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。 `Re{j{~s
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一、基础 mhv ;pM6
1、说明:创建数据库 jG^f_w
CREATE DATABASE database-name ^$x1~}D
2、说明:删除数据库 M'sq{K9
drop database dbname "wj~KbT}&
3、说明:备份sql server H9Dw#.em
--- 创建 备份数据的 device ~gA^tc3G
USE master W6!o=()
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' "x4}FQ
--- 开始 备份 T%TfkQ__d
BACKUP DATABASE pubs TO testBack ]x1o (~
4、说明:创建新表 SFkB,)Z N
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) $X ]t}=
根据已有的表创建新表: go!jx6~;x
A:create table tab_new like tab_old (使用旧表创建新表) uMb[0-5
B:create table tab_new as select col1,col2... from tab_old definition only =EQaZ8k
5、说明:删除新表 rk7d7`V
drop table tabname }Q-%ij2
6、说明:增加一个列 ^tRy6zG
Alter table tabname add column col type l",X
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 iVZX
7、说明:添加主键: Alter table tabname add primary key(col) o!Y61S(
说明:删除主键: Alter table tabname drop primary key(col) xWxgv;Ah
8、说明:创建索引:create [unique] index idxname on tabname(col....) Sh;Z\nj
删除索引:drop index idxname u_'XUJ32!
注:索引是不可更改的,想更改必须删除重新建。 )tp;2rJ/
9、说明:创建视图:create view viewname as select statement eEZZ0NNe;
删除视图:drop view viewname {D`_q|
10、说明:几个简单的基本的sql语句 s#4Q?<65u
选择:select * from table1 where 范围 %j.
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插入:insert into table1(field1,field2) values(value1,value2) -40s
删除:delete from table1 where 范围 9w}_CCj3
更新:update table1 set field1=value1 where 范围 X(qs]:
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! rvG0aqO`
排序:select * from table1 order by field1,field2 [desc] N+CcWs!E
总数:select count as totalcount from table1 z"$huE>P6
求和:select sum(field1) as sumvalue from table1 >)8<d3m
平均:select avg(field1) as avgvalue from table1 =
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最大:select max(field1) as maxvalue from table1 WJBwo%J
最小:select min(field1) as minvalue from table1 z:W|GDD1
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11、说明:几个高级查询运算词 `^'0__<M
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A: UNION 运算符 SS7C|*-Zd
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。 $m[*)0/
B: EXCEPT 运算符 UYkuz
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 U`kO<ztk
C: INTERSECT 运算符 gI{56Z
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 Sp./*h\}
注:使用运算词的几个查询结果行必须是一致的。 "Ax#x
12、说明:使用外连接 p.RSH$]
A、left outer join: wY{!gQ
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。 6>F1!Q
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 .,&6 x.
B:right outer join: IiZXIG4H
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。 *zl-R*bM$
C:full outer join: <hB~|a<#
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。 ~4=XYYcka
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二、提升 sHm:G_
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) CW'<Nh
法一:select * into b from a where 1<>1 4R28S]Gb
法二:select top 0 * into b from a JK^pb0ih
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) JTdcLmL
insert into b(a, b, c) select d,e,f from b; m?O"LGBB=
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) K?gO]T{6
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 #|;;>YnZ
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. y2:Bv2}
4、说明:子查询(表名1:a 表名2:b) 6bd{3@
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) N7#,x9+E
5、说明:显示文章、提交人和最后回复时间 yq,%<%+
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b .v[!_bk8C
6、说明:外连接查询(表名1:a 表名2:b) Cg&:+
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ~09k IO)
7、说明:在线视图查询(表名1:a ) Hr!%L*h?
select * from (SELECT a,b,c FROM a) T where t.a > 1; 5Tiap8x+<
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 TykY> cl
select * from table1 where time between time1 and time2 KYC<*1k
select a,b,c, from table1 where a not between 数值1 and 数值2 U{PFeR,Uk
9、说明:in 的使用方法 9ve)+Lk
select * from table1 where a [not] in ('值1','值2','值4','值6') R/ 3#(5
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':0
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) Oi$$vjs2
11、说明:四表联查问题: C`b)}dY
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 ..... gM_MK8py
12、说明:日程安排提前五分钟提醒 }-%:!*bLj
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 i?IV"*Ob1N
13、说明:一条sql 语句搞定数据库分页 mL3 Q
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 3Nk
)
14、说明:前10条记录 U~_G *0
select top 10 * form table1 where 范围 ?Suv.!wfLl
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.) ](SqLTB+?
