w+ +F@(
--- 创建 备份数据的 device Gg%pU+'T
USE master ?_.
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EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' Pxgal4{6
--- 开始 备份 r|ogF8YN
BACKUP DATABASE pubs TO testBack x)f<lZ^L&H
4、说明:创建新表 DN;$->>
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 9+~1# |
根据已有的表创建新表: =27Z Y Z
A:create table tab_new like tab_old (使用旧表创建新表) '
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B:create table tab_new as select col1,col2... from tab_old definition only )2R]KU_=g
5、说明:删除新表 srH.$Y;~
drop table tabname Bd[H@oKru
6、说明:增加一个列 ZpZoOdjslV
Alter table tabname add column col type 1czU$!MV
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 sAjN<P
7、说明:添加主键: Alter table tabname add primary key(col) 6ciA|J'MR
说明:删除主键: Alter table tabname drop primary key(col) LWV^'B_X-
8、说明:创建索引:create [unique] index idxname on tabname(col....) 'r}y{`3M
删除索引:drop index idxname #y1M1O g
注:索引是不可更改的,想更改必须删除重新建。 Jjh=zxR>
9、说明:创建视图:create view viewname as select statement VgMuX3=
删除视图:drop view viewname 0kaMYV?
10、说明:几个简单的基本的sql语句 ^j<2s"S
选择:select * from table1 where 范围 }p*WH$!~
插入:insert into table1(field1,field2) values(value1,value2) M+7jJ?n
删除:delete from table1 where 范围 kMg[YQ]OC
更新:update table1 set field1=value1 where 范围 ZC)m&V1
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! `-5gsJ
排序:select * from table1 order by field1,field2 [desc] 35YDP|XZb
总数:select count as totalcount from table1 @ZtvpL}e
求和:select sum(field1) as sumvalue from table1 vSk1/
平均:select avg(field1) as avgvalue from table1 S0;s
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最大:select max(field1) as maxvalue from table1 cK'}+
最小:select min(field1) as minvalue from table1 ;>Z0e`=
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11、说明:几个高级查询运算词 ~2QD.(
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A: UNION 运算符 T!>sL=uf
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。 XKvH^Z4h{l
B: EXCEPT 运算符 x'V:qv*O
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。 y>ePCDR3
C: INTERSECT 运算符 .<6'*XR
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。 K pmq C$
注:使用运算词的几个查询结果行必须是一致的。 >eX 9dA3X
12、说明:使用外连接 cY.5z:7u~v
A、left outer join: 3GXmyo:o$
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。 aF.fd2k
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 I %CrsEo
B:right outer join: au/5`
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。 'Ge8l%p
C:full outer join: GsIqUM#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。 JY$;m3h
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二、提升 #X0Y8:vj
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 1c4:'0
法一:select * into b from a where 1<>1 %5j*e
法二:select top 0 * into b from a 2QKt.a
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用)
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insert into b(a, b, c) select d,e,f from b; E+Dcw
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 9M@,BXOt
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 @[]#[7
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. %4Yq
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4、说明:子查询(表名1:a 表名2:b) \Z-Fu=8J8^
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) ^[b DE0
5、说明:显示文章、提交人和最后回复时间 &cy<"y
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b Gl9,!"A
6、说明:外连接查询(表名1:a 表名2:b) I~,b ZA
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c _BG7JvI
7、说明:在线视图查询(表名1:a ) ~zQxfl/
select * from (SELECT a,b,c FROM a) T where t.a > 1; xU
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8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 {6>$w/+~
select * from table1 where time between time1 and time2 0_-P~^A
select a,b,c, from table1 where a not between 数值1 and 数值2 'v5q/l
9、说明:in 的使用方法 B\+uRiD8w
select * from table1 where a [not] in ('值1','值2','值4','值6') 18>v\Hi<
10、说明:两张关联表,删除主表中已经在副表中没有的信息 K8h\T4
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) W?du ]
11、说明:四表联查问题: JG{`tTu
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 ..... (dHjf;
12、说明:日程安排提前五分钟提醒 0+KSD{
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 2Vxx
13、说明:一条sql 语句搞定数据库分页 c;88Wb<|W
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 )<.y{_QUN
14、说明:前10条记录 vHb^@z=
select top 10 * form table1 where 范围 dAi.^! !
