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。 "aHA6zTB
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一、基础 Cwl#(;@
1、说明:创建数据库 0& 54xP
CREATE DATABASE database-name w|7<y8#qC
2、说明:删除数据库 jw]~g+x#$
drop database dbname l*rli[No
3、说明:备份sql server D=i)AZqMPp
--- 创建 备份数据的 device y
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USE master hKj"Lb9]
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' Tapj7/0`
--- 开始 备份 %3!DRz
BACKUP DATABASE pubs TO testBack fo@2@
4、说明:创建新表 0
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create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) Yjx*hv&?
根据已有的表创建新表: kO>F, M
A:create table tab_new like tab_old (使用旧表创建新表) .IXkdy
B:create table tab_new as select col1,col2... from tab_old definition only |]y]K%
5、说明:删除新表 v!JQ;OX
drop table tabname bdEc?
6、说明:增加一个列 8bd&XieE
Alter table tabname add column col type $9)| cO
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 'tm%3`
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7、说明:添加主键: Alter table tabname add primary key(col) WW\t<O;z
说明:删除主键: Alter table tabname drop primary key(col) k` cz$>
8、说明:创建索引:create [unique] index idxname on tabname(col....) :+: vBrJm
删除索引:drop index idxname eD2u!OKW!
注:索引是不可更改的,想更改必须删除重新建。 [oqb@J2
9、说明:创建视图:create view viewname as select statement =^#^Mq)
删除视图:drop view viewname b;A(6^V
10、说明:几个简单的基本的sql语句 .Lbu[
选择:select * from table1 where 范围 c0h:Vqk-
插入:insert into table1(field1,field2) values(value1,value2) ?B7n,!&~
删除:delete from table1 where 范围 9x$Kb7'F
更新:update table1 set field1=value1 where 范围 uY{V^c#mv
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! j+YA/54`
排序:select * from table1 order by field1,field2 [desc] ,e<(8@BBL
总数:select count as totalcount from table1 @
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求和:select sum(field1) as sumvalue from table1 8&+m5xS
平均:select avg(field1) as avgvalue from table1 OiAP%7i9
最大:select max(field1) as maxvalue from table1 *c9/ I
最小:select min(field1) as minvalue from table1 ruiAEC<Ej
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11、说明:几个高级查询运算词 d)d\h`=Z
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A: UNION 运算符
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UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 tgz
B: EXCEPT 运算符 <Wqk5mR
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 bLSXQStB
C: INTERSECT 运算符 N{rC#A3
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 8Evon&G59
注:使用运算词的几个查询结果行必须是一致的。 4K{<R!2I
12、说明:使用外连接 1HPYW7jk@"
A、left outer join: <e)5$Aj
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。 St 4YNS.|
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 O{@m ,uY
B:right outer join: ,j^z];
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。 0H;,~
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C:full outer join: _\mMgZu
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。 EkWipF(
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二、提升 hqr V {c
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) )3 C~kmN7
法一:select * into b from a where 1<>1 ur*@TIvD
法二:select top 0 * into b from a 0uZ 'j
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) e[`u:
insert into b(a, b, c) select d,e,f from b; t>]wWYy
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) 8}5dyn{cvE
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 pyvZ[R9
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. +=Xgi$
4、说明:子查询(表名1:a 表名2:b) $mS]K!\
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) AL(YQ)-Cg
5、说明:显示文章、提交人和最后回复时间 UBN^dbP*
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b /d<"{\o
6、说明:外连接查询(表名1:a 表名2:b) 7*D*nY4+
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 1a|Z !Vzi
7、说明:在线视图查询(表名1:a ) Xn<~ln
select * from (SELECT a,b,c FROM a) T where t.a > 1; 2`|1 !x
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 Ujw J}j
select * from table1 where time between time1 and time2 e7fA-,DV
select a,b,c, from table1 where a not between 数值1 and 数值2 g`('
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9、说明:in 的使用方法 Y6J7N^
select * from table1 where a [not] in ('值1','值2','值4','值6') HC'k81Q
10、说明:两张关联表,删除主表中已经在副表中没有的信息 Uwd^%x*
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 2d%j6D
11、说明:四表联查问题: gc%aaYf>
