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。 #g=7fu{n:
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一、基础 ~xCv_u^=
1、说明:创建数据库 iC2``[m"
CREATE DATABASE database-name -?z#
2、说明:删除数据库 )xm[m vt
drop database dbname {#y~ Qk;T
3、说明:备份sql server x18(}4
--- 创建 备份数据的 device XtCG.3(LY
USE master _xY
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EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' Vq$8!#~w
--- 开始 备份 mSeCXCrZlI
BACKUP DATABASE pubs TO testBack l]R=I2t
4、说明:创建新表 +adwEYRrr
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) FNlS)Bs
根据已有的表创建新表: '-X[T}
A:create table tab_new like tab_old (使用旧表创建新表) Q-<h)WTA
B:create table tab_new as select col1,col2... from tab_old definition only !:baG]Y
5、说明:删除新表 *{DpNV8"
drop table tabname duQ,6
6、说明:增加一个列 TAB'oLNp
Alter table tabname add column col type 1
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注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 0#Ae<
7、说明:添加主键: Alter table tabname add primary key(col) 717S3knlv
说明:删除主键: Alter table tabname drop primary key(col) O#MaZ.=
8、说明:创建索引:create [unique] index idxname on tabname(col....) N1iP!m9Q
删除索引:drop index idxname )5Wt(p:T6_
注:索引是不可更改的,想更改必须删除重新建。 &$yxAqdab
9、说明:创建视图:create view viewname as select statement +9exap27
删除视图:drop view viewname /#}o19(-d
10、说明:几个简单的基本的sql语句 ;x.5_Xw{.
选择:select * from table1 where 范围 3FY87R
插入:insert into table1(field1,field2) values(value1,value2) j[CXIz?c
删除:delete from table1 where 范围 <c3Te$.
更新:update table1 set field1=value1 where 范围 oZ5 ,y+L4
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! L9{y1'')
排序:select * from table1 order by field1,field2 [desc] Y[!s:3\f
总数:select count as totalcount from table1 CFXr=.yz
求和:select sum(field1) as sumvalue from table1 B@k2lHks(
平均:select avg(field1) as avgvalue from table1 56o(gCj?y
最大:select max(field1) as maxvalue from table1 Q2qT[aD,
最小:select min(field1) as minvalue from table1 *Za'^ Z2
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11、说明:几个高级查询运算词 ULH<FDot
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A: UNION 运算符 O@HL%ha
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 r17"i.n
B: EXCEPT 运算符 gz#2}
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。
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C: INTERSECT 运算符 +I3j2u8L
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 i0nu5kD+d
注:使用运算词的几个查询结果行必须是一致的。 ?t)Mt]("
12、说明:使用外连接 a(IUAh*mO
A、left outer join: XM f>B|
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 LEuDDJ-
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c x3:d/>b
B:right outer join: ZiW&*nN?M
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 i^@hn>s$
C:full outer join: |@5G\N -
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。 `*WzHDv5p
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二、提升 .cm9&&"Z
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) o-<XR9,N*
法一:select * into b from a where 1<>1 &$bcB]C\3
法二:select top 0 * into b from a '>cZ7:
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 068DC_
insert into b(a, b, c) select d,e,f from b; :.=#U
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) XTJA"y
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 "m>BE
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 4Ss*h,Y
4、说明:子查询(表名1:a 表名2:b) `m}G{ jfk
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) Y0yu,
5、说明:显示文章、提交人和最后回复时间 ~p?D[]h
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 3 S .2
6、说明:外连接查询(表名1:a 表名2:b) @ 3rJ $6W
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 3"Zc|Ck <?
7、说明:在线视图查询(表名1:a ) O"}O~lZ[6T
select * from (SELECT a,b,c FROM a) T where t.a > 1; +w?-#M#
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 !t[;~`d9
select * from table1 where time between time1 and time2 qND:LP\_v
select a,b,c, from table1 where a not between 数值1 and 数值2 SohNk9u[8
9、说明:in 的使用方法 E|3[$?=R
select * from table1 where a [not] in ('值1','值2','值4','值6') / hg)=p
10、说明:两张关联表,删除主表中已经在副表中没有的信息 r{{5@
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) @6M>x=n5
11、说明:四表联查问题: [9d\WPLC
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 ..... ;OC{B}.vH
12、说明:日程安排提前五分钟提醒 WMS~Bk+!