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ]tc
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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 GpGq' 8|(
(select a from tableA ) except (select a from tableB) except (select a from tableC) 0uhIJc'2
17、说明:随机取出10条数据 O+PRP"$g"
select top 10 * from tablename order by newid() ?RU_SCp-
18、说明:随机选择记录 ,Laz515
select newid() 2hFOwI
19、说明:删除重复记录 4S*7*ak{
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) <c]?
20、说明:列出数据库里所有的表名 LhQidvCNJ
select name from sysobjects where type='U' 8rM1kOCf
21、说明:列出表里的所有的 @h)X3X
select name from syscolumns where id=object_id('TableName') j\TS:F^z
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 Lo
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select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type Qvm[2mb
显示结果: ~RIa),GVX
type vender pcs ?oulQR6:
电脑 A 1 M<cm]
电脑 A 1 Q)ZbnR2Z8
光盘 B 2 %lqrq<Xn
光盘 A 2 _0!<iN L
手机 B 3 [J+]1hCZ|
手机 C 3 "Tc[1{eI
23、说明:初始化表table1 W=zp:6Z~
TRUNCATE TABLE table1 %nT &
24、说明:选择从10到15的记录 YA*E93 J0
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc >|_B=<!99W
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三、技巧 8e}8@[h
1、1=1,1=2的使用,在SQL语句组合时用的较多 ( Y)a`[B
"where 1=1" 是表示选择全部 "where 1=2"全部不选, n_1,-(t
如: zJT,Hv .
if @strWhere !='' cDqj&:$e
begin 66MWOrr
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere 0]MI*s>&
end Su/}OS\R
else THHA~;00YN
begin axLO: Q,
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' C5&+1VrP
end _Rey~]iJJ8
我们可以直接写成 +8|r_z\A5a
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere /<it2=
2、收缩数据库 Zm#qW2a]P
--重建索引 Y"'k $jS-
DBCC REINDEX %a$Fsn
DBCC INDEXDEFRAG 'QxPQcU
--收缩数据和日志 5HMDug;
DBCC SHRINKDB ~R\U1XXyUY
DBCC SHRINKFILE vp..>BMJ
3、压缩数据库 ]-tAgNzl%
dbcc shrinkdatabase(dbname) 5 @61=Au
4、转移数据库给新用户以已存在用户权限 @ )m9#F
exec sp_change_users_login 'update_one','newname','oldname' jS'hs>Ot
go hv8j$2m
5、检查备份集 ^9xsbv
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RESTORE VERIFYONLY from disk='E:\dvbbs.bak' (h>+ivf|
6、修复数据库 -[-Ry6G
ALTER DATABASE [dvbbs] SET SINGLE_USER 2W q/_:
GO u}BN)%`B
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK hP26 Bb1
GO :j(D&?ao
ALTER DATABASE [dvbbs] SET MULTI_USER Z=CY6Zu7
GO C;.+ kE
7、日志清除 s&~.";b
SET NOCOUNT ON d&5GkD.P
DECLARE @LogicalFileName sysname, O!.mc=Gx7
@MaxMinutes INT, 3:G94cp5
@NewSize INT kU$M 8J.