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 ..... F.nJXZnJ
12、说明:日程安排提前五分钟提醒 o\Ocu>:
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 WGxe3(d
13、说明:一条sql 语句搞定数据库分页 [8T
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 m%mA0r
14、说明:前10条记录 d~lB4
select top 10 * form table1 where 范围 BC/oh+FW3
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.) 1r %~Rm
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) H*SEzVb
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 rkp 1tv
(select a from tableA ) except (select a from tableB) except (select a from tableC) bC[TLsh7{2
17、说明:随机取出10条数据 %j
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select top 10 * from tablename order by newid() >,ThIwRN
18、说明:随机选择记录 +@:$7m(V
select newid() #1>DV@^F
19、说明:删除重复记录 q(N2#di
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) |sa{!tKJ
20、说明:列出数据库里所有的表名 NS^(5g
select name from sysobjects where type='U' uU&,KEH
21、说明:列出表里的所有的 pI__<
select name from syscolumns where id=object_id('TableName')
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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。 '/Y
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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 j\,HquTR
显示结果: 37#|X*L
type vender pcs KK}?x6wV0,
电脑 A 1 7N@4c
电脑 A 1 ~j1.;WId[
光盘 B 2 $]&0`F
光盘 A 2 }Pu|%\
手机 B 3 1pT
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手机 C 3 BE&P/~(C
23、说明:初始化表table1 I=N;F6
TRUNCATE TABLE table1 bu;3Ib3\
24、说明:选择从10到15的记录 XDtr{r6z
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc d+
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三、技巧 1x\Vz\
1、1=1,1=2的使用,在SQL语句组合时用的较多 M5mCG
"where 1=1" 是表示选择全部 "where 1=2"全部不选, .GJl@==~1
如: R"j6 w[tn
if @strWhere !='' y:FxX8S$'e
begin ER z@o_
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere w"-'
end q\PHA
else DXbzl
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begin eSV_.uvsb
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' [1I>Bc&o*
end (r&e|
我们可以直接写成 QuJ~h}k
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere {nyQ]Nu"
2、收缩数据库 XIv{jzgF
--重建索引 GCw<jHw
DBCC REINDEX 1
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DBCC INDEXDEFRAG UfE41el:
--收缩数据和日志 f
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DBCC SHRINKDB q&eUw<(F
DBCC SHRINKFILE M<f=xY2$v
3、压缩数据库 "8pfLI
dbcc shrinkdatabase(dbname) D.e4S6\&
4、转移数据库给新用户以已存在用户权限 UV ?.KVD~
exec sp_change_users_login 'update_one','newname','oldname' x#mZSSd
go S C'F,!
5、检查备份集 |!0R"lv'u
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 5H+S=
6、修复数据库 .Yl*kG6r
ALTER DATABASE [dvbbs] SET SINGLE_USER AR<'Airi:
GO j Hd <*
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK %h"+J
GO 6bL"Z OEu
ALTER DATABASE [dvbbs] SET MULTI_USER 9*?H/iN@p?
GO T<p,KqH
7、日志清除 B{ i5UhxD
SET NOCOUNT ON W]8tp@
DECLARE @LogicalFileName sysname, 9!XW):
@MaxMinutes INT, =c)O8
@NewSize INT won(HK\1p
USE tablename -- 要操作的数据库名 Ov
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SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 >s@6rNgf
@MaxMinutes = 10, -- Limit on time allowed to wrap log. Cm4$&?
@NewSize = 1 -- 你想设定的日志文件的大小(M) X%S9H^9
-- Setup / initialize NXAP=y3
DECLARE @OriginalSize int .3(=UQ
SELECT @OriginalSize = size >E;&SX
FROM sysfiles S #M<d~rK
WHERE name = @LogicalFileName (7P{k<5
SELECT 'Original Size of ' + db_name() + ' LOG is ' + a '/yN{?p
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 69Y>iPRU
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' @IaK:
FROM sysfiles x;RjLI 4h
WHERE name = @LogicalFileName G$ l>By
CREATE TABLE DummyTrans 6B4s6
(DummyColumn char (8000) not null) vXUrS+~x
DECLARE @Counter INT, XxW~4<r
@StartTime DATETIME, (t.pM P4
@TruncLog VARCHAR(255) yFt'<{z[nL
SELECT @StartTime = GETDATE(), cZ(7/Pl
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY'
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) st;.Po[h
EXEC (@TruncLog) dXKv"*7l
-- Wrap the log if necessary. Dh*>361y-
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired GHQa{@m2V
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) nwd
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AND (@OriginalSize * 8 /1024) > @NewSize :K!@zT=o
BEGIN -- Outer loop. @@U'I^iG
SELECT @Counter = 0 >\Qyg>Md]
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) WMB~?
