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。 )' ,dP)b
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一、基础 @n9iOf~<
1、说明:创建数据库 ]d%Ou]609
CREATE DATABASE database-name ts@e
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2、说明:删除数据库 W$l4@A
drop database dbname Z$m&F0g
3、说明:备份sql server ?vF8 y;Jh
--- 创建 备份数据的 device 1GLb^:~A
USE master kDE:KV<"c
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' ,m7Z w_.
--- 开始 备份 9!2$?xqym
BACKUP DATABASE pubs TO testBack jE5=e</
4、说明:创建新表 nSZp,?^
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) Kuk@x.~0m
根据已有的表创建新表: yTe25l{QaF
A:create table tab_new like tab_old (使用旧表创建新表) LS#_K-
B:create table tab_new as select col1,col2... from tab_old definition only #L*MMC"
5、说明:删除新表 [5M! '
drop table tabname VzcW9'"#
6、说明:增加一个列 -%[6q
Alter table tabname add column col type :,/
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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。 xs"\c7pC
7、说明:添加主键: Alter table tabname add primary key(col) $SniQ
说明:删除主键: Alter table tabname drop primary key(col) @}+B%R
8、说明:创建索引:create [unique] index idxname on tabname(col....) -wNhbV2
删除索引:drop index idxname Spo[JQ%6
注:索引是不可更改的,想更改必须删除重新建。 CJ#Yu3}
9、说明:创建视图:create view viewname as select statement #0#6eT{-
删除视图:drop view viewname P;&U3i
10、说明:几个简单的基本的sql语句 NX]6RZr-
选择:select * from table1 where 范围 (15.?9
插入:insert into table1(field1,field2) values(value1,value2) NB( GE
删除:delete from table1 where 范围 '$ G%HUn
更新:update table1 set field1=value1 where 范围 9N) Ea:N
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! C8:y+pH_U;
排序:select * from table1 order by field1,field2 [desc] )^E6VD&6
总数:select count as totalcount from table1 %6@m~;c0
求和:select sum(field1) as sumvalue from table1 pf=CP%L
平均:select avg(field1) as avgvalue from table1 {gDoktC@M
最大:select max(field1) as maxvalue from table1 ^*~4[?]S
最小:select min(field1) as minvalue from table1 ?DNeL;6
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11、说明:几个高级查询运算词 UC00zW<Z@"
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A: UNION 运算符 >Y:veEa6v6
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。 (1Jc-`
B: EXCEPT 运算符 KDDx[]1Q
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。 0=OvVU;P
C: INTERSECT 运算符 Ftud6
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。 's I @es
注:使用运算词的几个查询结果行必须是一致的。 pSpxd|k
12、说明:使用外连接 #N\<(SD/
A、left outer join: #q?:Act
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。 K*j1Fy:
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 O0mQHpi:
B:right outer join: AAc2u^spx
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。 +2s][^-KV
C:full outer join: z}7U>y6`
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。 E `%*lGu_
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二、提升 m W4tW
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 6~8dMy;w
法一:select * into b from a where 1<>1 k~$}&O
法二:select top 0 * into b from a M:K4o%
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) SR9M:%dga
insert into b(a, b, c) select d,e,f from b; #)KQ-x,
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) P?iQ{x}w~
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 93Qx+oK]
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. xn7bb[g;
4、说明:子查询(表名1:a 表名2:b) U }}E
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select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) NX<Q}3cC
5、说明:显示文章、提交人和最后回复时间 n(Ry~Xu_
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b [>kzQYT[
6、说明:外连接查询(表名1:a 表名2:b) Yb>A?@S
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c bLz('mUY
7、说明:在线视图查询(表名1:a ) v,c:cKj
select * from (SELECT a,b,c FROM a) T where t.a > 1; `%0k\,}V
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 8uetv
select * from table1 where time between time1 and time2 ,aSK L1
select a,b,c, from table1 where a not between 数值1 and 数值2 sRGIHT#
9、说明:in 的使用方法 V"sm+0J
select * from table1 where a [not] in ('值1','值2','值4','值6') QPsvc6ds
10、说明:两张关联表,删除主表中已经在副表中没有的信息 k=5v
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delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) t$U eks
11、说明:四表联查问题: +r__>V,
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 ..... 5cC)&}I
12、说明:日程安排提前五分钟提醒 %0eVm
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 p{rzP,Pb&
13、说明:一条sql 语句搞定数据库分页 *3!ixDX[r
