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。 7,&]1+n
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一、基础 I}g|n0o
1、说明:创建数据库 45O6TqepN
CREATE DATABASE database-name ^&G O4u
2、说明:删除数据库 x"C93ft[
drop database dbname ]a%\Q2[c
3、说明:备份sql server CDTk
--- 创建 备份数据的 device zm)CfEF
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USE master ^) b7m
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' WE Svkm;
--- 开始 备份 ]K0,nj*\c
BACKUP DATABASE pubs TO testBack -)->Jx:{
4、说明:创建新表 pS|JDMo
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) t&Y^W <
根据已有的表创建新表: V@+<,tjq
A:create table tab_new like tab_old (使用旧表创建新表) dv4r\ R^
B:create table tab_new as select col1,col2... from tab_old definition only (m =u;L"o
5、说明:删除新表 ow>[#.ua
drop table tabname tB(X`A.|
6、说明:增加一个列 pQgOT0f
Alter table tabname add column col type 4S{l>/I
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。 ['N#aDh.?
7、说明:添加主键: Alter table tabname add primary key(col) UXdC<(vK
说明:删除主键: Alter table tabname drop primary key(col) *!7SM7
8、说明:创建索引:create [unique] index idxname on tabname(col....) '$L= sH5
删除索引:drop index idxname <&m
注:索引是不可更改的,想更改必须删除重新建。 3Ns:O2|
9、说明:创建视图:create view viewname as select statement 2QuypVC ]
删除视图:drop view viewname u!EulAl
10、说明:几个简单的基本的sql语句 )mo|.L0
选择:select * from table1 where 范围 $GfxMt
插入:insert into table1(field1,field2) values(value1,value2) B& f~.UH
删除:delete from table1 where 范围 a~N)qYL:
更新:update table1 set field1=value1 where 范围 }"; hz*a
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! *.;}OX^X
排序:select * from table1 order by field1,field2 [desc] C`1\$U~%
总数:select count as totalcount from table1 5bqYi
求和:select sum(field1) as sumvalue from table1 :-'ri Ry
平均:select avg(field1) as avgvalue from table1 LM`tNZ1Fc!
最大:select max(field1) as maxvalue from table1 cF<DUr)Ve
最小:select min(field1) as minvalue from table1 }y=n#%|i.
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11、说明:几个高级查询运算词 zZ"')+7q&%
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A: UNION 运算符 v_F?x!
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 {~p %\
B: EXCEPT 运算符 x?k |i}Q
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 bA9dbe
C: INTERSECT 运算符 c$Nl-?W
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。 8w@jUGsc
注:使用运算词的几个查询结果行必须是一致的。 B(vz$QE,$r
12、说明:使用外连接 %$-3fj7
A、left outer join: HvfTC<+H
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。 F9G$$%Q-Z
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 [~r$US
B:right outer join: nv|y@!(
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。 6nk|*HPz
C:full outer join: JC?V].) y5
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。 W;x LuKIG
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二、提升 ).#D:eO[~
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) %;XuA*e
法一:select * into b from a where 1<>1 $,@+Ua
法二:select top 0 * into b from a n#AH@`&i
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) Vh-h{
insert into b(a, b, c) select d,e,f from b; )t 7HioQ
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) (YH{%8
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insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 #2t\>7]
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. R$'nWzX#
4、说明:子查询(表名1:a 表名2:b) sBG(CpQ
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) v?' k)B
5、说明:显示文章、提交人和最后回复时间 |8?{JKsg
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b u6&Ixi/s'
6、说明:外连接查询(表名1:a 表名2:b) j:<T<8.o
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c sU3V)7"
7、说明:在线视图查询(表名1:a ) w0>)y-
select * from (SELECT a,b,c FROM a) T where t.a > 1; [~H`9Ab=
