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。 V$OZC;4
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一、基础 } ={TVs^
1、说明:创建数据库 s28t'
CREATE DATABASE database-name &-e@Et`Pg
2、说明:删除数据库 K*"Wq:T;B
drop database dbname V DN@=/
3、说明:备份sql server Gt|m;o
--- 创建 备份数据的 device OQ=0>;>
USE master cT&!_g#g
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' :_0"t-
--- 开始 备份 655OL)|cD6
BACKUP DATABASE pubs TO testBack IH2V.>h
4、说明:创建新表 3=@lJ?Ym
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) A
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根据已有的表创建新表: GE S_|[Q
A:create table tab_new like tab_old (使用旧表创建新表) 4lCEzWo[/
B:create table tab_new as select col1,col2... from tab_old definition only XCAy _fL<B
5、说明:删除新表 Mtw7aK
drop table tabname |<2g^ZK)
6、说明:增加一个列 :U{$G(
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Alter table tabname add column col type GJeP~
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。 <F%c"Rkh
7、说明:添加主键: Alter table tabname add primary key(col) #'qDNY@ w}
说明:删除主键: Alter table tabname drop primary key(col) 7]J7'!Iz
8、说明:创建索引:create [unique] index idxname on tabname(col....) $URL7hrhU
删除索引:drop index idxname (H[.\O-`
注:索引是不可更改的,想更改必须删除重新建。 K5"8zF)*
9、说明:创建视图:create view viewname as select statement &;x*uG
删除视图:drop view viewname kWZ@v+Mk3
10、说明:几个简单的基本的sql语句 ;Yr?"|
选择:select * from table1 where 范围 1*VArr6*6
插入:insert into table1(field1,field2) values(value1,value2) 2d60o~E
删除:delete from table1 where 范围 e$t$,3~
更新:update table1 set field1=value1 where 范围 jl)7Jd
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! =^5,ua6
排序:select * from table1 order by field1,field2 [desc] {0Jpf[.f
总数:select count as totalcount from table1 J? 4E Hl
求和:select sum(field1) as sumvalue from table1 L\%zNPLS
平均:select avg(field1) as avgvalue from table1 wRj||yay#-
最大:select max(field1) as maxvalue from table1 N"zg)MsX
最小:select min(field1) as minvalue from table1 EvJ<X,Bo
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11、说明:几个高级查询运算词 +U^H`\EUr
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A: UNION 运算符 -TT{4\%s
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 YLU.]UC
B: EXCEPT 运算符 . l>.
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 :|z.F+-/
C: INTERSECT 运算符 =cwdl7N&I
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 =3H*%
注:使用运算词的几个查询结果行必须是一致的。 W>'KE:!sp
12、说明:使用外连接 K @h94Ni6
A、left outer join: 8bf~uHAr
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 ^U.t5jj
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c PHh4ZFl]_I
B:right outer join:
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右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 o+%($p
C:full outer join: tVr^1Y
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。
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二、提升 QP~Iz*J'
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) E
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法一:select * into b from a where 1<>1 =#.qe=
法二:select top 0 * into b from a }J0HEpn4
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) @p2XaqZ
insert into b(a, b, c) select d,e,f from b; ]ddTHl
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) yLY$1#Sa
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 1x3>XN]a
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 9:4m@dguh-
4、说明:子查询(表名1:a 表名2:b) T$&vk#qr
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) KfkU_0R+~v
5、说明:显示文章、提交人和最后回复时间 vo!QJ
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 9 .3?$(
6、说明:外连接查询(表名1:a 表名2:b) 1> 'xmp+#
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c -E+LA
7、说明:在线视图查询(表名1:a ) zS/1v+
select * from (SELECT a,b,c FROM a) T where t.a > 1; VC.zmCglo^
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 XbYST%|.