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 %GP`H/H(
13、说明:一条sql 语句搞定数据库分页 q'9;
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 YJ+l
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14、说明:前10条记录 7+Er}y>
select top 10 * form table1 where 范围 F. I\?b
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.) EMPujik-
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 9"?;H%.
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 ~l('ly
(select a from tableA ) except (select a from tableB) except (select a from tableC) ~7gFddi=i
17、说明:随机取出10条数据 X4L@|"ZI
select top 10 * from tablename order by newid() \0K&2'
18、说明:随机选择记录 M< H+$}[
select newid() 'U,\5jj'Y
19、说明:删除重复记录 \!"3yd
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) Wo Z@
20、说明:列出数据库里所有的表名 5S[:;o
select name from sysobjects where type='U' x\IuM
21、说明:列出表里的所有的 k*OHI/uiow
select name from syscolumns where id=object_id('TableName') >`^;h]Q
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 ?69E_E
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type ]@m`bs_6
显示结果: #\ECQF
type vender pcs 8_Z"@
电脑 A 1 2UopGxrPKw
电脑 A 1 =3nA5'UZ
光盘 B 2 vR
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光盘 A 2 vuZ'Wo:S{
手机 B 3 Kpkpr`:)]
手机 C 3 9VMk?
23、说明:初始化表table1 &;RBG$t
TRUNCATE TABLE table1 pd|l&xvka
24、说明:选择从10到15的记录 - _~\d+>w
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc /i
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三、技巧 :Dfl ,=S
1、1=1,1=2的使用,在SQL语句组合时用的较多 x_9#:_S'
"where 1=1" 是表示选择全部 "where 1=2"全部不选, lt yhYPS
如: s)Xz}QPK.
if @strWhere !='' ']d(m?
begin vsPIvW!V
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere S_ra8HY8
end 5~$WSL?O)
else HIUP
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begin zCv)%y
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' (1[Z#y[
end lR/Uboyy
我们可以直接写成 XtE O )
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere Ffd4c
2、收缩数据库 ~Lq`a@]A
--重建索引 YV'B*arIA
DBCC REINDEX Esm=sPW
DBCC INDEXDEFRAG %0({MU
--收缩数据和日志 q,OCA\
DBCC SHRINKDB *,)1Dcv(
DBCC SHRINKFILE {{)pb>E
3、压缩数据库 M,cz7,
dbcc shrinkdatabase(dbname) IR?nH`V
4、转移数据库给新用户以已存在用户权限 >QPCYo<E
exec sp_change_users_login 'update_one','newname','oldname' ]bbP_n8
go 3NdO3-~)
5、检查备份集 $oJjgA xcZ
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' #bCUI*N"P
6、修复数据库 =@&>r5W1
ALTER DATABASE [dvbbs] SET SINGLE_USER s@g _F
GO p} JGx^X~
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK o?+?@Xb'
GO DHbS=Iih
ALTER DATABASE [dvbbs] SET MULTI_USER n<F3&2w
GO ItVVI"-
7、日志清除 p<&>1}j=
SET NOCOUNT ON Y/LS(b*
DECLARE @LogicalFileName sysname, "Bz#5kqnl
@MaxMinutes INT, i~3\dp
@NewSize INT brK7|&R<
USE tablename -- 要操作的数据库名 b&]z^_m)
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 GnCs_[*&r
@MaxMinutes = 10, -- Limit on time allowed to wrap log. *^XMf
@NewSize = 1 -- 你想设定的日志文件的大小(M) e.Jaq^Gw|
-- Setup / initialize 1/syzHjbY
DECLARE @OriginalSize int wa!z:}]
SELECT @OriginalSize = size 9Z"WV5o
FROM sysfiles Ft}nG&D
WHERE name = @LogicalFileName ,zdK%V}
SELECT 'Original Size of ' + db_name() + ' LOG is ' + @:@5BCs<
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + CYsLyk
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' %s ;5
FROM sysfiles Fu% n8
WHERE name = @LogicalFileName >"z`))9
CREATE TABLE DummyTrans FE:}D;$
(DummyColumn char (8000) not null) ^W`RBrJay
DECLARE @Counter INT, x_ <,GE@
@StartTime DATETIME, 3JD"* <zs
@TruncLog VARCHAR(255) 9yu#G7
SELECT @StartTime = GETDATE(), 'j?H>'t{
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' Hn/V*RzQ
DBCC SHRINKFILE (@LogicalFileName, @NewSize) uc\G)BN
EXEC (@TruncLog) N/1xc1$SB
-- Wrap the log if necessary. jthyZZ
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired V2:S
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AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) I|2dV9y
AND (@OriginalSize * 8 /1024) > @NewSize
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BEGIN -- Outer loop. .bRtK+}F#
SELECT @Counter = 0 E 0OHl
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) jw/@]f;N
BEGIN -- update m63>P4h?
