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。 j;
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一、基础 &g`a [#
1、说明:创建数据库 S;g~xo
CREATE DATABASE database-name s"/8h#!zv
2、说明:删除数据库 u=[oo@Rk`
drop database dbname f2=s{0SX0
3、说明:备份sql server WA/\x
--- 创建 备份数据的 device L{-w9(S`i
USE master |]Xw1.S.L
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' k#.co~kS
--- 开始 备份 }bVyvH
BACKUP DATABASE pubs TO testBack C*9m `xh
4、说明:创建新表 kLhtkuS4
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) _W+TZa@_
根据已有的表创建新表: #E1*1E
A:create table tab_new like tab_old (使用旧表创建新表) BzZy s
B:create table tab_new as select col1,col2... from tab_old definition only Fmu R(f=
5、说明:删除新表
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drop table tabname ~$$V=$&
6、说明:增加一个列 HUJ $e2[
Alter table tabname add column col type &}FYz8w 2/
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。 r0sd_@Oj
7、说明:添加主键: Alter table tabname add primary key(col) b6lL8KOu
说明:删除主键: Alter table tabname drop primary key(col) + y^s
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8、说明:创建索引:create [unique] index idxname on tabname(col....) `y\:3bQ4
删除索引:drop index idxname ,'j5tU?c
注:索引是不可更改的,想更改必须删除重新建。 }&j&T9oX
9、说明:创建视图:create view viewname as select statement ?aCR>AY5X
删除视图:drop view viewname 7 mN?;X33
10、说明:几个简单的基本的sql语句 Cur)|
选择:select * from table1 where 范围 -zkB`~u_
插入:insert into table1(field1,field2) values(value1,value2) QWoEo
删除:delete from table1 where 范围 1/m/Iw@
更新:update table1 set field1=value1 where 范围 gUMUh]j
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! V= _8G3
排序:select * from table1 order by field1,field2 [desc] $`
总数:select count as totalcount from table1 ,d7@*>T&
求和:select sum(field1) as sumvalue from table1 &ke4":7X
平均:select avg(field1) as avgvalue from table1 x.q%O1
最大:select max(field1) as maxvalue from table1 "*0
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最小:select min(field1) as minvalue from table1 li{_biey}
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11、说明:几个高级查询运算词 @dXf_2Tv=
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A: UNION 运算符 }vi%pfrB
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 2Zm*f2$xM
B: EXCEPT 运算符 /b*@dy
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。 BYY>;>V
C: INTERSECT 运算符 YPM>FDxDB
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。 yZ 9 *oDs
注:使用运算词的几个查询结果行必须是一致的。 1$|z%(
12、说明:使用外连接 MMf6QxYf
A、left outer join: JUE>g8\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。 \u*,~J)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 3w@)/ujn
B:right outer join: UJZa1p@L
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。 IP >An8+
C:full outer join: HDaec`j
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。 |\ay^@N
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二、提升 =_XcG!"
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) t.w?OyO
法一:select * into b from a where 1<>1 o{
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法二:select top 0 * into b from a 1eJ\CdI
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) LJ)3!Q/:
insert into b(a, b, c) select d,e,f from b; sq^,l6es>
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) KGJB.<Be
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 D|S)/o6
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. o ).pF">jh
4、说明:子查询(表名1:a 表名2:b) |gaZq!l
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) %cv%u6 b
5、说明:显示文章、提交人和最后回复时间 52~k:"c
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b jm?mO9p~
6、说明:外连接查询(表名1:a 表名2:b) T>z@;5C
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c C
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7、说明:在线视图查询(表名1:a ) 6nDx;x&Q
select * from (SELECT a,b,c FROM a) T where t.a > 1; qN) cB?+
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 &sRyM'XI
select * from table1 where time between time1 and time2 w\M_3}
select a,b,c, from table1 where a not between 数值1 and 数值2 h"'f~KM9a>
9、说明:in 的使用方法 <@yyx7
select * from table1 where a [not] in ('值1','值2','值4','值6') NUU}8a(K
10、说明:两张关联表,删除主表中已经在副表中没有的信息
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delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) .{}t[U
11、说明:四表联查问题: F7hQNQu:
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 ..... nYe}d!