select * from table1 where time between time1 and time2 E06)&tF
select a,b,c, from table1 where a not between 数值1 and 数值2 UPGS/Xs]1
9、说明:in 的使用方法 s)-O{5;U
select * from table1 where a [not] in ('值1','值2','值4','值6') j9g0k<eg
10、说明:两张关联表,删除主表中已经在副表中没有的信息 ?d5_{*]+v
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 8 \Uy
11、说明:四表联查问题: gaC[%M
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... iu.$P-s
12、说明:日程安排提前五分钟提醒 =jD9oMs
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 E/{v6S{)Y
13、说明:一条sql 语句搞定数据库分页 4OTrMT$y
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 D0*+7n3
14、说明:前10条记录 &, %+rvo}
select top 10 * form table1 where 范围 +8Q5[lh2]j
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) "Gc\"'^r
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) DPBWw[
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 a2. @Zyz
(select a from tableA ) except (select a from tableB) except (select a from tableC) m_C#fR /I
17、说明:随机取出10条数据 \L:+k `
select top 10 * from tablename order by newid() Sh;Z\nj
18、说明:随机选择记录 u_'XUJ32!
select newid() B{2WvPX~q
19、说明:删除重复记录 eEZZ0NNe;
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) {D`_q|
20、说明:列出数据库里所有的表名 s#4Q?<65u
select name from sysobjects where type='U' g..&x]aS(
21、说明:列出表里的所有的 qE@H~&
select name from syscolumns where id=object_id('TableName') -40s
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 ::k
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select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type 9w}_CCj3
显示结果: X(qs]:
type vender pcs ]\6*2E{1m
电脑 A 1 N+CcWs!E
电脑 A 1 z"$huE>P6
光盘 B 2 [ n2)6B\/
光盘 A 2 =
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手机 B 3 WJBwo%J
手机 C 3 z:W|GDD1
23、说明:初始化表table1 ,#8H9<O9t
TRUNCATE TABLE table1 .-?Txkwb
24、说明:选择从10到15的记录 kB]?95>Wx
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc `^'0__<M
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三、技巧 $m[*)0/
1、1=1,1=2的使用,在SQL语句组合时用的较多 UYkuz
"where 1=1" 是表示选择全部 "where 1=2"全部不选, U`kO<ztk
如: gI{56Z
if @strWhere !='' Sp./*h\}
begin "Ax#x
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ofy)}/i
end wY{!gQ
else 6>F1!Q
begin miEf<<L#z
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' (&oT6Ji
end *zl-R*bM$
我们可以直接写成 >fx/TSql:J
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere UdK +,k~m/
2、收缩数据库 G4{TJ,~
--重建索引 XEb+Z7L 1
DBCC REINDEX 6T-iBJT
DBCC INDEXDEFRAG QB6.
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--收缩数据和日志 3 adF) mh
DBCC SHRINKDB %Zi}sm1t
DBCC SHRINKFILE 3&5AbIZ
3、压缩数据库 wd<jh,Y
dbcc shrinkdatabase(dbname) KD73Aw
4、转移数据库给新用户以已存在用户权限 N51WY7
exec sp_change_users_login 'update_one','newname','oldname' I!Uj~jV
go |v@ zyOq&b
5、检查备份集 U{ZKxE
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' (Z#j^}G_l
6、修复数据库 {9|S,<9
ALTER DATABASE [dvbbs] SET SINGLE_USER Q'c[yu
GO 5Tiap8x+<
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 0khAi|PY
GO KYC<*1k
ALTER DATABASE [dvbbs] SET MULTI_USER U{PFeR,Uk
GO 8c' 5P
7、日志清除 )(W%Hmi
SET NOCOUNT ON H':0
DECLARE @LogicalFileName sysname, bw*D!mm,
@MaxMinutes INT, ~'t+X
@NewSize INT gM_MK8py
USE tablename -- 要操作的数据库名 :8l#jU`y
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ]:Sb#=,!&!
@MaxMinutes = 10, -- Limit on time allowed to wrap log. mL3 Q
@NewSize = 1 -- 你想设定的日志文件的大小(M) 3Nk
)
-- Setup / initialize ?7Skk
DECLARE @OriginalSize int ?Suv.!wfLl
SELECT @OriginalSize = size E#/vgm=W;
FROM sysfiles (&xIBF_6
WHERE name = @LogicalFileName tN-B`d1
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 0s%]%2ON
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + &U{"dJ r
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 'aJm4W&j
FROM sysfiles KJCi4O&
WHERE name = @LogicalFileName ?jHu,
CREATE TABLE DummyTrans d;E
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(DummyColumn char (8000) not null) ^=,N]
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DECLARE @Counter INT, L,*#
@StartTime DATETIME, "= >8UR
@TruncLog VARCHAR(255) _2rxDd1#.
