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。 4)odFq:
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一、基础 KI Plb3oh
1、说明:创建数据库 fY%M=,t3c
CREATE DATABASE database-name Q@e*$<3
2、说明:删除数据库 jV4hxuc$
drop database dbname BbXU|QtY
3、说明:备份sql server $d2kHT
--- 创建 备份数据的 device l~fh_IV1
USE master QxL@'n#5
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' '"xL}8HX}
--- 开始 备份 M2;%1^
BACKUP DATABASE pubs TO testBack OK
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4、说明:创建新表 )RA\kZ "
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) |6sT,/6
根据已有的表创建新表: =GH@.3`X
A:create table tab_new like tab_old (使用旧表创建新表) J@ktj(
B:create table tab_new as select col1,col2... from tab_old definition only Q/QQ:t<XUi
5、说明:删除新表 7wiK.99
drop table tabname ?#BZ `H
6、说明:增加一个列 to!mz\F
Alter table tabname add column col type q,;".3VQ
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。 <TLGfA1bC
7、说明:添加主键: Alter table tabname add primary key(col) $ DDSN
说明:删除主键: Alter table tabname drop primary key(col) W+d9cM=
8、说明:创建索引:create [unique] index idxname on tabname(col....) qeQC&U
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删除索引:drop index idxname FylWbQU9
注:索引是不可更改的,想更改必须删除重新建。 VD9
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9、说明:创建视图:create view viewname as select statement #$rf-E5g-K
删除视图:drop view viewname G *mO&:q
10、说明:几个简单的基本的sql语句 ~:/%/-^
选择:select * from table1 where 范围 '?{0z!!
插入:insert into table1(field1,field2) values(value1,value2) :S QDqG
删除:delete from table1 where 范围 Exep+x-
更新:update table1 set field1=value1 where 范围 TnN^2:cU
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! wUru1_zjO
排序:select * from table1 order by field1,field2 [desc] ?G4iOiyt
总数:select count as totalcount from table1 ur/Oc24i1n
求和:select sum(field1) as sumvalue from table1 F-$Z,Q]S
平均:select avg(field1) as avgvalue from table1 9nng}em>.
最大:select max(field1) as maxvalue from table1 Wk/fB0
最小:select min(field1) as minvalue from table1 eZ!yPdgy|
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11、说明:几个高级查询运算词 I$aXnd6)
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A: UNION 运算符 H<V+d^qX\w
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 `xISkW4 %
B: EXCEPT 运算符 8_"3Yb`f
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 PzIy">plm
C: INTERSECT 运算符 &e%{k@
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 m3U+ du
注:使用运算词的几个查询结果行必须是一致的。 E/:+@'(k
12、说明:使用外连接 Qe2m8
A、left outer join: rU;
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左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 SW3wMPy&s
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c /t$rX3A
B:right outer join: ~J%R-{U9
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。 jZa25Z00
C:full outer join: "(0oP9lZ
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。 C}Rs[
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二、提升 "w;08TX8
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) K1;zMh
法一:select * into b from a where 1<>1 NV:>a
法二:select top 0 * into b from a Lqg]Fd
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) b+W)2rFO
insert into b(a, b, c) select d,e,f from b; nARxn#<+
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) :[L{KFQU
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 F\;2i:(
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. !)NYW4"
4、说明:子查询(表名1:a 表名2:b) Z/xV\Ggx
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) Po!oN~r
5、说明:显示文章、提交人和最后回复时间 7Aqn[1{_O
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b
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6、说明:外连接查询(表名1:a 表名2:b) GNs#oM
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c y^9bfMA
7、说明:在线视图查询(表名1:a ) +IvNyj|
select * from (SELECT a,b,c FROM a) T where t.a > 1; <sa #|Y$
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 jh>N_cp
select * from table1 where time between time1 and time2 NK 8<=
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select a,b,c, from table1 where a not between 数值1 and 数值2 N"S3N)wgd
9、说明:in 的使用方法 w(/7Jt$
select * from table1 where a [not] in ('值1','值2','值4','值6') HHZ`%
10、说明:两张关联表,删除主表中已经在副表中没有的信息 9p5= _
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) _0w1kqW
11、说明:四表联查问题: VXiui'/(
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 ..... Bu&So|@TL
12、说明:日程安排提前五分钟提醒 -jFP7tEv
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 b,9@P&=:2
13、说明:一条sql 语句搞定数据库分页 CdZnD#F2
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
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14、说明:前10条记录 )GK+
select top 10 * form table1 where 范围 (/-lV&eR
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.)
