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。 Koi-b
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一、基础 O$(#gB'B
1、说明:创建数据库
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CREATE DATABASE database-name M\D25=(
2、说明:删除数据库 x>GxyVE
drop database dbname le150;7
3、说明:备份sql server ^JY,K
--- 创建 备份数据的 device pmuT7*<19
USE master DmiZ"A
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' =`OnFdI
--- 开始 备份 Fql|0Fq
BACKUP DATABASE pubs TO testBack `9&~fWu
4、说明:创建新表 J,D^fVIw
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) QIC? `hk1
根据已有的表创建新表: fA"9eUu
A:create table tab_new like tab_old (使用旧表创建新表) ^u+#x2$Mg
B:create table tab_new as select col1,col2... from tab_old definition only pC/13|I
5、说明:删除新表 .!)i
drop table tabname il[waUfmD
6、说明:增加一个列 !-~sxa280r
Alter table tabname add column col type 1xDh[:6
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。 ly::?
7、说明:添加主键: Alter table tabname add primary key(col) 1'!%$D
说明:删除主键: Alter table tabname drop primary key(col) b#W(&b^q
8、说明:创建索引:create [unique] index idxname on tabname(col....)
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删除索引:drop index idxname (b"kN(
注:索引是不可更改的,想更改必须删除重新建。 =Bos>;dl
9、说明:创建视图:create view viewname as select statement 7{Zs"d{s
删除视图:drop view viewname !7n`-#)
10、说明:几个简单的基本的sql语句 6B!v;93U
选择:select * from table1 where 范围 &R,QJ4L
插入:insert into table1(field1,field2) values(value1,value2) 6$&%z Eh
删除:delete from table1 where 范围 -u^f;4|u
更新:update table1 set field1=value1 where 范围 Y-.aSc53
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! XaH;
排序:select * from table1 order by field1,field2 [desc] X@\ 9}*9
总数:select count as totalcount from table1 YM&i
求和:select sum(field1) as sumvalue from table1 rCd*'Qg
平均:select avg(field1) as avgvalue from table1 t[p/65L>8
最大:select max(field1) as maxvalue from table1 @;7Ht Z`
最小:select min(field1) as minvalue from table1 9R99,um$
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11、说明:几个高级查询运算词 "J{A}g[
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A: UNION 运算符 z,g\7F[
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。 ttY[\D&ZS
B: EXCEPT 运算符 &HtG&RvQf
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。 *YP:-
C: INTERSECT 运算符 8 Y))/]R
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。 |4!G@-2V:I
注:使用运算词的几个查询结果行必须是一致的。 Bej k^V~
12、说明:使用外连接 /Q2HN(Y
A、left outer join: V)c.AX5
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。 #F#M<d3-2
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 i>
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B:right outer join: 3/Dis)
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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。 F- {hXM
C:full outer join: D22A)0+_
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。 NEt_UcC
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二、提升
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1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) [sl"\3)
法一:select * into b from a where 1<>1 ^+}~"nvD
法二:select top 0 * into b from a 6o]j@o8V
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) _xGC0f (
insert into b(a, b, c) select d,e,f from b; +J3Y}A4W3X
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) ]RxWypA`
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 T/?C_i
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 3il/{bgM
4、说明:子查询(表名1:a 表名2:b) 0Om<+]).R
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) /0r6/ _5-.