INSERT DummyTrans VALUES ('Fill Log') hpq\
DELETE DummyTrans Bsk` e
SELECT @Counter = @Counter + 1 h
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END oW>e.}d!
EXEC (@TruncLog) dnM.
END uH7!)LE#
SELECT 'Final Size of ' + db_name() + ' LOG is ' + Dc 84^>l
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + dKevhm)R"
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 5A%Uv*
FROM sysfiles ]vw%J ^7:a
WHERE name = @LogicalFileName p _2Y c]8
DROP TABLE DummyTrans 6KE64: \;
SET NOCOUNT OFF 7f*b5$+r
8、说明:更改某个表 )%
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exec sp_changeobjectowner 'tablename','dbo' :OqEkh"$#
9、存储更改全部表 1_8@yO
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch {$7vd
@OldOwner as NVARCHAR(128), .x}xa
@NewOwner as NVARCHAR(128) 1suP7o A;
AS Mp^G7JY,
DECLARE @Name as NVARCHAR(128) kX*.BZI}C
DECLARE @Owner as NVARCHAR(128) k9&W0$I#
DECLARE @OwnerName as NVARCHAR(128) Gs4t6+Al
DECLARE curObject CURSOR FOR i&<@}:,
select 'Name' = name, ]
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'Owner' = user_name(uid) ]4'V59\
from sysobjects q4vHsy36
where user_name(uid)=@OldOwner '$4&q629d
order by name OLGMy5
OPEN curObject @Y ?p-&
FETCH NEXT FROM curObject INTO @Name, @Owner 5kHU'D
WHILE(@@FETCH_STATUS=0) VkId6k:>6C
BEGIN M"Z/E>ne
if @Owner=@OldOwner g>a%
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begin _UbyhBl
set @OwnerName = @OldOwner + '.' + rtrim(@Name) @HY P_hR
exec sp_changeobjectowner @OwnerName, @NewOwner kkOjAp{<t
end ;g?o~ev 8
-- select @name,@NewOwner,@OldOwner x4`|[
FETCH NEXT FROM curObject INTO @Name, @Owner T:!H^
END sdKm@p|/|
close curObject [vnxp/v/<
deallocate curObject |-%dN }O
GO yb\!4ml
10、SQL SERVER中直接循环写入数据 ^a|
declare @i int :>jzL8
set @i=1 M(ie1Ju
while @i<30 n8q%>.i7
begin }{[p<pU$C
insert into test (userid) values(@i) ++!0r['+>
set @i=@i+1 sD6vHX%
end }kJ9<h,
小记存储过程中经常用到的本周,本月,本年函数 #9A*B bY
Dateadd(wk,datediff(wk,0,getdate()),-1) Qe]&
Dateadd(wk,datediff(wk,0,getdate()),6) Q.V+s
Dateadd(mm,datediff(mm,0,getdate()),0) q 1A0-W#4
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) "rrE_
Dateadd(yy,datediff(yy,0,getdate()),0) Re1}aLd
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 5X9*K
上面的SQL代码只是一个时间段 ?9~|K/ `l
Dateadd(wk,datediff(wk,0,getdate()),-1) #qEUGD`
Dateadd(wk,datediff(wk,0,getdate()),6) S@ItgG?X
就是表示本周时间段. TUQe.oAi
下面的SQL的条件部分,就是查询时间段在本周范围内的: jz I,B
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 1NAtg*`
而在存储过程中 `R-VJR 2"
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) c=Zurqj
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) m'2EiYX$}\