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select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) tp@*=*^I
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 lHcA j{6
(select a from tableA ) except (select a from tableB) except (select a from tableC) VXA[TIqp
17、说明:随机取出10条数据 HV8I nodi
select top 10 * from tablename order by newid() ^1R"7h
18、说明:随机选择记录 *u}'}jC1X
select newid() 7q!?1 -?8R
19、说明:删除重复记录 |4Qx=x>
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) B4IBuS
20、说明:列出数据库里所有的表名 M%3Wy"YQ,n
select name from sysobjects where type='U' ubi~%
21、说明:列出表里的所有的 @$oZ|ZkZ
select name from syscolumns where id=object_id('TableName') J||E;=%f-Q
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。 "sD1T3!\)Q
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 wE?CvL
显示结果: >:%BNeO
type vender pcs 02(h={
电脑 A 1 YKY2Cw
电脑 A 1 S#mK
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光盘 B 2 g>_OuQ|c
光盘 A 2 5?w.rcN[j
手机 B 3 ;?zF6zvQ
手机 C 3 a_MFQf&KV
23、说明:初始化表table1 3-iD.IAUm@
TRUNCATE TABLE table1 XC2FF&B&
24、说明:选择从10到15的记录 8TW5(fl
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc &sdx`,
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三、技巧 x)_r@l`$ix
1、1=1,1=2的使用,在SQL语句组合时用的较多 J0sGvj{
"where 1=1" 是表示选择全部 "where 1=2"全部不选, l~D\;F
如: F\-Si!~oOz
if @strWhere !='' e^8BV;+c
begin }vY.EEy!
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere `c9'0*-
end <aXoB*Y
else 2T?TM! \Q
begin `BjR.xMv
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' WL1\y|
end '60//"9>k/
我们可以直接写成 m]P/if7
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere <h@]Ri
2、收缩数据库 GyK(Vb"h6
--重建索引 -?z\5z
DBCC REINDEX JD*8@N
DBCC INDEXDEFRAG 3ev -Iqz
--收缩数据和日志 WqQU@sA
DBCC SHRINKDB iZ "y7s
DBCC SHRINKFILE r^5jh1
3、压缩数据库 |IN[uQ
dbcc shrinkdatabase(dbname) 6.19g'{sB
4、转移数据库给新用户以已存在用户权限 X}W)3v
exec sp_change_users_login 'update_one','newname','oldname' ?oKL&I@
go V%51k{
5、检查备份集 Mq'IkSt'
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' jT-<IJh!o
6、修复数据库 ]2$x|#Gg}
ALTER DATABASE [dvbbs] SET SINGLE_USER oM-[B h]A
GO ,H{={aln
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ,v7Q *3
GO d.AC%&W
ALTER DATABASE [dvbbs] SET MULTI_USER F 7LiG9H6`
GO hZU1O
7、日志清除 :tbd,Uo
SET NOCOUNT ON CA*~2|
DECLARE @LogicalFileName sysname, 6|#g+&[
@MaxMinutes INT, H+x#gK2l
@NewSize INT YlKFw|=
USE tablename -- 要操作的数据库名
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SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 YtYy zX5u7
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ?1w"IjUS
@NewSize = 1 -- 你想设定的日志文件的大小(M) "
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-- Setup / initialize vyU!+mlc
DECLARE @OriginalSize int IaasHo\
SELECT @OriginalSize = size O{q&]~,
FROM sysfiles !*vBW/
WHERE name = @LogicalFileName r?3Aqi"
SELECT 'Original Size of ' + db_name() + ' LOG is ' + H~Uq?!=b
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + P
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' bVK$.*,
FROM sysfiles IU9,
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WHERE name = @LogicalFileName (p,}'I#i*
CREATE TABLE DummyTrans B*79qq
(DummyColumn char (8000) not null) eY}V9*.v
DECLARE @Counter INT, @i1q]0
@StartTime DATETIME, 1<,/
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@TruncLog VARCHAR(255) A*i_|]Q