USE tablename -- 要操作的数据库名 )0xEI
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 aIABx!83>
@MaxMinutes = 10, -- Limit on time allowed to wrap log. NZ?| #53
@NewSize = 1 -- 你想设定的日志文件的大小(M) TM1J1GU
-- Setup / initialize `8N],X
DECLARE @OriginalSize int <|_b:
SELECT @OriginalSize = size :z}
FROM sysfiles M}W};~V2ng
WHERE name = @LogicalFileName tx{tIw^2;
SELECT 'Original Size of ' + db_name() + ' LOG is ' + i=8){GX4
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 8GFA}_(^R
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ZeYkZzN
FROM sysfiles ;
#^Jy#)
WHERE name = @LogicalFileName }^ G&n';J
CREATE TABLE DummyTrans _HkB+D0v
(DummyColumn char (8000) not null) }%I)bU
DECLARE @Counter INT, 9\[A%jp#K@
@StartTime DATETIME,
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@TruncLog VARCHAR(255) <u85>x
SELECT @StartTime = GETDATE(), kFF)6z:2
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' W_z?t;
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ^7&0Pm
EXEC (@TruncLog) yyVv@
-- Wrap the log if necessary. 2gb MUdpp
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ~TEKxgU
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName)
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AND (@OriginalSize * 8 /1024) > @NewSize _Q3Ad>,U
BEGIN -- Outer loop. A`qb5LLJ)
SELECT @Counter = 0 2e @zd\
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) |`yzH$,F
BEGIN -- update ewb/Z[4
INSERT DummyTrans VALUES ('Fill Log') ]VS$ ?wD
DELETE DummyTrans =\l7k<
SELECT @Counter = @Counter + 1 ;
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END o4g<[X)
EXEC (@TruncLog) 9Ucn
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END MOEB{~v`;
SELECT 'Final Size of ' + db_name() + ' LOG is ' + HJ,sZ4*]]
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 9p5{,9 .3*
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' I+^B] @"
FROM sysfiles OY/sCx+c
WHERE name = @LogicalFileName @43o4,
DROP TABLE DummyTrans [F<Tl =
SET NOCOUNT OFF 3e.v'ccK&
8、说明:更改某个表 bs_"Nn?
exec sp_changeobjectowner 'tablename','dbo' dQ4K^u
9、存储更改全部表 'of5v6:8
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch v|v^(P,o
@OldOwner as NVARCHAR(128), \PB ~6
@NewOwner as NVARCHAR(128) 044*@a5f
AS [ZP8[Zl'?
DECLARE @Name as NVARCHAR(128) jW-j+WGSM
DECLARE @Owner as NVARCHAR(128) (SlrV8;
DECLARE @OwnerName as NVARCHAR(128) gB?~!J?
DECLARE curObject CURSOR FOR {!C ';^
select 'Name' = name, boR&'yX
'Owner' = user_name(uid) tT;=l[7%
from sysobjects p8q9:Tz
where user_name(uid)=@OldOwner $N#f)8v
order by name Gv,0{DVX<
OPEN curObject ]'UO]i/
FETCH NEXT FROM curObject INTO @Name, @Owner 2eBA&t
WHILE(@@FETCH_STATUS=0) c=T^)~$$
BEGIN o(/(`/
if @Owner=@OldOwner {A2SG#}
begin 6*,8 H&
set @OwnerName = @OldOwner + '.' + rtrim(@Name) sgn,]3AUq
exec sp_changeobjectowner @OwnerName, @NewOwner ]<;m;/H
end Svmyg]
-- select @name,@NewOwner,@OldOwner b:}`O!UBw
FETCH NEXT FROM curObject INTO @Name, @Owner ?wR;"
END wxg`[c$:
close curObject 3 9Ql|l$
deallocate curObject fFfH9 cl!
GO 2>l:: 8Pp
10、SQL SERVER中直接循环写入数据 Odr@9MJ
declare @i int Upr:sB
set @i=1 61Nj&1Ze
while @i<30 $e|G#mMd-
begin OT9\K_
insert into test (userid) values(@i) {q1&4U~'>O
set @i=@i+1 S4]xxc
end u|=G#y;3
小记存储过程中经常用到的本周,本月,本年函数
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Dateadd(wk,datediff(wk,0,getdate()),-1) b-{\manH
Dateadd(wk,datediff(wk,0,getdate()),6) ,0#5kc*X
Dateadd(mm,datediff(mm,0,getdate()),0) 26E"Ui5q
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) .d5|Fs~B
Dateadd(yy,datediff(yy,0,getdate()),0) Mc9P(5Bf
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) _gY
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上面的SQL代码只是一个时间段 KZL5>E
Dateadd(wk,datediff(wk,0,getdate()),-1) @$~ BU;kR
Dateadd(wk,datediff(wk,0,getdate()),6) X?b]5?K;r
就是表示本周时间段. &
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下面的SQL的条件部分,就是查询时间段在本周范围内的: Hm+-gI3*
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ,XW6W&vR;
而在存储过程中 R.R(|!w>
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) fz
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select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 2FO.!m