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.) WLCr ~r^
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 5X:3'*
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 STz@^A
(select a from tableA ) except (select a from tableB) except (select a from tableC) Raf-I+
17、说明:随机取出10条数据 -f"{%<Q
select top 10 * from tablename order by newid() /?*ut&hwv
18、说明:随机选择记录 &a'LOq+r'
select newid() ,vuC0{C^
19、说明:删除重复记录 j k&\{
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) @I?:x4
20、说明:列出数据库里所有的表名 HP:[aR!2P
select name from sysobjects where type='U' AL|3_+G
21、说明:列出表里的所有的 D{JwZL@7k2
select name from syscolumns where id=object_id('TableName') C4gzg
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。 ~Jlq.S'
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 Nf}i/
显示结果: }Zfi/ ^0U
type vender pcs L),bPfz
电脑 A 1 r"dR}S.Uf
电脑 A 1 *TPWLR ^
光盘 B 2 y8dOx=c
光盘 A 2 wqgKs=y
手机 B 3 hbs /S
手机 C 3 hd)WdGJp
23、说明:初始化表table1 DkW^gt
TRUNCATE TABLE table1 \+k~p:d_8
24、说明:选择从10到15的记录 vILgM\or
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc
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三、技巧 mv(/M
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1、1=1,1=2的使用,在SQL语句组合时用的较多 SME]C ')7
"where 1=1" 是表示选择全部 "where 1=2"全部不选, c,#Nd@
如: @[{5{ y
if @strWhere !='' rVp^s/A^;
begin +R"n_6N
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere IH.EvierJ
end f,ql8q(|J
else nI8zT0o
begin 1D%E})B6
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 8tzL.P^
end a >k9&
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我们可以直接写成 yGH')TsjD
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere +P.JiH`\=
2、收缩数据库 l`a_0
--重建索引 "e/"$z'ca
DBCC REINDEX =`l><
DBCC INDEXDEFRAG "+hUt
--收缩数据和日志 ovaX_d)cU
DBCC SHRINKDB 7H4kj7UK
DBCC SHRINKFILE \jAI~|3
3、压缩数据库 ,C|aiSh0-
dbcc shrinkdatabase(dbname) )))AxgM
4、转移数据库给新用户以已存在用户权限 {*nE8+..A
exec sp_change_users_login 'update_one','newname','oldname' X7?j90tH
go TV}=$\D
5、检查备份集 ^=qV)j
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' Omph(
6、修复数据库 ^}lL@Bd|
ALTER DATABASE [dvbbs] SET SINGLE_USER $SfY<j,R
GO c*R18,5-
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK >]2 ^5C;
GO [~?6jnp
ALTER DATABASE [dvbbs] SET MULTI_USER bG+Gg*0p
GO IEWl
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7、日志清除 LYTnMrM
SET NOCOUNT ON ^Zlbs
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DECLARE @LogicalFileName sysname, zR?1iV.]
@MaxMinutes INT, qipS`:TER
@NewSize INT {vur9L
USE tablename -- 要操作的数据库名 rym*W\AWx
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 #r]GnC,
@MaxMinutes = 10, -- Limit on time allowed to wrap log. C}\kp0mz
@NewSize = 1 -- 你想设定的日志文件的大小(M) !>Q{co'
-- Setup / initialize D2zqDo<+;
DECLARE @OriginalSize int wd1>L) T
SELECT @OriginalSize = size SRrp=>w?
FROM sysfiles ^[v>B@p*{
WHERE name = @LogicalFileName lo36b zbT
SELECT 'Original Size of ' + db_name() + ' LOG is ' + !"'@c
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + T7N\b]?j@Y
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ,QLy}=N
FROM sysfiles tR_DN
WHERE name = @LogicalFileName o_ r{cnu
CREATE TABLE DummyTrans ^$<:~qq!