SELECT @StartTime = GETDATE(), ^yVl"/
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' N!c
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) %5Rq1 $D
EXEC (@TruncLog) 9@y3IiZ"}
-- Wrap the log if necessary. {Hk/1KG>
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired yL&/m~{s
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) Ac\W\=QvB
AND (@OriginalSize * 8 /1024) > @NewSize RL&lKHA
BEGIN -- Outer loop. z_l. V/G)
SELECT @Counter = 0 GV6mzD@<
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) Ekjf^Uo
BEGIN -- update ;J=:IEk
INSERT DummyTrans VALUES ('Fill Log') Xw^X&Pp
DELETE DummyTrans
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SELECT @Counter = @Counter + 1 1VLLo~L%
END D^$OCj\
EXEC (@TruncLog) p+<}YDMb
END L_?$ayZ;
SELECT 'Final Size of ' + db_name() + ' LOG is ' + %h/! Y<%
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + TSQhX~RN
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' t?3BCm$Mi
FROM sysfiles
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WHERE name = @LogicalFileName qjLo&2)
DROP TABLE DummyTrans p(?3
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SET NOCOUNT OFF /b{HG7i\
8、说明:更改某个表 y<M]dd$
exec sp_changeobjectowner 'tablename','dbo' .Dx2 ;lj
9、存储更改全部表 I?M@5u
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch fl)zQcA
@OldOwner as NVARCHAR(128), Yi Zx{5
@NewOwner as NVARCHAR(128) N-QCfDao
AS fU
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DECLARE @Name as NVARCHAR(128) oAz<G
DECLARE @Owner as NVARCHAR(128) %nQmFIt
DECLARE @OwnerName as NVARCHAR(128) a))*F!}c
DECLARE curObject CURSOR FOR H,|YLKg-|
select 'Name' = name, nh;y:Bi
'Owner' = user_name(uid) Qlh?iA
from sysobjects Fu##'#
where user_name(uid)=@OldOwner usH%dzKK
order by name ^Y 7U1I
OPEN curObject CQ1 8%w6
FETCH NEXT FROM curObject INTO @Name, @Owner 0b++17aV
WHILE(@@FETCH_STATUS=0) s<VJ`Ur
BEGIN =|V"#3$f
if @Owner=@OldOwner hr~.Lj5^W
begin 5/(sjMB
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 'tuBuYD\
exec sp_changeobjectowner @OwnerName, @NewOwner o9+Q{|r
end [*HiI=
-- select @name,@NewOwner,@OldOwner #90c$ dc
FETCH NEXT FROM curObject INTO @Name, @Owner "dq>)JF\
END FG#nap{
close curObject <<<NXsH
deallocate curObject vZk9gGjk
GO {(0Id !
10、SQL SERVER中直接循环写入数据 K?YEoz'y[
declare @i int -TZ^ ~s
set @i=1 Gh+f1)\FA"
while @i<30 a7*COh
begin xB,/dMdTj
insert into test (userid) values(@i) U'M|=I'
set @i=@i+1 e^WqJ7j
end O!
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小记存储过程中经常用到的本周,本月,本年函数 Ql8^]gbp+
Dateadd(wk,datediff(wk,0,getdate()),-1) K0 QH?F
Dateadd(wk,datediff(wk,0,getdate()),6) }VZM,.w
Dateadd(mm,datediff(mm,0,getdate()),0) #[(gIOrNn8
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0))
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Dateadd(yy,datediff(yy,0,getdate()),0) i'iO H|s
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) -;ER`Jqs,
上面的SQL代码只是一个时间段 Y{j7Q4{
Dateadd(wk,datediff(wk,0,getdate()),-1) "$P'Wv
Dateadd(wk,datediff(wk,0,getdate()),6) P
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就是表示本周时间段. )r#,ML
下面的SQL的条件部分,就是查询时间段在本周范围内的: '}CN?f|.
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) pJocI_v9
而在存储过程中 8=pv/o
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) KG-y)qXu
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) lJlhl7