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。 6$b"tdP
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一、基础 Cfb/f]*M
1、说明:创建数据库 t[F tIj6
CREATE DATABASE database-name vBQ5-00YY=
2、说明:删除数据库 2,;+)
drop database dbname +*d,non6v
3、说明:备份sql server p H?VM&x
--- 创建 备份数据的 device RWXj)H)w
USE master @=b0>^\m
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' As1Er[>
--- 开始 备份 aM3%Mx?w
BACKUP DATABASE pubs TO testBack f| 3`8JU
4、说明:创建新表 =2)5_/9au
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) OsAXHjX}
根据已有的表创建新表: czb(&><
A:create table tab_new like tab_old (使用旧表创建新表) QO7> XHn
B:create table tab_new as select col1,col2... from tab_old definition only Yq#I#
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5、说明:删除新表 y^hpmTB3"
drop table tabname lVXgp'!#j
6、说明:增加一个列 1U~AupHE
Alter table tabname add column col type -Z<e`iFQS
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 n@5pS3qZ
7、说明:添加主键: Alter table tabname add primary key(col) brNe13d3~"
说明:删除主键: Alter table tabname drop primary key(col) V@84Cb
8、说明:创建索引:create [unique] index idxname on tabname(col....) usR19 _E-
删除索引:drop index idxname z>&Py(
注:索引是不可更改的,想更改必须删除重新建。 #:vos VqG
9、说明:创建视图:create view viewname as select statement WMZa6cH
删除视图:drop view viewname =q^o6{d0"
10、说明:几个简单的基本的sql语句 =5%jKHo+9z
选择:select * from table1 where 范围 ~5`rv1$
插入:insert into table1(field1,field2) values(value1,value2) g 6>RyjN
删除:delete from table1 where 范围 l?a(=
更新:update table1 set field1=value1 where 范围 ,<|EoravH
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! )dJM
排序:select * from table1 order by field1,field2 [desc] Nt&}T
总数:select count as totalcount from table1 R/b)h P~
求和:select sum(field1) as sumvalue from table1 I4
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平均:select avg(field1) as avgvalue from table1 )wpBxJ;dB}
最大:select max(field1) as maxvalue from table1 /+sn-$/"i
最小:select min(field1) as minvalue from table1 iyu%o9_0
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11、说明:几个高级查询运算词 c"H4/,F
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A: UNION 运算符 &EXql']
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。 WaN0$66[:
B: EXCEPT 运算符 d<V+;">2
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 "a5?cX;
C: INTERSECT 运算符 7u!R 'D
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 (bH "x
注:使用运算词的几个查询结果行必须是一致的。 2j4VW0:
12、说明:使用外连接 f>waFu-
A、left outer join: {;Mcor3
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 .+ai
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SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 88pz<$
B:right outer join: /Rx%}~x/m
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。 t{!}^{
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C:full outer join: emw3cQ
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。 o,D>7|h
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二、提升 )`-9WCd&
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ECg/ge2
法一:select * into b from a where 1<>1 [ #A!B#`
法二:select top 0 * into b from a A<9ZX=DAjw
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) z:RwCd1\
insert into b(a, b, c) select d,e,f from b; M)I&^mm39
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) -Qiay/tlu
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 kd|@.
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. k2<VUeW5
4、说明:子查询(表名1:a 表名2:b) \ zhT1#O
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) H]UM2.
5、说明:显示文章、提交人和最后回复时间 Qgo0uuM
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b lx U}HM
6、说明:外连接查询(表名1:a 表名2:b) f Nm
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select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c sUfH1w)0
7、说明:在线视图查询(表名1:a ) k-Jj k3
select * from (SELECT a,b,c FROM a) T where t.a > 1; <|hvH
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 BA A)IQF
select * from table1 where time between time1 and time2 6;I&{9
select a,b,c, from table1 where a not between 数值1 and 数值2 UG&/0{j5XV
9、说明:in 的使用方法 S<88>|&n]
select * from table1 where a [not] in ('值1','值2','值4','值6') Nypa,_9}
10、说明:两张关联表,删除主表中已经在副表中没有的信息 f*1.Vg0`-
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) {G%`K,T
11、说明:四表联查问题: T"in
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 .....
