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"F=tT7WP
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一、基础 Z?@oe-mz
1、说明:创建数据库 :gwM$2vv
CREATE DATABASE database-name VKZZTFmV2)
2、说明:删除数据库 vq?aFX9F
drop database dbname P5$L(x%~
3、说明:备份sql server b23 5Zm
--- 创建 备份数据的 device REK(^1
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USE master 5LYzX+a)
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' OV.f+_LS
--- 开始 备份 ;ZasK0
BACKUP DATABASE pubs TO testBack y;$
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4、说明:创建新表 MkNPC
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) >>>&{>}!
根据已有的表创建新表: bF"1M#u:
A:create table tab_new like tab_old (使用旧表创建新表) &"R`:`XF
B:create table tab_new as select col1,col2... from tab_old definition only N4L#$\M
5、说明:删除新表 UN8]>#\"`
drop table tabname GW;\3@o
6、说明:增加一个列 $XZC8L#
Alter table tabname add column col type NUQ?QQ
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。 79yF {
7、说明:添加主键: Alter table tabname add primary key(col) '0jjoZ:
说明:删除主键: Alter table tabname drop primary key(col) Cih~cwE
8、说明:创建索引:create [unique] index idxname on tabname(col....) ge[hAI2I
删除索引:drop index idxname 9f|+LN##
注:索引是不可更改的,想更改必须删除重新建。 F<YXkG4pO
9、说明:创建视图:create view viewname as select statement || }'
删除视图:drop view viewname rFJPeK7
10、说明:几个简单的基本的sql语句 DI)!x {"
选择:select * from table1 where 范围 t
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插入:insert into table1(field1,field2) values(value1,value2) X<8
删除:delete from table1 where 范围 O8mmS!
更新:update table1 set field1=value1 where 范围 O]1aez[
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! -Uj3?W
排序:select * from table1 order by field1,field2 [desc] ) 8_x
总数:select count as totalcount from table1 Q)s`~G({P
求和:select sum(field1) as sumvalue from table1 BYKONZu
平均:select avg(field1) as avgvalue from table1 JNx;/6'd,
最大:select max(field1) as maxvalue from table1 3~ptD5@WF
最小:select min(field1) as minvalue from table1 nf2[hx@=U
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11、说明:几个高级查询运算词 \Ctl(uj
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A: UNION 运算符 -ld1o+'`v!
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。 JNL9t0x
B: EXCEPT 运算符 4~DW7(
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。 H[e=^JuD
C: INTERSECT 运算符 `^G?+p2E
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。 >OotgJnhC
注:使用运算词的几个查询结果行必须是一致的。 Z'cL"n\9R]
12、说明:使用外连接 K1oSoD8c
A、left outer join: Qw@_.I
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。 u|Tg*B
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 ZR*Dl.GWY
B:right outer join: j96\({;k
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。 ,?KN;~t#vz
C:full outer join: sVNM#,
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。 I$Ra*r
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二、提升 _9B ^@~
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) JO =kfWW
法一:select * into b from a where 1<>1 $%"?0S
法二:select top 0 * into b from a 2t3DQ
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ( kFg2kG
insert into b(a, b, c) select d,e,f from b; {+N7o7
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) WW[G ne
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 "74Rn"d5
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 3o.9}`/
4、说明:子查询(表名1:a 表名2:b) i[N=.
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) 0<$t9:dq
5、说明:显示文章、提交人和最后回复时间 nf,u'}psdJ
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b ~}@cSv'(1
6、说明:外连接查询(表名1:a 表名2:b) ^)i1b:4
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c SMMvRF`7
7、说明:在线视图查询(表名1:a ) DRy,n)U&
select * from (SELECT a,b,c FROM a) T where t.a > 1; jT $
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 e:T8={LU2W
select * from table1 where time between time1 and time2 CGCI3Z'
select a,b,c, from table1 where a not between 数值1 and 数值2 Gi7p`F.
