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。 oDTt+b
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一、基础 {Lb NKjn
1、说明:创建数据库 gAC}
CREATE DATABASE database-name ?C//UN;
2、说明:删除数据库 P49lE
drop database dbname .t4IR
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3、说明:备份sql server aG8}R~wH&
--- 创建 备份数据的 device R:x4j#(
USE master |[}YM%e
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' `#A&v
--- 开始 备份 RO=[Rr!
BACKUP DATABASE pubs TO testBack b-ULoV
4、说明:创建新表 kWc%u-_
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) aAF:nyV~~0
根据已有的表创建新表: YQ
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A:create table tab_new like tab_old (使用旧表创建新表) z9U<Z^4z+
B:create table tab_new as select col1,col2... from tab_old definition only AtYe\_9$C
5、说明:删除新表 Ku*@4#<L6h
drop table tabname dY68wW>d|
6、说明:增加一个列 rJ]iJ0[I
Alter table tabname add column col type W*e6F?G
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。 ^q_0(Vf
7、说明:添加主键: Alter table tabname add primary key(col) N?U;G*G
说明:删除主键: Alter table tabname drop primary key(col) }k.-xaj
8、说明:创建索引:create [unique] index idxname on tabname(col....) 2)h
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删除索引:drop index idxname $)vljM<<
注:索引是不可更改的,想更改必须删除重新建。 rXuhd [!(P
9、说明:创建视图:create view viewname as select statement VZ'[\3J
删除视图:drop view viewname *4Y1((1k
10、说明:几个简单的基本的sql语句 di>"\On-
选择:select * from table1 where 范围 f{FW7T}O2
插入:insert into table1(field1,field2) values(value1,value2) {=PO`1H
删除:delete from table1 where 范围 wAkpk&R
更新:update table1 set field1=value1 where 范围
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查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! 8]]uk=P
排序:select * from table1 order by field1,field2 [desc] q|b#=Af]g
总数:select count as totalcount from table1 IkFrzw p
求和:select sum(field1) as sumvalue from table1 >K1)XP
平均:select avg(field1) as avgvalue from table1 a&6 3[p.<}
最大:select max(field1) as maxvalue from table1 TDs=VTd@Z
最小:select min(field1) as minvalue from table1 /jaTH_Q),:
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11、说明:几个高级查询运算词 x5YW6R.<t
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A: UNION 运算符 [5e}A&
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 Hgu$)yhlj
B: EXCEPT 运算符 z6]dF"N
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。 B\r2M`N5
C: INTERSECT 运算符 ^.p({6H
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。 >8D!K0?E
注:使用运算词的几个查询结果行必须是一致的。 N9tH0
12、说明:使用外连接 d&4ve Lu
A、left outer join: H<#M)8
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。 =,$*-<p=3
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ,dhJ\cQ~
B:right outer join: -KhNsUQk
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 K'%2 'd
C:full outer join: H?*EQK`7?0
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 U(P^-J<n1
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二、提升 1)pwR3(^Fz
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ~~a,Fyko2
法一:select * into b from a where 1<>1 /2l&D~d"
法二:select top 0 * into b from a 1DgRV7
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) U$v|c%6
insert into b(a, b, c) select d,e,f from b; v_mk{
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) ;$,=VB:'
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 nF>41 K
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. "BT*9N=|
4、说明:子查询(表名1:a 表名2:b) 6!zBLIYFI
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) a?jUm.
5、说明:显示文章、提交人和最后回复时间 J!Er%QUR
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b w^z5O6
6、说明:外连接查询(表名1:a 表名2:b) SQ8xfD*
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c \~m\pf?
