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。 XUw/2"D'?
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一、基础 .~}1+\~5
1、说明:创建数据库 'RRE|L,
CREATE DATABASE database-name }75e:w[
2、说明:删除数据库 =2 kG%9
drop database dbname nOz.G"
3、说明:备份sql server 'QIqBU'~
--- 创建 备份数据的 device |CzSU1ma
USE master 03(4 x'z
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' \4#W xZ
--- 开始 备份 E P+J
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BACKUP DATABASE pubs TO testBack Rh |nP&6
4、说明:创建新表
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create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) bTu9;(
根据已有的表创建新表: yZ`wfj$Jj
A:create table tab_new like tab_old (使用旧表创建新表) Y<rU#Z #T
B:create table tab_new as select col1,col2... from tab_old definition only Uwi7)
5、说明:删除新表 q]M0md
drop table tabname X76e&~
6、说明:增加一个列 ]tDDq=+v
Alter table tabname add column col type ~,~eoW7
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 k'"%.7$U!
7、说明:添加主键: Alter table tabname add primary key(col) {GO#.P"
说明:删除主键: Alter table tabname drop primary key(col) +{UcspqM
8、说明:创建索引:create [unique] index idxname on tabname(col....) x;')9/3
删除索引:drop index idxname qv*^fiT
注:索引是不可更改的,想更改必须删除重新建。 e]tDy0@
9、说明:创建视图:create view viewname as select statement 7=DdrG<
删除视图:drop view viewname >U3cTEs cj
10、说明:几个简单的基本的sql语句 `p7=t)5k
选择:select * from table1 where 范围 V!dtF,tH
插入:insert into table1(field1,field2) values(value1,value2) 5Dl/aHb
删除:delete from table1 where 范围 2|bn(QYz
更新:update table1 set field1=value1 where 范围 u4_9)P`]0
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! WT}H>T
排序:select * from table1 order by field1,field2 [desc] ``Un&-Ms
总数:select count as totalcount from table1 L^Fy#p
求和:select sum(field1) as sumvalue from table1 (M
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平均:select avg(field1) as avgvalue from table1 1r7y]FyH$
最大:select max(field1) as maxvalue from table1 [sb[Z:
最小:select min(field1) as minvalue from table1 MxGW(p
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11、说明:几个高级查询运算词 @gtQQxf"
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A: UNION 运算符 FEVlZ<PW3I
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。 Wr5V`sM
B: EXCEPT 运算符 -R6)ROGl
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。 z"4~P3>{g
C: INTERSECT 运算符 #!m.!?
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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。 (3&?w y_l
注:使用运算词的几个查询结果行必须是一致的。 -)/$M(Pu"
12、说明:使用外连接 h65-s
A、left outer join: -Vhw^T1iV
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 uOGw9O-d9
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ilva,WFa^
B:right outer join: fg{n(TE"8
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 W"3ph6[eW
C:full outer join: "x /OIf
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 _Y[bMuUb=
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二、提升 O,A{3DAe0
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ~3S~\0&|
法一:select * into b from a where 1<>1 H$KTo/
法二:select top 0 * into b from a i@R
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) c7E11 \%&Z
insert into b(a, b, c) select d,e,f from b; 'XBFv9&
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) 3<zp
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 *
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例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. IyPnp&_
4、说明:子查询(表名1:a 表名2:b) D#/Bx[
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) I,'k>@w{s
5、说明:显示文章、提交人和最后回复时间 Q?/o%`N
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b UEVG0qF
6、说明:外连接查询(表名1:a 表名2:b) 63~
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select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 9?3&?i2-
7、说明:在线视图查询(表名1:a ) <V6VMYXY4
select * from (SELECT a,b,c FROM a) T where t.a > 1; wsVV$I[2