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 4=hz4(5a
14、说明:前10条记录 YR68'Sft[
select top 10 * form table1 where 范围 GG`;c?d@
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.) =xHzhh
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 7C^W <SUo
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 '\B!1B>T
(select a from tableA ) except (select a from tableB) except (select a from tableC) +}!FP3KgT
17、说明:随机取出10条数据 AaJnRtBS~
select top 10 * from tablename order by newid() xy<)zKp
18、说明:随机选择记录 \F),SL
select newid() _~E_#cNn
19、说明:删除重复记录 _VAX~Y]
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ltG|#(
20、说明:列出数据库里所有的表名 k|_LF[* Z
select name from sysobjects where type='U' ^9*Jz{e
21、说明:列出表里的所有的 ?rububDT{
select name from syscolumns where id=object_id('TableName') nA XWbavY
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。 7
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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 ~C ;gEE-
显示结果: EcmyY,w
type vender pcs 1cPjgBxv#
电脑 A 1 qu0dWgK
电脑 A 1 q8fnUK?i
光盘 B 2 j2,w1f}T
光盘 A 2 NpxND0
手机 B 3 ~-2q3U Py
手机 C 3 -D,kL
23、说明:初始化表table1 JAcNjzL
TRUNCATE TABLE table1 e!O:z
24、说明:选择从10到15的记录 n%:&N
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc ;"DI)hdz
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三、技巧 }VXZM7@u
1、1=1,1=2的使用,在SQL语句组合时用的较多 /7XVr"R
"where 1=1" 是表示选择全部 "where 1=2"全部不选, u1i
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如: ++M%PF [
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if @strWhere !='' Z "g6z#L&
begin 6I$:mHEhd
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere /c-%+Xd
end nL-kBW Ed>
else -&_;x&k
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begin +^@6{1
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 5NAB^&{Z<X
end Cr$8\{2OA7
我们可以直接写成 c9N5c
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere V(6ovJpA0
2、收缩数据库 !mRDzr7
--重建索引 3k?|-js
DBCC REINDEX S.A|(?x
DBCC INDEXDEFRAG !V;glx[
--收缩数据和日志 >>HC|
DBCC SHRINKDB >qjV(_?F-
DBCC SHRINKFILE [i)G:8U
3、压缩数据库 9jTm g%
dbcc shrinkdatabase(dbname) Z }Z]["q
4、转移数据库给新用户以已存在用户权限 *f( e`3E
exec sp_change_users_login 'update_one','newname','oldname' }=JuC+#~n
go 05Go*QvV
5、检查备份集 rA#Ji~
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' Y!L<&
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6、修复数据库 G .k\N(l
ALTER DATABASE [dvbbs] SET SINGLE_USER [I7([l1Wvd
GO #^&.*'z%z
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK
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GO ,2_!hm/
ALTER DATABASE [dvbbs] SET MULTI_USER @je vY81)
GO %oEvp{I
7、日志清除 x$\w^h\F
SET NOCOUNT ON h|t\rV^
DECLARE @LogicalFileName sysname,
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@MaxMinutes INT, xK C{P{:
@NewSize INT @Tg +Kt
USE tablename -- 要操作的数据库名 eMV@er|
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 8|iMD1
@MaxMinutes = 10, -- Limit on time allowed to wrap log. sz+Uq]Mn
@NewSize = 1 -- 你想设定的日志文件的大小(M) VyL|d^'f_
-- Setup / initialize J?N9*ap)
DECLARE @OriginalSize int o@g/,V $
SELECT @OriginalSize = size s.G6?1VXlY
FROM sysfiles jW!)5(B[A
WHERE name = @LogicalFileName &SE+7HXw
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 5!)_"u3
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + oc3}L^aD
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' (N25.}8Y
FROM sysfiles '=eE6=m^K
WHERE name = @LogicalFileName <FFaaGiE>
CREATE TABLE DummyTrans @:"GgkyDl#
(DummyColumn char (8000) not null) koAM",5D
DECLARE @Counter INT, jIs2R3B
@StartTime DATETIME, y?s8UEC
@TruncLog VARCHAR(255) mjz<,s`D
SELECT @StartTime = GETDATE(), '+{dr\nJ
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' l]o)KM<
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 6C|]Fm
EXEC (@TruncLog) 'uOzC"_yF
-- Wrap the log if necessary. \4e6\6 +
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired nmrYB w>
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) %[C-KQH
AND (@OriginalSize * 8 /1024) > @NewSize 3V`.<
BEGIN -- Outer loop. _z3YB
SELECT @Counter = 0 `Gp!Y
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) _C97G&
BEGIN -- update N>}2&'I
INSERT DummyTrans VALUES ('Fill Log') [5Dg%?x
DELETE DummyTrans #UpxF?A(
SELECT @Counter = @Counter + 1 az2CFd^M
END ?nAKB5=
EXEC (@TruncLog) a\PvRW*I
END M :Aik&
SELECT 'Final Size of ' + db_name() + ' LOG is ' + JKsdPW<?