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12、说明:日程安排提前五分钟提醒 -7'>Rw
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 {{SQL)yJ
13、说明:一条sql 语句搞定数据库分页 G0CmY43
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 ,U],Wu)
14、说明:前10条记录 PM7*@~.
select top 10 * form table1 where 范围 tE3!;
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.) < I8hy$+6
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) {/XzIOO;b
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 p!|Wp
(select a from tableA ) except (select a from tableB) except (select a from tableC) >Ah [uM
17、说明:随机取出10条数据 B6MMn.
select top 10 * from tablename order by newid() ysGK5kFz
18、说明:随机选择记录 asj^K|.z
select newid() O6Xu/X]
19、说明:删除重复记录 4}W*,&_
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) d01bt$8>
20、说明:列出数据库里所有的表名 4@/[aFH
select name from sysobjects where type='U' TN.mNl%
21、说明:列出表里的所有的 p8%x@%k
select name from syscolumns where id=object_id('TableName') ::9U5E;!
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。 +QtK
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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 ojT TYR{
显示结果: rzLpVpTaz
type vender pcs Y71io^td~j
电脑 A 1 \[B5j0vV,
电脑 A 1 &P&M6v+
光盘 B 2 ,m8l
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光盘 A 2 xs.>+(@|;
手机 B 3 jC@$D*"J
手机 C 3 &]ts*qCEL
23、说明:初始化表table1 deQ0)A 4g
TRUNCATE TABLE table1 !-U5d9!
24、说明:选择从10到15的记录 DNLqipUw
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 2%. A{!
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三、技巧 TlQ#0_as[
1、1=1,1=2的使用,在SQL语句组合时用的较多 Xb?P'nD
"where 1=1" 是表示选择全部 "where 1=2"全部不选, Cc$!TZq=
如: {tOu+zy
if @strWhere !='' R',Q)<
begin r[q-O&2&
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere QPg
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end rt_%_f>qd
else |XtN\9V.
begin :~~}|Eu
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' c/^}
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end }XX)U_x
我们可以直接写成 CDK0 $W n
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ?y>P
2、收缩数据库 vYKKv%LE
--重建索引 1}Tbp_
DBCC REINDEX +Hc[5WL
DBCC INDEXDEFRAG !)?n n3
--收缩数据和日志 !0zbWB9
DBCC SHRINKDB l"W9uS;\T
DBCC SHRINKFILE }/4 AT
3、压缩数据库 E<:XHjm
dbcc shrinkdatabase(dbname) ?k TVC
4、转移数据库给新用户以已存在用户权限 +j1s*}8
exec sp_change_users_login 'update_one','newname','oldname' VY<$~9a&1
go 58DkVQ 6
5、检查备份集 FWq+'GkSV
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' WJ<nc+/v:
6、修复数据库 M56^p,
ALTER DATABASE [dvbbs] SET SINGLE_USER 2RFYnDN
GO s+#gH@c
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK fFMGpibkM
GO 9s>q4_D
ALTER DATABASE [dvbbs] SET MULTI_USER WldlN?[j
GO }rj.N98
7、日志清除 B:\\aOEj
SET NOCOUNT ON Pv17wUB
DECLARE @LogicalFileName sysname, lG I1LUo
@MaxMinutes INT, Aq yR+
@NewSize INT IlVz 5#R
USE tablename -- 要操作的数据库名 !TA6- ]1
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 (+`pEDD{X
@MaxMinutes = 10, -- Limit on time allowed to wrap log. %YkJA:
@NewSize = 1 -- 你想设定的日志文件的大小(M) aHNR0L3$}{
-- Setup / initialize ]>tYU
DECLARE @OriginalSize int 5Ev9u),D+v
SELECT @OriginalSize = size ] JVs/
FROM sysfiles 4/;hA
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WHERE name = @LogicalFileName jVC`38|
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 5=WzKM
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 12`q9Io"
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 'W(+rTFf!