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 @{pLk4E
select * from table1 where time between time1 and time2 :$9tF>
select a,b,c, from table1 where a not between 数值1 and 数值2 2Q"K8=s
9、说明:in 的使用方法 E\2%E@0#
select * from table1 where a [not] in ('值1','值2','值4','值6') PIpi1v*qz
10、说明:两张关联表,删除主表中已经在副表中没有的信息 {&T_sw@[
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ^Js9 s8?$
11、说明:四表联查问题: b,%C{mC
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 ..... +XYE {E5
12、说明:日程安排提前五分钟提醒 ")HFYqP>9
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 ~<OSYb
13、说明:一条sql 语句搞定数据库分页 x~j`@k,;
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 oFGhNk
14、说明:前10条记录 {s{j~M
select top 10 * form table1 where 范围 !1Cy$}w
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) x7x\Y(@
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) *GN#
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16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 Clb@$,
(select a from tableA ) except (select a from tableB) except (select a from tableC) 5RpjN: 3
17、说明:随机取出10条数据 H&}pkrH~
select top 10 * from tablename order by newid() ZEO,]$Yi7
18、说明:随机选择记录 =k:,qft2
select newid() ,$+V
19、说明:删除重复记录 yN
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Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) [bNx^VP*
20、说明:列出数据库里所有的表名 bB;5s`-
select name from sysobjects where type='U' 3K/MvNI>
21、说明:列出表里的所有的 ^_5r<{7/ :
select name from syscolumns where id=object_id('TableName') 1s@+;QUib
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。 3fJc
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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 @<]Ekkg
显示结果: h@WhNk7"xa
type vender pcs ">jj
电脑 A 1 {Wu$YWE*sx
电脑 A 1 SrK<fAkx
光盘 B 2 ye? 'Ze
光盘 A 2 XJ5.
手机 B 3 rkY[E(SY
手机 C 3 A;|D:;x3G
23、说明:初始化表table1 %zw1}|s#z
TRUNCATE TABLE table1 ;H.^i|_/
24、说明:选择从10到15的记录 ZH)="qx[
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc JNUt$h
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三、技巧 f/Bp.YwL
1、1=1,1=2的使用,在SQL语句组合时用的较多 t=O8f5Pf{
"where 1=1" 是表示选择全部 "where 1=2"全部不选, be^6i:
如: 9lH?-~9
if @strWhere !='' ce3YCflt
begin gH7|=W
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere WoRZW%
end N;j)k;
else "s_lP&nq
begin -JjM y X
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 2nIw7>.}f
end Jh[UtYb5
我们可以直接写成 GMl;7?RA
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere K8.!_
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2、收缩数据库 :#?5X|Gz
--重建索引 dg"3rs /?A
DBCC REINDEX J9iy
DBCC INDEXDEFRAG X;c'[q
--收缩数据和日志 o/Q;f@
DBCC SHRINKDB 6N
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DBCC SHRINKFILE O[)kboY
3、压缩数据库 K]"#C
dbcc shrinkdatabase(dbname) [ )dXI IM
4、转移数据库给新用户以已存在用户权限 JU5C}%Q6
exec sp_change_users_login 'update_one','newname','oldname' 28J^DMOW
go hP)LY=-2
5、检查备份集 G&V/Gj8
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' )vb*Ef
6、修复数据库 > eIP.,9
ALTER DATABASE [dvbbs] SET SINGLE_USER YCM]VDx4u1
GO #c?j\Y9nz
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK f-n1I^|
GO *8_wYYH
ALTER DATABASE [dvbbs] SET MULTI_USER R1GEh&U{
GO 4X
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7、日志清除 | Aw%zw1@
SET NOCOUNT ON
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DECLARE @LogicalFileName sysname, t+iHQfuP9A
@MaxMinutes INT, %H&@^Tt a
@NewSize INT $!yW_HTx
USE tablename -- 要操作的数据库名 1@1U/ss1
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 474SMx$
@MaxMinutes = 10, -- Limit on time allowed to wrap log. usCt#eZK
@NewSize = 1 -- 你想设定的日志文件的大小(M) 4 k _vdz
-- Setup / initialize .QJ5sgmh
DECLARE @OriginalSize int YLv'43PL
SELECT @OriginalSize = size es&vMY
FROM sysfiles |O9O )o
WHERE name = @LogicalFileName }h!f eP
SELECT 'Original Size of ' + db_name() + ' LOG is ' + f;gw"onx8F
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + T<p !5`B 1