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + d4#Ra%
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' d@72z r
FROM sysfiles ^BFD -p
WHERE name = @LogicalFileName 0fTEb%z8
DROP TABLE DummyTrans !bi}9w
SET NOCOUNT OFF 9k@`{+wmZ
8、说明:更改某个表 X519}
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exec sp_changeobjectowner 'tablename','dbo' Qb;5:U/x
9、存储更改全部表 g6. =(je
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch 32sb$|eQq
@OldOwner as NVARCHAR(128), KVrK:W--p
@NewOwner as NVARCHAR(128) mTW@E#)n
AS `1[GY){?)
DECLARE @Name as NVARCHAR(128) bu2'JIDR
DECLARE @Owner as NVARCHAR(128) t[ZumQ@HC
DECLARE @OwnerName as NVARCHAR(128) !F|iL
DECLARE curObject CURSOR FOR k5@_8Rc
select 'Name' = name, dIR6dI
'Owner' = user_name(uid) #`0iN+qh
from sysobjects 7o4 vf~
where user_name(uid)=@OldOwner rGe^$!QB
order by name ^{W#ut>IN
OPEN curObject cs%NsnZ
FETCH NEXT FROM curObject INTO @Name, @Owner '0xJp|[xVP
WHILE(@@FETCH_STATUS=0) (Q$]X5L
BEGIN }bs2Rxkh
if @Owner=@OldOwner cCj pQ
begin A<&:-Zz
set @OwnerName = @OldOwner + '.' + rtrim(@Name) E+&]96*Lby
exec sp_changeobjectowner @OwnerName, @NewOwner ewn/@;E
end |UO1v A@
-- select @name,@NewOwner,@OldOwner 2.K"+%
FETCH NEXT FROM curObject INTO @Name, @Owner {mp;^/O`er
END (qP !x 2j
close curObject 0P_Y6w+
deallocate curObject nAp7X-t
GO 4D/mm(2d$
10、SQL SERVER中直接循环写入数据 >)N}V'9
declare @i int Lz
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set @i=1 RhJL`>W`
while @i<30 2,>q(M6,EA
begin
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insert into test (userid) values(@i) !!c.cv'
set @i=@i+1 Ik#>6
end KcB?[
小记存储过程中经常用到的本周,本月,本年函数 T'*.LpNP,
Dateadd(wk,datediff(wk,0,getdate()),-1) Z6cG<,DQ
Dateadd(wk,datediff(wk,0,getdate()),6) w^*jhvV%kW
Dateadd(mm,datediff(mm,0,getdate()),0) '7F`qL\/#(
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) H\kqmPl&
Dateadd(yy,datediff(yy,0,getdate()),0) tc{23Rf%
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) b* 6c.
上面的SQL代码只是一个时间段 NRKAEf_#w
Dateadd(wk,datediff(wk,0,getdate()),-1) uREc9z`Q'
Dateadd(wk,datediff(wk,0,getdate()),6) t3/!esay
就是表示本周时间段. omV.Qb'NS
下面的SQL的条件部分,就是查询时间段在本周范围内的: Dz&4za+{
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) b)u9#%Q
而在存储过程中 d]e`t"Aj
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) <C4^Vem
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) X/1Z9a+W