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 3mn-dKe((
select * from table1 where time between time1 and time2 )$.9WlQ
select a,b,c, from table1 where a not between 数值1 and 数值2 Y7I
9、说明:in 的使用方法 :z5Ibas:
select * from table1 where a [not] in ('值1','值2','值4','值6') ,UJPLj^
10、说明:两张关联表,删除主表中已经在副表中没有的信息 *>H'@gS
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) KD<`-b)7<
11、说明:四表联查问题: 6*oTT(0<p
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... #z5?Y2t7~^
12、说明:日程安排提前五分钟提醒 TgG)btQ
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 uPD_s[
13、说明:一条sql 语句搞定数据库分页 yq^$H^_O
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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 RR {9
14、说明:前10条记录 [9Hm][|Ph
select top 10 * form table1 where 范围 fC:\Gh5
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.) xo3)dsX
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) X7!A(q+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 *VAi!3Rx;
(select a from tableA ) except (select a from tableB) except (select a from tableC) i;
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17、说明:随机取出10条数据 ;Awzm )Q
select top 10 * from tablename order by newid() zT 40,rk
18、说明:随机选择记录 \}(-9dr
select newid() JugQ +0
19、说明:删除重复记录 F#9KMu<<cI
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) 4p g(QeR
20、说明:列出数据库里所有的表名 s0'U[]
select name from sysobjects where type='U' wY)GX
21、说明:列出表里的所有的 jh!IOtf
select name from syscolumns where id=object_id('TableName') -2XIF}.Hu
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。 ,$*klod
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 o{,(`o.1O
显示结果: E 4(muhY
type vender pcs a.ME{:a%
电脑 A 1 667tL(
电脑 A 1 g)Uh
光盘 B 2 hRiGW_t
光盘 A 2 +PD5pr
手机 B 3 XX;%:?n
手机 C 3 rV{e[fGd
23、说明:初始化表table1 N1+]3kt ~
TRUNCATE TABLE table1 g9`ytWmM
24、说明:选择从10到15的记录 unB "dE
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 4}b:..Ku
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三、技巧 p_N=V. w
1、1=1,1=2的使用,在SQL语句组合时用的较多 z#!Cg*K(
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 5rhdm?Ls0
如: hYx^D>}]
if @strWhere !='' /qY(uPJ
begin ~~
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere l0,O4k2 '
end nP
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else "@Fxfd+Ot
begin vdM\scO:
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' uSbg*OA
end }gt~{9?c
我们可以直接写成 ,4UJ|D=J
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere @T T[H*,
2、收缩数据库 jV8><5C
--重建索引 iSax-Mc
DBCC REINDEX 6<GWDO
DBCC INDEXDEFRAG a_x6 v*
--收缩数据和日志 O`| ri5d
DBCC SHRINKDB s!\L1E
DBCC SHRINKFILE m]vr|:{6/
3、压缩数据库 Sy~Mh]{E
dbcc shrinkdatabase(dbname) %?y`_~G
4、转移数据库给新用户以已存在用户权限 {hR23eE)#
exec sp_change_users_login 'update_one','newname','oldname' c}cboe2
go /267Q;d
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5、检查备份集 Melc-[
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' suSIz 7:
6、修复数据库 vUNE!j
ALTER DATABASE [dvbbs] SET SINGLE_USER lDXH<W?
GO %;gWl1&5
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK G
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GO q5Mif\
ALTER DATABASE [dvbbs] SET MULTI_USER }9dgm[C[b
GO DKH9O
7、日志清除 &0TheY;srf
SET NOCOUNT ON K!mgh7Dx
DECLARE @LogicalFileName sysname, Hs` '](
@MaxMinutes INT, HBu>BSv:
@NewSize INT :-8u*5QK]`
USE tablename -- 要操作的数据库名 mUw,q;{
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 iE5^Xik,
@MaxMinutes = 10, -- Limit on time allowed to wrap log. `VbG%y&I
@NewSize = 1 -- 你想设定的日志文件的大小(M) XDQ1gg`
-- Setup / initialize YKk%;U*
DECLARE @OriginalSize int t~M_NEPxV
SELECT @OriginalSize = size $P~ a
FROM sysfiles :'=C/AL
WHERE name = @LogicalFileName i=UJ*c
SELECT 'Original Size of ' + db_name() + ' LOG is ' + )}v2Z3:
