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。 E,"btBg
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一、基础 RowiSW
1、说明:创建数据库 Hh;6B!zb+
CREATE DATABASE database-name :;WDPRx
2、说明:删除数据库 Eg29|)qsz
drop database dbname :aqskeT
3、说明:备份sql server EM
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--- 创建 备份数据的 device Ahbu >LPk
USE master X|1YGZJ
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' Ry S{@=si
--- 开始 备份 @d^h/w
BACKUP DATABASE pubs TO testBack gI5nWEM0{
4、说明:创建新表 "3 oU
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create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 7-IeJ6,D
根据已有的表创建新表: :@Dos'0Px
A:create table tab_new like tab_old (使用旧表创建新表) 'I>#0VRr
B:create table tab_new as select col1,col2... from tab_old definition only [_hhC
5、说明:删除新表 `DllW{l
drop table tabname Bg0cC
6、说明:增加一个列 _";pk _
Alter table tabname add column col type ;/q6^Nk3A
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。 vl~
7、说明:添加主键: Alter table tabname add primary key(col) }Q^a.`h
说明:删除主键: Alter table tabname drop primary key(col) *>$)#?t
8、说明:创建索引:create [unique] index idxname on tabname(col....) [IBk-opap
删除索引:drop index idxname KL"L65g&
注:索引是不可更改的,想更改必须删除重新建。 GiwA$^Hg\
9、说明:创建视图:create view viewname as select statement _1c_TM h}9
删除视图:drop view viewname *`.{K12T
10、说明:几个简单的基本的sql语句
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选择:select * from table1 where 范围 >b?)WNk
插入:insert into table1(field1,field2) values(value1,value2) *9(1:N;#
删除:delete from table1 where 范围 jyH_/X5i7
更新:update table1 set field1=value1 where 范围 K/+C6Y?
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! SY)$2RC+}
排序:select * from table1 order by field1,field2 [desc] [gp:nxyfQm
总数:select count as totalcount from table1 Iw7r}G
求和:select sum(field1) as sumvalue from table1 I8;[DP9
平均:select avg(field1) as avgvalue from table1 i O|,,;_
最大:select max(field1) as maxvalue from table1 rg/vxTl
最小:select min(field1) as minvalue from table1 j$oZIV7
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11、说明:几个高级查询运算词 8vW`E_n
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A: UNION 运算符 :Rj,'uH+h)
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。 n1(X%%2
B: EXCEPT 运算符 &)jZ|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。 .{Oq)^!ot
C: INTERSECT 运算符 m9cT}x&j
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。 r['C.S6
注:使用运算词的几个查询结果行必须是一致的。 6|cl`}g_j
12、说明:使用外连接 DJ0T5VE W3
A、left outer join: \%Q
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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。 lB~'7r`
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 :]QxT8B
B:right outer join: oa !P]r
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。 {=7i}xY]T
C:full outer join: 1^^D :tt
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。 S
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二、提升 1u+(rVQN
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ScoHtX3
法一:select * into b from a where 1<>1 oz@6%3+
法二:select top 0 * into b from a yE,o~O
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) r/L]uSN
insert into b(a, b, c) select d,e,f from b; &:K? -ac
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) *7ro [
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ?}
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例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. {K8T5zrV
4、说明:子查询(表名1:a 表名2:b) p;=(-4\V}
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) (k&aD2PH
5、说明:显示文章、提交人和最后回复时间 0*@S-Lj^c
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b [`\Qte%UH
6、说明:外连接查询(表名1:a 表名2:b) 'FFc"lqj
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c <t37DnCgI
7、说明:在线视图查询(表名1:a ) In
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select * from (SELECT a,b,c FROM a) T where t.a > 1; ]_8 \g`"u