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' EYEnN
FROM sysfiles h+&OQ%e=8
WHERE name = @LogicalFileName `FTy+8mw
CREATE TABLE DummyTrans DBD%6o>]K
(DummyColumn char (8000) not null)
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DECLARE @Counter INT, D9
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@StartTime DATETIME, ?!cvf{a
@TruncLog VARCHAR(255) 9Ujo/3,Ak
SELECT @StartTime = GETDATE(), [8,yF
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@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' #32"=MfQn
DBCC SHRINKFILE (@LogicalFileName, @NewSize) -pGE]nwDL
EXEC (@TruncLog) Y>G@0r BG
-- Wrap the log if necessary. ,TN
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 72y0/FJ
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) z>Hgkp8D"
AND (@OriginalSize * 8 /1024) > @NewSize 1Y@Aixx
BEGIN -- Outer loop. Qqvihd
SELECT @Counter = 0 W!&'pg
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ^_u kLzP9
BEGIN -- update 48qV>Gwf
INSERT DummyTrans VALUES ('Fill Log') \6<=$vD
DELETE DummyTrans M
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SELECT @Counter = @Counter + 1 sy"^?th}b
END xt%7@/hiE
EXEC (@TruncLog) L3 --r
END C=It* j55
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 7/f3Z1g
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + G) 7;;
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' TbGn46!:
FROM sysfiles Dg?70v<a
WHERE name = @LogicalFileName WDPb!-VT
DROP TABLE DummyTrans .my0|4CQ#@
SET NOCOUNT OFF |>htvDL
8、说明:更改某个表 LBsluT
exec sp_changeobjectowner 'tablename','dbo' Vz~nT
9、存储更改全部表 (Cd\G=PK
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch
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@OldOwner as NVARCHAR(128), s4SG[w!d
@NewOwner as NVARCHAR(128) 9qz6]-K
AS 7~aM=8r
DECLARE @Name as NVARCHAR(128) I@%t.%O Jp
DECLARE @Owner as NVARCHAR(128) #Xb+`'
DECLARE @OwnerName as NVARCHAR(128) &<J[Q%2
DECLARE curObject CURSOR FOR WIf0z#JMJm
select 'Name' = name, 2hkRd>)&5
'Owner' = user_name(uid) 5>j)kx=J9
from sysobjects 6qaQ[XTxf
where user_name(uid)=@OldOwner TAF
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order by name J}+6UlD
OPEN curObject "a1n_>#Fb
FETCH NEXT FROM curObject INTO @Name, @Owner 6&l+0dq
WHILE(@@FETCH_STATUS=0) &LVn6zAba
BEGIN j eX^}]x|%
if @Owner=@OldOwner 3]UUG
begin RUT,Y4 b
set @OwnerName = @OldOwner + '.' + rtrim(@Name) U,q\emR
exec sp_changeobjectowner @OwnerName, @NewOwner 7C ,UDp|
end .wu
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-- select @name,@NewOwner,@OldOwner M:3h e
FETCH NEXT FROM curObject INTO @Name, @Owner }36QsH8
END :1^R9yWA4
close curObject A"D,Kg
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deallocate curObject b7tOo7a H)
GO )'%$V%9
10、SQL SERVER中直接循环写入数据 [4C:r!
declare @i int #K Xa&C
set @i=1 ;b(p=\i
while @i<30 ,%Up0Rr,
begin MP 2~;T}~
insert into test (userid) values(@i) "7V2lu
set @i=@i+1 ~-m "
end \z7SkZt,GT
小记存储过程中经常用到的本周,本月,本年函数 fCtPu08{Z
Dateadd(wk,datediff(wk,0,getdate()),-1) <-S%kA8
Dateadd(wk,datediff(wk,0,getdate()),6) J@X'PG<
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Dateadd(mm,datediff(mm,0,getdate()),0) ";Rtiiu
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) $8[r9L!
Dateadd(yy,datediff(yy,0,getdate()),0) e9[|!/./5
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 5qoSEI-m
上面的SQL代码只是一个时间段 ANSFdc
Dateadd(wk,datediff(wk,0,getdate()),-1) F>[,zN
Dateadd(wk,datediff(wk,0,getdate()),6) ;Uu(zhbj
就是表示本周时间段. me ks
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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: ),!;| bh
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) F[[TWf/
而在存储过程中 GF%314Xu
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) I{:(z3
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) .j>hI="b