9、说明:in 的使用方法 LO@='}D=
select * from table1 where a [not] in ('值1','值2','值4','值6') CS\T@)@t
10、说明:两张关联表,删除主表中已经在副表中没有的信息 ^,sKj-
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) '(-SuaH49
11、说明:四表联查问题: )W0z
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 ..... w\{oOlE
12、说明:日程安排提前五分钟提醒 56l1&hp8In
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 NzAMX+L
13、说明:一条sql 语句搞定数据库分页 [[A}MF*@
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 ^E}};CsT
14、说明:前10条记录
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select top 10 * form table1 where 范围 ;cfmMt!QWJ
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.) eW/sPQ-
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) n/vKxtW
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 6U?z
(select a from tableA ) except (select a from tableB) except (select a from tableC) grbUR)f<?-
17、说明:随机取出10条数据 ?_BK(kL_
select top 10 * from tablename order by newid() yRtxh_wr9
18、说明:随机选择记录
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select newid() :@c\a99Kx
19、说明:删除重复记录 *L+)R*|:&
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) $PbwC6>8
20、说明:列出数据库里所有的表名 KOYcT'J@vR
select name from sysobjects where type='U' Nt/#Qu2#br
21、说明:列出表里的所有的 kW.it5Z#
select name from syscolumns where id=object_id('TableName')
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22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 4PDxmH]y
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type -j"]1JLQ
显示结果: r{
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type vender pcs %DIZgPd\
电脑 A 1 [W,} &
电脑 A 1 pdEUDuX
光盘 B 2 "+k^8ki
光盘 A 2 wzNGL{3
手机 B 3 IWs)n1D*]
手机 C 3 ;Q8LA",5d
23、说明:初始化表table1 FNgC TO%
TRUNCATE TABLE table1 ,5J}Wo?Q}
24、说明:选择从10到15的记录 se]q~<&
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc y{O817 \
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三、技巧 )a0%62
1、1=1,1=2的使用,在SQL语句组合时用的较多 ;($" _h
"where 1=1" 是表示选择全部 "where 1=2"全部不选, /^^wHW:
如: R8n/QCeY{
if @strWhere !='' 0fP-[7P
begin 60Szn]z'8[
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere j _p|>f<}
end 2PVtyV3;
else &vHfuM`
begin e0cVg
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' T(4OPiKu
end A2{s?L,
我们可以直接写成 [)KLmL%
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere u~\I
2、收缩数据库 s$PPJJT{b
--重建索引 XPd@>2
DBCC REINDEX WB(Gx_o3
DBCC INDEXDEFRAG \95O
--收缩数据和日志 Qs1e0LwA9
DBCC SHRINKDB lq*{2M{[
DBCC SHRINKFILE EI!e0V1!
3、压缩数据库 de$0D fK
dbcc shrinkdatabase(dbname) jc-$l
4、转移数据库给新用户以已存在用户权限 8AQ@?\Rc"2
exec sp_change_users_login 'update_one','newname','oldname' vAH `tPi>
go KDEcR
5、检查备份集 =*Ru2
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' H%^j yGS
6、修复数据库 c$AwJhl^]
ALTER DATABASE [dvbbs] SET SINGLE_USER Jh!'"7
GO pon0!\ZT=
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK wr{ [4$O
GO K! e51P
ALTER DATABASE [dvbbs] SET MULTI_USER ,'c?^ $J|z
GO iciw 54;4
7、日志清除 %FSY}65
SET NOCOUNT ON lJ$j[Y
DECLARE @LogicalFileName sysname, 1C]mxV=%
@MaxMinutes INT, 4o``t]
@NewSize INT DF`?D
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USE tablename -- 要操作的数据库名 |
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SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 #[ZNiaWT
@MaxMinutes = 10, -- Limit on time allowed to wrap log. NpN-''B\
@NewSize = 1 -- 你想设定的日志文件的大小(M) >2[nTfS
-- Setup / initialize Vb$4'K'
DECLARE @OriginalSize int A[6D40o
SELECT @OriginalSize = size R!2oj_
FROM sysfiles =&YhA}l\O
WHERE name = @LogicalFileName .sE5QRVc
SELECT 'Original Size of ' + db_name() + ' LOG is ' + WO<a^g
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CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' +