SELECT @StartTime = GETDATE(), EQ2HQz]
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' v0,&wdi
DBCC SHRINKFILE (@LogicalFileName, @NewSize) O^<\]_l
EXEC (@TruncLog)
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-- Wrap the log if necessary. cPg$*,]
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired H;Cv]-
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) k*o>ZpjNH
AND (@OriginalSize * 8 /1024) > @NewSize 2br~Vn0N
BEGIN -- Outer loop. Ahrtl6@AS
SELECT @Counter = 0 rj-Q+rgup
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) FXo{|z3
BEGIN -- update *>J45U(6:
INSERT DummyTrans VALUES ('Fill Log') "<1-9CMl
DELETE DummyTrans Vo(V<2lw}
SELECT @Counter = @Counter + 1 _NB8>v
END _[8sL^
EXEC (@TruncLog) $[g8j`or!
END 4KZ)`KPE
SELECT 'Final Size of ' + db_name() + ' LOG is ' + &8@
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CONVERT(VARCHAR(30),size) + ' 8K pages or ' + *Fz#x{zt
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' Ufv0Xj
FROM sysfiles f$]ttU U
WHERE name = @LogicalFileName </33>Fu)
DROP TABLE DummyTrans ( Y)a`[B
SET NOCOUNT OFF (m&''yaH
8、说明:更改某个表 :my@Oxx4@
exec sp_changeobjectowner 'tablename','dbo' ZY-mUg
9、存储更改全部表 V(<(k,8=
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch .tt= \R
@OldOwner as NVARCHAR(128), wZ\% !#}7
@NewOwner as NVARCHAR(128) CpdQ]Ai[
AS A^@,Ha
DECLARE @Name as NVARCHAR(128) VQHQvFRZ)
DECLARE @Owner as NVARCHAR(128) x(bM
DECLARE @OwnerName as NVARCHAR(128) (5&l<u"K~
DECLARE curObject CURSOR FOR Xr$hQbl5D
select 'Name' = name, d{~Qd|<rr
'Owner' = user_name(uid) g%2twq_
from sysobjects :IX_}|
where user_name(uid)=@OldOwner cvO;xR
order by name .Af H>)E
OPEN curObject #Q$`3rr
FETCH NEXT FROM curObject INTO @Name, @Owner |
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WHILE(@@FETCH_STATUS=0) ,7*-%05[\
BEGIN ) kK" 1\m
if @Owner=@OldOwner vp..>BMJ
begin Wkc^?0p
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 2~q(?wY
exec sp_changeobjectowner @OwnerName, @NewOwner R4Si{J*O
end 9Li.B1j
-- select @name,@NewOwner,@OldOwner _~_6qTv-d
FETCH NEXT FROM curObject INTO @Name, @Owner 6HxZS+],c
END kJ:zMVN
close curObject l$eKV(CZ4
deallocate curObject <]kifiN#
GO ?8aPd"x
10、SQL SERVER中直接循环写入数据 jG~UyzWH;
declare @i int u(P;) E"1
set @i=1 rBovC
while @i<30 <n|.Z-gF\
begin Q5pm^X._j
insert into test (userid) values(@i) jN^09T49
set @i=@i+1 ,Z p9,nf
end
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小记存储过程中经常用到的本周,本月,本年函数 NzuH&o][
Dateadd(wk,datediff(wk,0,getdate()),-1) :h)A/k_
Dateadd(wk,datediff(wk,0,getdate()),6) E!v^j=h$u
Dateadd(mm,datediff(mm,0,getdate()),0) Mq2[^l!qu
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) Trwk9 +
Dateadd(yy,datediff(yy,0,getdate()),0) G?QU|<mj<
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) VKXZA2<?'
上面的SQL代码只是一个时间段 DsH`I%w{
Dateadd(wk,datediff(wk,0,getdate()),-1) `-[+(+["
Dateadd(wk,datediff(wk,0,getdate()),6) LTt|"D
就是表示本周时间段. 1$adX
下面的SQL的条件部分,就是查询时间段在本周范围内的: }^ G&n';J
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) _HkB+D0v
而在存储过程中 B^sHFc""V
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 9\[A%jp#K@
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6)
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