12、说明:日程安排提前五分钟提醒 zb4g\H
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SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 V^ :\/EU
13、说明:一条sql 语句搞定数据库分页 p$V+IJtO(
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 ygPZkvZ
14、说明:前10条记录 iaC$K@a{
select top 10 * form table1 where 范围 p[wjHfIq
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) qvscf_%FM
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 1@ina`!1O
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 :JS}(
(select a from tableA ) except (select a from tableB) except (select a from tableC) NanU%#&
17、说明:随机取出10条数据 %Xi%LUk{
select top 10 * from tablename order by newid() 8 2qe|XD4p
18、说明:随机选择记录 =Dz[|$dV
select newid() -7`J(f.rYC
19、说明:删除重复记录 5Q88OxH
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) k8ck#%#}Wu
20、说明:列出数据库里所有的表名 %(]rc%ry0
select name from sysobjects where type='U' \Q$);:=qQ
21、说明:列出表里的所有的 +u#x[xO
select name from syscolumns where id=object_id('TableName') jyC6:BNust
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。 $_VD@YlAp
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type ieI-_]|[
显示结果: Hke\W'&
type vender pcs IlrmXSr
电脑 A 1 r:IU+3
电脑 A 1 N7_Co;#(zK
光盘 B 2 _H,RcpyJ
光盘 A 2 "f3>20}
手机 B 3 \,Ndg*qC
手机 C 3 c"xaN
23、说明:初始化表table1 }pA4#{)
TRUNCATE TABLE table1 {x:IsQZ
24、说明:选择从10到15的记录 9Dl \S F[
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc *v9G#[gG
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三、技巧 9V&LJhDQ
1、1=1,1=2的使用,在SQL语句组合时用的较多 m";gD[m
"where 1=1" 是表示选择全部 "where 1=2"全部不选, ?]z
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如: K"1J1>CHQ
if @strWhere !='' 5f5ZfK3<i
begin R4/@dA0
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ($s{em4L
end $W]bw#NH
else z-DpLV
begin DkIFvsLK
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' [xPE?OD
end | QA8"&r
我们可以直接写成 #vSI_rt9I
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere *v+ fkg
2、收缩数据库 >UMnItq(l
--重建索引 To`?<]8
DBCC REINDEX YO,ldsSz|r
DBCC INDEXDEFRAG O^#u%/
--收缩数据和日志 s<b7/;w'
DBCC SHRINKDB #7=LI\
DBCC SHRINKFILE =S,<yQJ
3、压缩数据库 gISs+g
dbcc shrinkdatabase(dbname) GLyh1qNX
4、转移数据库给新用户以已存在用户权限 @XmkIm
exec sp_change_users_login 'update_one','newname','oldname' jq)|Uq'6
go 9[D7N
5、检查备份集 $w\ , ."y
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' M6iKl
6、修复数据库 k:Q<Uanc[
ALTER DATABASE [dvbbs] SET SINGLE_USER AHGcWS\,X
GO N3p3"4_]fy
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK _=5ZB_I
GO S<~nk-xr*h
ALTER DATABASE [dvbbs] SET MULTI_USER k 9rnT)YU
GO Oe`t!&v
7、日志清除 ^~l<N@
SET NOCOUNT ON Ks(U]G"V
DECLARE @LogicalFileName sysname, LS'=>s"
@MaxMinutes INT, ?W_U{=anl
@NewSize INT JuSS5 _&
USE tablename -- 要操作的数据库名 =L%3q <]p
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 <h9\ A&
@MaxMinutes = 10, -- Limit on time allowed to wrap log. H%]ch6C
@NewSize = 1 -- 你想设定的日志文件的大小(M) kqw? X{
-- Setup / initialize [[Z>(d$8
DECLARE @OriginalSize int B:cOcd?p
SELECT @OriginalSize = size c ?XUb[
FROM sysfiles 'OCo1|iK~
WHERE name = @LogicalFileName xQap44KPZ
SELECT 'Original Size of ' + db_name() + ' LOG is ' + uszSFe]E
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + u,:`5*al{
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 6/ipdi[
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FROM sysfiles (B<AK4G
WHERE name = @LogicalFileName C&kl*nO