5、说明:显示文章、提交人和最后回复时间 +8.1cDEH\
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b ~iJ@x;`
6、说明:外连接查询(表名1:a 表名2:b) #:=*n(GT
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ok{
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7、说明:在线视图查询(表名1:a ) ?~X^YxWsY
select * from (SELECT a,b,c FROM a) T where t.a > 1; f@ .s(i=z
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 =D
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select * from table1 where time between time1 and time2 &%4A3.qE
select a,b,c, from table1 where a not between 数值1 and 数值2 &R3#? 1,
9、说明:in 的使用方法 (^$SMuC
select * from table1 where a [not] in ('值1','值2','值4','值6') @@& ?,3
10、说明:两张关联表,删除主表中已经在副表中没有的信息 {-51rAyi
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) $AHdjQ[;6-
11、说明:四表联查问题: }CvhLjo
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... ~:N 1[
12、说明:日程安排提前五分钟提醒 \9 k3;zw
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 FO)`&s"&2
13、说明:一条sql 语句搞定数据库分页 wu3p2#-Z
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 wRJ`RKJ-T
14、说明:前10条记录 9'A^n~JHF
select top 10 * form table1 where 范围 [_HOD^
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) w
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select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) toel!+
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 R) J/z
(select a from tableA ) except (select a from tableB) except (select a from tableC) P9M. J^<
17、说明:随机取出10条数据 l@g%A#
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select top 10 * from tablename order by newid() C~"b-T
18、说明:随机选择记录 Jp(CBCG{F
select newid() MS& 'Nj
19、说明:删除重复记录 Asli<L(?`
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) }^azj>p5
20、说明:列出数据库里所有的表名 1SG^X-(GM/
select name from sysobjects where type='U' :`Xg0J+P
21、说明:列出表里的所有的 ~T9wx
select name from syscolumns where id=object_id('TableName') 4S*dNYc
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 "]B%V!@
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type Jm-bE 8b
显示结果: Hu"TEhW(2
type vender pcs uE'Kk8
电脑 A 1 RP%FMb}nt
电脑 A 1 LUEZqIf
光盘 B 2 [{6fyd;
光盘 A 2 vOU9[n
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手机 B 3 :_pn|
手机 C 3 Q@/Z~xw"'I
23、说明:初始化表table1 8>[o.xV
TRUNCATE TABLE table1 >n jX=r.
24、说明:选择从10到15的记录 %VS+?4ww
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc "B0I$`~wu
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三、技巧 U3|9a8^H
1、1=1,1=2的使用,在SQL语句组合时用的较多 ^<Zye>KO
"where 1=1" 是表示选择全部 "where 1=2"全部不选, $t.M`:G
如: Zo@
if @strWhere !='' N]&:xd5
begin `{xKU8j^
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere j>Cp4
end NZZc[P
else !mK}Rim~
begin y0,>_MS
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' MbXtmQ%C8
end `(
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我们可以直接写成 `W2
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere xo#K_"E
2、收缩数据库 B[fbP rM
--重建索引 )^m"fQ+
DBCC REINDEX R+tQvxp#
DBCC INDEXDEFRAG Rl n% Y
--收缩数据和日志 eDsc_5I
DBCC SHRINKDB 0+Q;a
DBCC SHRINKFILE URj2 evYW
3、压缩数据库 abg`:E
dbcc shrinkdatabase(dbname) *@g>~q{`
4、转移数据库给新用户以已存在用户权限 Gq{ );fq
exec sp_change_users_login 'update_one','newname','oldname' r\$`e7d}!
go
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5、检查备份集 ~r&+18Z;
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 7-d.eNQl
6、修复数据库 H.&"~eH
ALTER DATABASE [dvbbs] SET SINGLE_USER 6)_h'v<|M
GO NB3ar&.$S
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK W('V2Z-q
GO #^xj"}o@
ALTER DATABASE [dvbbs] SET MULTI_USER ~$m:j];
GO l{hO"fzy
7、日志清除 ^IO\J{U{"x
SET NOCOUNT ON EC7)M}H
DECLARE @LogicalFileName sysname, kn}bb*eZ
@MaxMinutes INT, f s2}a
@NewSize INT NV`=T?1[5
USE tablename -- 要操作的数据库名 r>J%Eu/O
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 d?)Ic1][
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ;!)gjiapw
@NewSize = 1 -- 你想设定的日志文件的大小(M) G| qsJ
-- Setup / initialize BB.120v&N
DECLARE @OriginalSize int 'k/:3?R
SELECT @OriginalSize = size [I78<IJc
FROM sysfiles $.3J1DU
WHERE name = @LogicalFileName x57O.WdN
SELECT 'Original Size of ' + db_name() + ' LOG is ' + S+GW}?!