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + + u+fEg/A
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' x(~l[hT
FROM sysfiles bHNaaif}P
WHERE name = @LogicalFileName [8n4lE[)"
CREATE TABLE DummyTrans wz=I+IN:
(DummyColumn char (8000) not null) Gz:a1-x
DECLARE @Counter INT, h:wD
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@StartTime DATETIME, [%y D,8
@TruncLog VARCHAR(255) M`F L&Ac
SELECT @StartTime = GETDATE(), G Kr
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@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 8Sa<I.l
DBCC SHRINKFILE (@LogicalFileName, @NewSize) }"v"^5
EXEC (@TruncLog) >XN&QVE
-- Wrap the log if necessary. J)_42Z
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired $Re
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AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ;'urt /
AND (@OriginalSize * 8 /1024) > @NewSize ljRR
BEGIN -- Outer loop. sj~'.Zs%
SELECT @Counter = 0 1+Oo Qs
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) b7/4~_s
BEGIN -- update ZhU2z*qN#
INSERT DummyTrans VALUES ('Fill Log') (A_9;uL^_
DELETE DummyTrans >E# 4mm
SELECT @Counter = @Counter + 1 k,J?L-F
END 4{&
EXEC (@TruncLog) Qpc>5p![3
END D]REZuHOI
SELECT 'Final Size of ' + db_name() + ' LOG is ' + t s&C0
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + Y`v&YcX;
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' %!RQ:?=
FROM sysfiles n@f@-d$m\<
WHERE name = @LogicalFileName RY&~{yl$"1
DROP TABLE DummyTrans _'Z@ < ,L
SET NOCOUNT OFF f32nO
8、说明:更改某个表 <ZLs+|1
exec sp_changeobjectowner 'tablename','dbo' FqySnr JQ
9、存储更改全部表 $=
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CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch nBd;d}LD
@OldOwner as NVARCHAR(128), <\u%ZB
@NewOwner as NVARCHAR(128) #+$z`C`
AS vnE,}(M
DECLARE @Name as NVARCHAR(128) 9ZwhCsO
DECLARE @Owner as NVARCHAR(128) H4U;~)i
DECLARE @OwnerName as NVARCHAR(128) rHznXME$wZ
DECLARE curObject CURSOR FOR /C"E*a
select 'Name' = name, a"EXR-+8
'Owner' = user_name(uid) MWB?V?qPSC
from sysobjects {v(3[7
where user_name(uid)=@OldOwner %rkUy?=vu
order by name gyIPG2d
OPEN curObject F -m1GG0s
FETCH NEXT FROM curObject INTO @Name, @Owner pdM|dGq^
WHILE(@@FETCH_STATUS=0) |"arVde
BEGIN (Xx
@_
if @Owner=@OldOwner zT@vji%Y
begin mYZH]oo
set @OwnerName = @OldOwner + '.' + rtrim(@Name) D*b>
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exec sp_changeobjectowner @OwnerName, @NewOwner xJ4T7 )*
end iVA_a8}
-- select @name,@NewOwner,@OldOwner Wjp<(aY[
FETCH NEXT FROM curObject INTO @Name, @Owner {az8*MR=X
END ~dv
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close curObject 5}f$O
deallocate curObject 1K!7FiqY
GO .d;/6HD[y
10、SQL SERVER中直接循环写入数据 kC)dia{$
declare @i int Xo
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set @i=1 lw7wvZD
while @i<30 3=z'Ih`
begin No I=t
insert into test (userid) values(@i) jd#{66:
set @i=@i+1 x\lua
end &"=inkh
小记存储过程中经常用到的本周,本月,本年函数 y<Z8+/f`f
Dateadd(wk,datediff(wk,0,getdate()),-1) 6d,"GT
Dateadd(wk,datediff(wk,0,getdate()),6) f?)qZPM
Dateadd(mm,datediff(mm,0,getdate()),0) H&I0\upd
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) /IgTmXxxj
Dateadd(yy,datediff(yy,0,getdate()),0) %"o4IYV#
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 8<xJmcTEwO
上面的SQL代码只是一个时间段 3+IS7ATn
Dateadd(wk,datediff(wk,0,getdate()),-1) c#_%|gg
Dateadd(wk,datediff(wk,0,getdate()),6) $OmtN"
就是表示本周时间段. p[cC%3
下面的SQL的条件部分,就是查询时间段在本周范围内的: fZgZ
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) Te;`-EL
而在存储过程中 p!=/a)4X
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) u4%-e)$X
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) -)w/nq