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 %([H*sLX
select * from table1 where time between time1 and time2 \hN2w]e
select a,b,c, from table1 where a not between 数值1 and 数值2 Z"+!ayA7D
9、说明:in 的使用方法 oF
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select * from table1 where a [not] in ('值1','值2','值4','值6') #K w\r50
10、说明:两张关联表,删除主表中已经在副表中没有的信息 V7_??L%Ct`
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) /z:K#
11、说明:四表联查问题: kq0m^`
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 ..... %WN2 xCSf
12、说明:日程安排提前五分钟提醒 pk1M.+
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 hiHp@"l<
13、说明:一条sql 语句搞定数据库分页 _I4sy=tYXK
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 dxWw%_Q
14、说明:前10条记录 =
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select top 10 * form table1 where 范围 JvaaBXkS\
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.) c.v)M\:
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) [F EQ@
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 ?s33x#
(select a from tableA ) except (select a from tableB) except (select a from tableC) gwNkjI=,
17、说明:随机取出10条数据 pj]<i.p
select top 10 * from tablename order by newid() +(%[f W
18、说明:随机选择记录 OhEL9"\<
select newid() -m/4\D
19、说明:删除重复记录 hhhO+D1(
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) e r$ 'c
20、说明:列出数据库里所有的表名 GK&Dd"v
select name from sysobjects where type='U' Dm#k-y
21、说明:列出表里的所有的 p#2th`M:P1
select name from syscolumns where id=object_id('TableName') 55p=veq \
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。 90}B*3x
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 F9W5x=EK\
显示结果: I r~X#$Upc
type vender pcs n]Y _C^
电脑 A 1 2_X0Og8s[
电脑 A 1 sf0U(XYQ^
光盘 B 2 GNOC5 E$I
光盘 A 2 O]lfs>>x
手机 B 3 <@u6*]
手机 C 3 {+Yo&F}n
23、说明:初始化表table1 Dy!fwYPA/{
TRUNCATE TABLE table1 }}_l@5
24、说明:选择从10到15的记录 qE{S'XyM,
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc ]XU#i#;c
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三、技巧 sSUd;BYf
1、1=1,1=2的使用,在SQL语句组合时用的较多 aDuanGC/V
"where 1=1" 是表示选择全部 "where 1=2"全部不选, W( YJz#]6_
如: "#jKk6{I0
if @strWhere !='' 7ZZt|bl
begin K#r`^aUc
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere -S@:
end LKcrr;
else @HI5;z
begin }R$%MU5::
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' v<1;1m
end NO^(D+9
我们可以直接写成 QUf_fe!,|
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere Gj 3/&'k6
2、收缩数据库 'Iu(lpF&
--重建索引 v*3:8Y,
DBCC REINDEX wn`budH?c8
DBCC INDEXDEFRAG 1CbC|q
--收缩数据和日志 whCv9)x
DBCC SHRINKDB pG&.Ye]j
DBCC SHRINKFILE :%{7Q$Xv<
3、压缩数据库 ikQ2x]Sp
dbcc shrinkdatabase(dbname) rNc>1}DDS
4、转移数据库给新用户以已存在用户权限 2lRZ/xaF%P
exec sp_change_users_login 'update_one','newname','oldname' B|v
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go n:P}K?lg
5、检查备份集 16vfIUtb
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' f$|v
6、修复数据库 K-ebAaiC
ALTER DATABASE [dvbbs] SET SINGLE_USER STe;Sr&p
GO $G3P3y:
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DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK h*LIS@&9C5
GO *?{)i~
ALTER DATABASE [dvbbs] SET MULTI_USER $`%.Y&A
GO /l
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7、日志清除 yrw!b\
SET NOCOUNT ON U*cj'`eqC
DECLARE @LogicalFileName sysname, _wBPn6gg`
@MaxMinutes INT, ,P^"X5$
@NewSize INT &D:88
USE tablename -- 要操作的数据库名 /NZR|
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 I8y\D,
@MaxMinutes = 10, -- Limit on time allowed to wrap log. \GWC5R7Q0j
@NewSize = 1 -- 你想设定的日志文件的大小(M) +\4=G@P.J
-- Setup / initialize DcS~@ ;
DECLARE @OriginalSize int 6%TV X
SELECT @OriginalSize = size ''G@n*
FROM sysfiles ^s5)FdF8
WHERE name = @LogicalFileName D$\ EZ
SELECT 'Original Size of ' + db_name() + ' LOG is ' + $3>|RlxYA
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + Go4l#6
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 5zU$_ M
FROM sysfiles 9V~yK?