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + /hAy1V6
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 3 V$
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FROM sysfiles ,e;_
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WHERE name = @LogicalFileName afd.v$63
CREATE TABLE DummyTrans synueg
(DummyColumn char (8000) not null) QI`&N(n
DECLARE @Counter INT, j9&x#U
@StartTime DATETIME, u^( s0q
@TruncLog VARCHAR(255) WP
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SELECT @StartTime = GETDATE(), Bs^p!4=
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ICzcV };$
DBCC SHRINKFILE (@LogicalFileName, @NewSize) UVgDm&FF
EXEC (@TruncLog) S0?e/VWy
-- Wrap the log if necessary. \ \g Aa-}:
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired -d^c!Iu|
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) p$a+?5'Q
AND (@OriginalSize * 8 /1024) > @NewSize >f(M5v(D\
BEGIN -- Outer loop. q>[}JtXK
SELECT @Counter = 0 (Ji=fh+
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) SyIi*dH
BEGIN -- update Nh1,
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INSERT DummyTrans VALUES ('Fill Log') _^`TG]F
DELETE DummyTrans %!]CP1S
SELECT @Counter = @Counter + 1 n,Q^M$mS0
END O}X@QG2_
EXEC (@TruncLog) cpM]APF-
END aMaqlqf
SELECT 'Final Size of ' + db_name() + ' LOG is ' + U3t)yr h
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + SbH} cu8
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' h`4!Qv
FROM sysfiles \omfWWpK
WHERE name = @LogicalFileName UD^=@?^7
DROP TABLE DummyTrans @*iT%p_L
SET NOCOUNT OFF [#+klP$
8、说明:更改某个表 =H?^G[ y
exec sp_changeobjectowner 'tablename','dbo' rmPJid[8B~
9、存储更改全部表 Wt!8.d}=
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch "B*UZ.cC
@OldOwner as NVARCHAR(128), -*W\$P
@NewOwner as NVARCHAR(128) '3
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AS @^nE^;
DECLARE @Name as NVARCHAR(128) dm"|\7
DECLARE @Owner as NVARCHAR(128) L 7l"*w(
DECLARE @OwnerName as NVARCHAR(128) D{^CJ :n
DECLARE curObject CURSOR FOR N\85fPSMG|
select 'Name' = name, )5w# n1
'Owner' = user_name(uid) kcE86Y=|x!
from sysobjects +q] kpkG!
where user_name(uid)=@OldOwner U|v@v@IBA
order by name +5H1n(6)
OPEN curObject "O8iO!:
FETCH NEXT FROM curObject INTO @Name, @Owner 9XX:_9|I
WHILE(@@FETCH_STATUS=0) '3TfW61]
BEGIN 51`*VR]`K
if @Owner=@OldOwner M7//*Q'?
begin p?sFX$S
set @OwnerName = @OldOwner + '.' + rtrim(@Name) bRI `ZT0
exec sp_changeobjectowner @OwnerName, @NewOwner q1Ehl
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end nk2H^RM^
-- select @name,@NewOwner,@OldOwner q5~"8]Dls
FETCH NEXT FROM curObject INTO @Name, @Owner :xC1Ka%~
END *OHaqe(*
close curObject 6nW]Q^N}
deallocate curObject h&x;#.SYK
GO +d=8 /3O%
10、SQL SERVER中直接循环写入数据 8jz7t:0
declare @i int (*Q8!"D^6
set @i=1 +7j7zpw
while @i<30 oFp4*<\
begin AhQsv.t
insert into test (userid) values(@i) v[<;z(7Qk
set @i=@i+1 E<77Tj
end ^-%O
小记存储过程中经常用到的本周,本月,本年函数 N9=?IFEe]
Dateadd(wk,datediff(wk,0,getdate()),-1) #Wely~
Dateadd(wk,datediff(wk,0,getdate()),6) <+AvbqDe
Dateadd(mm,datediff(mm,0,getdate()),0) 1j+RXb\<
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) c='uyx
Dateadd(yy,datediff(yy,0,getdate()),0) -x+K#T0Z
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 1!A'mkk8
上面的SQL代码只是一个时间段 !0Eo9bU%@
Dateadd(wk,datediff(wk,0,getdate()),-1) Ev,b5KelD
Dateadd(wk,datediff(wk,0,getdate()),6) 'J_6SD
就是表示本周时间段. CB>*(Mu
下面的SQL的条件部分,就是查询时间段在本周范围内的: AV;x'H7G
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 8WLBq-]G
而在存储过程中 c<5(c%a
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) O{wt0 \P
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 'h `)6{