CREATE TABLE DummyTrans :'~ gLW>j
(DummyColumn char (8000) not null) &tCtCk%{j
DECLARE @Counter INT, X>7]g670@
@StartTime DATETIME, 0z7mre^Q
@TruncLog VARCHAR(255) ecpUp39\
SELECT @StartTime = GETDATE(), Ws)X5C=A
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ZGhoV#T@
DBCC SHRINKFILE (@LogicalFileName, @NewSize) +z0}{,HX
EXEC (@TruncLog) a<TL&
-- Wrap the log if necessary. +t4m\/y
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired **w~
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 92VX5?Cyg
AND (@OriginalSize * 8 /1024) > @NewSize #l# [\6
BEGIN -- Outer loop. NqE7[wH
SELECT @Counter = 0 wS*CcIwj
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) rq["O/2
BEGIN -- update h./vTNMc
INSERT DummyTrans VALUES ('Fill Log') kDY]>v
DELETE DummyTrans A>%UYA
SELECT @Counter = @Counter + 1 ,9wenr
END iCRw}[[
EXEC (@TruncLog) KGmc*Jwy
END g{)H"
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SELECT 'Final Size of ' + db_name() + ' LOG is ' +
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CONVERT(VARCHAR(30),size) + ' 8K pages or ' + =GKYroNM
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' XqS*;Zj0
FROM sysfiles np\2sa`
WHERE name = @LogicalFileName 8t:h
DROP TABLE DummyTrans ^@lg5d3F
SET NOCOUNT OFF >"g<-!p@
8、说明:更改某个表 ]!G>8Rc
exec sp_changeobjectowner 'tablename','dbo' 'ag6B(0Z
9、存储更改全部表 .4re0:V
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch GL =XiBt
@OldOwner as NVARCHAR(128), 9'#.>Q>0=j
@NewOwner as NVARCHAR(128) ro^6:w3O^
AS 6Y_O^f
DECLARE @Name as NVARCHAR(128) Xe3z6
DECLARE @Owner as NVARCHAR(128) DT"Zq
DECLARE @OwnerName as NVARCHAR(128) ->2wrOH|H
DECLARE curObject CURSOR FOR +<WRB\W
select 'Name' = name, P,;b'-5C
'Owner' = user_name(uid) JRjMt-7H_
from sysobjects 1;kG[z=A
where user_name(uid)=@OldOwner l&??2VO/t
order by name T19rbL_
OPEN curObject `TD%M`a
FETCH NEXT FROM curObject INTO @Name, @Owner Ik-E4pxKo
WHILE(@@FETCH_STATUS=0) 'Rkvsch
BEGIN *- IlF]
if @Owner=@OldOwner a}qse5Fr
begin |Iok(0V
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 56=K@$L {F
exec sp_changeobjectowner @OwnerName, @NewOwner iPY vePQ
end Fwx~ ~"I
-- select @name,@NewOwner,@OldOwner MpIw^a3(r
FETCH NEXT FROM curObject INTO @Name, @Owner ZA_zKJ[[7
END s 9|a2/{
close curObject ,;cel^.b
deallocate curObject bg1"v a#2
GO (O_t5<A*X
10、SQL SERVER中直接循环写入数据 j*H;a ?Y
declare @i int 4)odFq:
set @i=1 aFr!PQp4{
while @i<30 eC^0I78x
begin ~ACP%QM=
insert into test (userid) values(@i) A
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set @i=@i+1 I`"-$99|t1
end <nw<v9Z
小记存储过程中经常用到的本周,本月,本年函数 wj#J>C2]
Dateadd(wk,datediff(wk,0,getdate()),-1) E)80S.V
Dateadd(wk,datediff(wk,0,getdate()),6) %uz|NRB=
Dateadd(mm,datediff(mm,0,getdate()),0) $d2kHT
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) iz9\D*or
Dateadd(yy,datediff(yy,0,getdate()),0) Sqdc1zC
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) +24|_Lx0
上面的SQL代码只是一个时间段 Mm5U`mB
Dateadd(wk,datediff(wk,0,getdate()),-1) >
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Dateadd(wk,datediff(wk,0,getdate()),6) y|e2j&m
就是表示本周时间段. 4V228>9w
下面的SQL的条件部分,就是查询时间段在本周范围内的: JtYYT/PB
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) Wkg*J3O
而在存储过程中 'NT#(m%
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) pcRF:~TE
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) !@^y)v