FROM sysfiles %PRG;kR
WHERE name = @LogicalFileName (OwAhjHE
CREATE TABLE DummyTrans ea kj>7\s
(DummyColumn char (8000) not null) )r3}9J
DECLARE @Counter INT, :hJHjh
@StartTime DATETIME, n+QUT
@TruncLog VARCHAR(255) Ebw1 %W KC
SELECT @StartTime = GETDATE(), cKJf0S:cx-
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' cXU8}>qY7
DBCC SHRINKFILE (@LogicalFileName, @NewSize) w#vSZbh
EXEC (@TruncLog) Zyt,D|eWj
-- Wrap the log if necessary. HY0q!.qog
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired hiq7e*Nsb
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) DDxbIkt
AND (@OriginalSize * 8 /1024) > @NewSize
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BEGIN -- Outer loop. YT'G#U1x~
SELECT @Counter = 0 a"SH_+T{
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) x)N$.7'9OJ
BEGIN -- update F0:|uC4
INSERT DummyTrans VALUES ('Fill Log') $\M<gW6
DELETE DummyTrans
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SELECT @Counter = @Counter + 1 qB6@OS
END #S)]`YW
EXEC (@TruncLog) sL" h
END @ol=gBU
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 2l]*><q|
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + t5t,(^ ;f
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' I,TJV)B
FROM sysfiles ,cZhkXd
WHERE name = @LogicalFileName l/1u>'
DROP TABLE DummyTrans GKT2x '(e
SET NOCOUNT OFF Fa<>2KkOr
8、说明:更改某个表 cq lA"Eof
exec sp_changeobjectowner 'tablename','dbo' G&=4@pLY5
9、存储更改全部表 ,)/gy)~#
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch (3cJ8o>&
@OldOwner as NVARCHAR(128), hgIqr^N9
@NewOwner as NVARCHAR(128) H'KCIqo
AS P 4Vi~zMX
DECLARE @Name as NVARCHAR(128) <7'`N\a
DECLARE @Owner as NVARCHAR(128) a%| I'r
DECLARE @OwnerName as NVARCHAR(128) FvYgp bEZ
DECLARE curObject CURSOR FOR URU,&gy=
select 'Name' = name, 0U|t@&q
'Owner' = user_name(uid) j/.$ (E
from sysobjects \ #<.&`8B
where user_name(uid)=@OldOwner EQe !&;
order by name "NEg]LB5
OPEN curObject 8T6LD
FETCH NEXT FROM curObject INTO @Name, @Owner ^*sDJ #
WHILE(@@FETCH_STATUS=0) 9
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BEGIN
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if @Owner=@OldOwner F.{{gpI
begin $HgBzZ7A2
set @OwnerName = @OldOwner + '.' + rtrim(@Name) x}\x3U
exec sp_changeobjectowner @OwnerName, @NewOwner O[}{$NXw
end zs/4tNXw
-- select @name,@NewOwner,@OldOwner `+DH@ce
FETCH NEXT FROM curObject INTO @Name, @Owner h?_Cv*0q
END K[wny0 (
close curObject eTg8I/)%B
deallocate curObject "/e_[_j
GO (LiS9|J!
10、SQL SERVER中直接循环写入数据 :ohGG ,`Dh
declare @i int a ?D]]0%
set @i=1 zT<fTFJ1
while @i<30 I=aoP}_
begin 6/-]
insert into test (userid) values(@i) *vy^=Yea
set @i=@i+1 {!RDb'Zp
end f3yH4r?;w
小记存储过程中经常用到的本周,本月,本年函数 F/pq9
Dateadd(wk,datediff(wk,0,getdate()),-1) /ILj}g'
Dateadd(wk,datediff(wk,0,getdate()),6) OlU')0Y
Dateadd(mm,datediff(mm,0,getdate()),0) ->Z9j(JU
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) 1Vf?Rw
Dateadd(yy,datediff(yy,0,getdate()),0) /80H.|8O
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 8^IV`P~2M
上面的SQL代码只是一个时间段 zM+4<k_dH]
Dateadd(wk,datediff(wk,0,getdate()),-1) LZ#=Ks
Dateadd(wk,datediff(wk,0,getdate()),6) pbCj
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就是表示本周时间段. { 6
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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: -VZn`6%s
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) DWv(|gO
而在存储过程中 Lql2ry$Wa
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) ^aG$9N<\
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) e
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