WHERE name = @LogicalFileName C}CX n X
CREATE TABLE DummyTrans R##O9BSI8Z
(DummyColumn char (8000) not null) ZD3S|1zSQ
DECLARE @Counter INT, f4q-wX_1
@StartTime DATETIME, Jy9&=Qh
@TruncLog VARCHAR(255) 3I]5DW %-
SELECT @StartTime = GETDATE(), vsK>?5{C-
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' H
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) ZYG"nmNd
EXEC (@TruncLog) Uu
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-- Wrap the log if necessary. ~c4Y*]J
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Ae1},2py
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) [*fnTy
AND (@OriginalSize * 8 /1024) > @NewSize t1kD5^
BEGIN -- Outer loop. nP.d5%E
SELECT @Counter = 0 3hkA`YSYt
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ]^!#0(
BEGIN -- update ,M9'S;&^
INSERT DummyTrans VALUES ('Fill Log') I/'>Bn+
DELETE DummyTrans ][3 "xP
SELECT @Counter = @Counter + 1 ctf'/IZ5
END -
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EXEC (@TruncLog) SLW1]ZaG
END F)C8LH
SELECT 'Final Size of ' + db_name() + ' LOG is ' + !*p lK6a
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + :H~r
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CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' !)GPI?{^5
FROM sysfiles \>+gZc]an
WHERE name = @LogicalFileName =Oy,SX
DROP TABLE DummyTrans rS=6d6@
SET NOCOUNT OFF B$)KZR(u
8、说明:更改某个表 Epx.0TA= t
exec sp_changeobjectowner 'tablename','dbo' t;'__">:q
9、存储更改全部表 _ v-sb(*
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CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch YPN|qn(
@OldOwner as NVARCHAR(128), `|gCbs95
@NewOwner as NVARCHAR(128) /SyiJCx0
AS s;bqUY?LD
DECLARE @Name as NVARCHAR(128) @^%# ]x,:
DECLARE @Owner as NVARCHAR(128) _b+3;Dy
DECLARE @OwnerName as NVARCHAR(128) Q,scjt[
DECLARE curObject CURSOR FOR k
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select 'Name' = name, akR*|iK#b
'Owner' = user_name(uid) W*P/~U=
from sysobjects ,\VNs'j
where user_name(uid)=@OldOwner #]9yzyb_y
order by name .NjOaK)\
OPEN curObject ST{<G
FETCH NEXT FROM curObject INTO @Name, @Owner \eN }V
WHILE(@@FETCH_STATUS=0) IlH*s/
BEGIN 5z0SjQ
if @Owner=@OldOwner by-B).7
begin
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set @OwnerName = @OldOwner + '.' + rtrim(@Name) ,$*$w<
exec sp_changeobjectowner @OwnerName, @NewOwner 'E9\V\bi
end rKO[;]_*
-- select @name,@NewOwner,@OldOwner ^+-i7`|=
FETCH NEXT FROM curObject INTO @Name, @Owner &Oe,$%{hBh
END 1&U U6| X
close curObject VQ+Xh
deallocate curObject %.]qkGZe#
GO +ft?aB@
10、SQL SERVER中直接循环写入数据 =h4XsV)rO
declare @i int ;:v:pg8qc
set @i=1 d35 ,[
while @i<30 %GJ,&b|
begin B7cXbUAQs
insert into test (userid) values(@i) By"
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set @i=@i+1 a4c~ThbI
end l/Sb JrM*
小记存储过程中经常用到的本周,本月,本年函数 ondF
Dateadd(wk,datediff(wk,0,getdate()),-1) nP] ~8ViS
Dateadd(wk,datediff(wk,0,getdate()),6) Uc.K6%iI
Dateadd(mm,datediff(mm,0,getdate()),0) \ZXH(N*>2t
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) 7Kfh:0Ihhy
Dateadd(yy,datediff(yy,0,getdate()),0) l2xM.vR
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) <J\z6+,4E
上面的SQL代码只是一个时间段 tip\vS)
Dateadd(wk,datediff(wk,0,getdate()),-1) n<?:!f`
Dateadd(wk,datediff(wk,0,getdate()),6) <~'\~Z d+
就是表示本周时间段. t|1?mH9
下面的SQL的条件部分,就是查询时间段在本周范围内的: W@#Y/L:${
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) %;GDg3L[p
而在存储过程中 /aP`|&G,)
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) DvU(rr\p
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ^MuO;<<,.