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BEGIN -- update JwzA'[tM
INSERT DummyTrans VALUES ('Fill Log') w%,Iy,G@
DELETE DummyTrans tS2 P|fl
SELECT @Counter = @Counter + 1 ]xf
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END 7y",%WYSD
EXEC (@TruncLog) Qtmsk:qm
END ~%Y*2i
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SELECT 'Final Size of ' + db_name() + ' LOG is ' + K5x&:z
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + PI7M3\z
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 8aw'Q?
FROM sysfiles -\;x>=#B
WHERE name = @LogicalFileName e![|-m%
DROP TABLE DummyTrans dQ*3s>B[
SET NOCOUNT OFF whW"cFg
8、说明:更改某个表 f"h{se8C
exec sp_changeobjectowner 'tablename','dbo' a;p3Me7
9、存储更改全部表 F+vgkqs@9
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch HYgq@47$[
@OldOwner as NVARCHAR(128), A"S{W^iL
@NewOwner as NVARCHAR(128) 6MfjB@
AS `0+zF-
DECLARE @Name as NVARCHAR(128) P,Fs7
DECLARE @Owner as NVARCHAR(128) Aa*UV6(v
DECLARE @OwnerName as NVARCHAR(128) 3@e#E4+ff
DECLARE curObject CURSOR FOR !+T9NqDv[
select 'Name' = name, wi]|"\
'Owner' = user_name(uid) kV7c\|N9
from sysobjects &3VR)Bxn
where user_name(uid)=@OldOwner o.5w>l!9K
order by name #uNQ+US0
OPEN curObject c ?mCt0Cg
FETCH NEXT FROM curObject INTO @Name, @Owner Bb];qYuCO
WHILE(@@FETCH_STATUS=0) .bbl-a/
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BEGIN BH0@WG7F
if @Owner=@OldOwner \AOVdnM:
begin DSyfF&uC
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 4{rwNBj(
exec sp_changeobjectowner @OwnerName, @NewOwner m#+0uZm(
end <`EZ^S L;
-- select @name,@NewOwner,@OldOwner %&bO+$H3
FETCH NEXT FROM curObject INTO @Name, @Owner F9q<MTh
END &1:xY.Zs_
close curObject :)+|q
deallocate curObject *]%{ttR~
GO X)d7y
10、SQL SERVER中直接循环写入数据 ysA~Nq@
declare @i int * a xOen
set @i=1 XW6Ewrm=vT
while @i<30 Y5fwmH,a-
begin
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insert into test (userid) values(@i) AW@I,
set @i=@i+1 W?8 |h
end 0_Tr>hz
小记存储过程中经常用到的本周,本月,本年函数 <5MnF
Dateadd(wk,datediff(wk,0,getdate()),-1) +)Tt\Q%7
Dateadd(wk,datediff(wk,0,getdate()),6) hKb-l`KO
Dateadd(mm,datediff(mm,0,getdate()),0) :(,uaX>{
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ny17(Y =
Dateadd(yy,datediff(yy,0,getdate()),0) +_uT1Ps BY
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) K2<Q9 ,vt
上面的SQL代码只是一个时间段 aG QC
Dateadd(wk,datediff(wk,0,getdate()),-1) :0ZFbIy
Dateadd(wk,datediff(wk,0,getdate()),6) uArs[e|f
就是表示本周时间段. xn(lkQ6Fm
下面的SQL的条件部分,就是查询时间段在本周范围内的: >=c<6#:s<9
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) g*Nc+W](P>
而在存储过程中 9RwD_`D(MN
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) aS?A3h4WM_
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) #/t^?$8\\