(DummyColumn char (8000) not null) }{v0}-~@
DECLARE @Counter INT, 4 &0MB>m
@StartTime DATETIME, ,,-j5Y
@TruncLog VARCHAR(255) jI$7vmO
SELECT @StartTime = GETDATE(), ZL9|/
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@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ,.&D{$1W
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 3w! NTvp
EXEC (@TruncLog) z'0
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-- Wrap the log if necessary. S(: |S(
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Az/P;C=
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) [ *
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AND (@OriginalSize * 8 /1024) > @NewSize <<H'Z
BEGIN -- Outer loop. H-8_&E?6m
SELECT @Counter = 0 Htep3Ol3
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) 1h`# H:
BEGIN -- update fm Fs
INSERT DummyTrans VALUES ('Fill Log')
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DELETE DummyTrans Hq,znRz~`
SELECT @Counter = @Counter + 1 ;9qwB
END qnO/4\qq
EXEC (@TruncLog) 5'EoB^`8N~
END yaAg!mW
SELECT 'Final Size of ' + db_name() + ' LOG is ' + jjg&C9w T
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + w# ;t$qz}
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' l!IN #|{(
FROM sysfiles Ub[UB%(T
WHERE name = @LogicalFileName 6>h"Lsww
DROP TABLE DummyTrans XOEf,"
SET NOCOUNT OFF vQ[ TcV
8、说明:更改某个表 %}{.U
exec sp_changeobjectowner 'tablename','dbo' U)1hC^[!
9、存储更改全部表 =BzBM`-o
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch v=D4O .
@OldOwner as NVARCHAR(128), ^L'<%_#.
@NewOwner as NVARCHAR(128) u#0EZ2>#
AS j0S[JpoF
DECLARE @Name as NVARCHAR(128) ZOL#Q+U
DECLARE @Owner as NVARCHAR(128) z@2nre
DECLARE @OwnerName as NVARCHAR(128) <p[RhP
DECLARE curObject CURSOR FOR M*F`s&vM
select 'Name' = name, r6kQMFA
'Owner' = user_name(uid) N
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from sysobjects +sXnC\
where user_name(uid)=@OldOwner 07Oagq(
order by name ]jV1/vJ-!
OPEN curObject u<HJFGLzI
FETCH NEXT FROM curObject INTO @Name, @Owner [LS s|f
WHILE(@@FETCH_STATUS=0) qtp-w\#S$
BEGIN C(}Kfi@6N
if @Owner=@OldOwner Ky{C;7X
begin ] .c$(.
set @OwnerName = @OldOwner + '.' + rtrim(@Name) qwo{34
exec sp_changeobjectowner @OwnerName, @NewOwner ^0/!:*?
end kqLpt
-- select @name,@NewOwner,@OldOwner [O6JVXO>
FETCH NEXT FROM curObject INTO @Name, @Owner "mcuF]7F
END _61tE
close curObject [V;Q#r&+
deallocate curObject I5g!c|#y
GO M
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10、SQL SERVER中直接循环写入数据 {;hRFQ^b
declare @i int N ^H
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set @i=1 T7*p!0
while @i<30 M5+K[Ir/y9
begin j g_;pn
insert into test (userid) values(@i) (@xr/9:i
set @i=@i+1 h'A
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end |l,0bkY@&
小记存储过程中经常用到的本周,本月,本年函数 wE_#b\$=b
Dateadd(wk,datediff(wk,0,getdate()),-1) 9bD ER
Dateadd(wk,datediff(wk,0,getdate()),6) |LE*R@|3$
Dateadd(mm,datediff(mm,0,getdate()),0) ^2mCF
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) +VHoYEW
Dateadd(yy,datediff(yy,0,getdate()),0) _u;34H&/
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) !r+SE
上面的SQL代码只是一个时间段 }do=lm?/
Dateadd(wk,datediff(wk,0,getdate()),-1) UujKgL4
Dateadd(wk,datediff(wk,0,getdate()),6) G3t\2E9S
就是表示本周时间段. C6:;
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下面的SQL的条件部分,就是查询时间段在本周范围内的: ra{HlB{
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) -[7S.
而在存储过程中 h>n<5{zqM
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) xQ8?"K;iX
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) \eS-wO7%