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 71(C@/J
FROM sysfiles ?@LqrKj11
WHERE name = @LogicalFileName \2huDNW&
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CREATE TABLE DummyTrans X^c2
(DummyColumn char (8000) not null) (>usa||
DECLARE @Counter INT, ^j>w<ljzz
@StartTime DATETIME, TeXt'G=M
@TruncLog VARCHAR(255) /lqVMlz\77
SELECT @StartTime = GETDATE(), n,vs(ZL:
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ?X5Y8n]y\h
DBCC SHRINKFILE (@LogicalFileName, @NewSize) }=T=Z#OgH
EXEC (@TruncLog) `iT{H]po
-- Wrap the log if necessary. v[J"/:]
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Yv ZcG3@c3
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) C]'ru
AND (@OriginalSize * 8 /1024) > @NewSize I?Fv!5p
BEGIN -- Outer loop. yG..B
SELECT @Counter = 0 :,[=g$CT:
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) d]!`II
BEGIN -- update 5?M d
INSERT DummyTrans VALUES ('Fill Log') ^p}|""\j
DELETE DummyTrans SoPiEq
SELECT @Counter = @Counter + 1 N:nhS3N<L
END $7
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EXEC (@TruncLog) G>>TB{}
END &w7Ev21
SELECT 'Final Size of ' + db_name() + ' LOG is ' + m&!4*D
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + h
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CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ).D+/D/"2
FROM sysfiles 9f U,_`r
WHERE name = @LogicalFileName l Taw6;
DROP TABLE DummyTrans <]e 0TU?bk
SET NOCOUNT OFF 3d81]!n
8、说明:更改某个表 6xq/
exec sp_changeobjectowner 'tablename','dbo' jSc!"Trl]
9、存储更改全部表 bxR6@
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch BfOQ/k))
@OldOwner as NVARCHAR(128), PTZ/jg@71
@NewOwner as NVARCHAR(128) Z?"f#
AS M`u&-6
DECLARE @Name as NVARCHAR(128) op5G}QZ
DECLARE @Owner as NVARCHAR(128) Tc.k0n%W:b
DECLARE @OwnerName as NVARCHAR(128) BK;Gh0mp
DECLARE curObject CURSOR FOR {.mPe|
select 'Name' = name, i0/RvrLc
'Owner' = user_name(uid) Pua|Z
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from sysobjects {>rGe#Vu
where user_name(uid)=@OldOwner wR]jJbF
order by name ?CU6RC n
OPEN curObject Ww)p&don
FETCH NEXT FROM curObject INTO @Name, @Owner yDe6f(D
WHILE(@@FETCH_STATUS=0) r)xkpa5
BEGIN +$y%H
if @Owner=@OldOwner Tt\h#E
begin SSo7
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set @OwnerName = @OldOwner + '.' + rtrim(@Name)
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exec sp_changeobjectowner @OwnerName, @NewOwner Nt'6Y;m!
end ,C97|6rC
-- select @name,@NewOwner,@OldOwner Md[M}d8
FETCH NEXT FROM curObject INTO @Name, @Owner jqv"8S5
END MFzJ 8^.1R
close curObject 'h.:-1# L
deallocate curObject m(DJ6CSa
GO B3C%**~:e
10、SQL SERVER中直接循环写入数据 /;{E}`
declare @i int sDXD>upO
set @i=1 Svqj@@_f
while @i<30 bbe$6x wi
begin mi]bS
insert into test (userid) values(@i) :XFr"aSt
set @i=@i+1 jRGslak;
end XV %DhR=
小记存储过程中经常用到的本周,本月,本年函数 |9'`;4W
Dateadd(wk,datediff(wk,0,getdate()),-1) kfj)`x
Dateadd(wk,datediff(wk,0,getdate()),6) X"Ca
Dateadd(mm,datediff(mm,0,getdate()),0) dgp1 B\
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) 3[F9qDAy
Dateadd(yy,datediff(yy,0,getdate()),0) Q/zlU@
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) /9@[gv
A
上面的SQL代码只是一个时间段 {i#z<ttu
Dateadd(wk,datediff(wk,0,getdate()),-1) Wb{0UkApJ
Dateadd(wk,datediff(wk,0,getdate()),6) hb="J349
就是表示本周时间段. 19j"Zxdg Y
下面的SQL的条件部分,就是查询时间段在本周范围内的: -g\ ;B
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) )Gm,%[?2C
而在存储过程中 CR8szMa
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) eEl71
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) BL[N