7、说明:在线视图查询(表名1:a ) ve($l"T
select * from (SELECT a,b,c FROM a) T where t.a > 1; F]e`-;
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 (StX1g'
select * from table1 where time between time1 and time2 ?+av9;Kg
select a,b,c, from table1 where a not between 数值1 and 数值2 X-LCIT|1
9、说明:in 的使用方法 Q2yD4>qy
select * from table1 where a [not] in ('值1','值2','值4','值6') zU7co.G
10、说明:两张关联表,删除主表中已经在副表中没有的信息 ~MWI-oK
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) j5m KJC
11、说明:四表联查问题: oCfO:7
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 ..... p3r("\Za,
12、说明:日程安排提前五分钟提醒 Y`F) UwKK
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 B@cC'F#G
13、说明:一条sql 语句搞定数据库分页 }`KK
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\*]cw
14、说明:前10条记录 ezimQ
select top 10 * form table1 where 范围
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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.) wcH,!;3z+
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) /tm2b<G
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 4>^LEp
(select a from tableA ) except (select a from tableB) except (select a from tableC) n*A?>NV
17、说明:随机取出10条数据 m`i_O0T
select top 10 * from tablename order by newid() r{>Q{$Q
18、说明:随机选择记录 RW~!)^
select newid() Z(j"\d!y
19、说明:删除重复记录 mR["xDHD
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) Ri>4:V3K
20、说明:列出数据库里所有的表名 %xt;&HE
select name from sysobjects where type='U' %k%%3L,
21、说明:列出表里的所有的 [Ef6@
select name from syscolumns where id=object_id('TableName') >|X )
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。 b?{MXJ|
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 X)e#=w!fi3
显示结果: n6AA%? 5
type vender pcs ZnKjU ]m
电脑 A 1 (+yH
电脑 A 1 k5M5bH',
光盘 B 2 = N&5]Z
光盘 A 2 {FQ@eeU
手机 B 3 pfBe24q
手机 C 3 azz=,^U#
23、说明:初始化表table1 <%o9*)F
TRUNCATE TABLE table1 rJZR8bo
24、说明:选择从10到15的记录 arIEd VfNa
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc l-Be5?|{_
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三、技巧 @)\4 $#+-
1、1=1,1=2的使用,在SQL语句组合时用的较多 Rh}}8 sv
"where 1=1" 是表示选择全部 "where 1=2"全部不选, #x qiGK
如: 5U-SIG*
if @strWhere !='' =t^jlb
begin #M%K82"
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere G9^xv
end bwM?DY
else qnCjNN
begin 3eg6 CdT
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' @R-11wP)M
end 2x>7>;>
我们可以直接写成 dz?On\66
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ZIKSHC9
2、收缩数据库 h@E7wp1'~
--重建索引 0kSM$D_
DBCC REINDEX Xp] jF^5
DBCC INDEXDEFRAG )=#e*1!b
--收缩数据和日志 ta6>St7.
DBCC SHRINKDB lb$_$+@Vr
DBCC SHRINKFILE RIQ-mpg~(k
3、压缩数据库 I_5/e>9
dbcc shrinkdatabase(dbname) s`ZP2"`f
4、转移数据库给新用户以已存在用户权限 RC}m]!Uz
exec sp_change_users_login 'update_one','newname','oldname' |h}4J
go ,-hbwd~M
5、检查备份集 ,]:Gn5~
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ufCpX>lNF
6、修复数据库 D2g/P8.<A
ALTER DATABASE [dvbbs] SET SINGLE_USER IMr#5
GO |.,]0CRg
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 6I: 6+n
GO _Dd>e=v
ALTER DATABASE [dvbbs] SET MULTI_USER 5x%Blkx
GO jz`3xFy *]
7、日志清除 PW|=IPS
SET NOCOUNT ON "w$,`M?2
DECLARE @LogicalFileName sysname, pU9.#O
@MaxMinutes INT, Gbjh|j=
@NewSize INT 0PqI^|!
USE tablename -- 要操作的数据库名 Q?;Tc.O"/
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 xL1Li]fM!'
@MaxMinutes = 10, -- Limit on time allowed to wrap log. DI8<0.L
@NewSize = 1 -- 你想设定的日志文件的大小(M) Xp_m=QQsm
-- Setup / initialize a_+?#m
DECLARE @OriginalSize int i^e8.zgywF
SELECT @OriginalSize = size r88De=*
FROM sysfiles "!D y[J
WHERE name = @LogicalFileName ax>j3HKi
SELECT 'Original Size of ' + db_name() + ' LOG is ' + $,2T~1tE
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + jQzl!f1c3
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' mE`qA*=?
FROM sysfiles X3a 9-
WHERE name = @LogicalFileName |4g0@}nr+W
CREATE TABLE DummyTrans /zt M'
(DummyColumn char (8000) not null) JLnv O
DECLARE @Counter INT, R2n
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@StartTime DATETIME, :^WF%X
@TruncLog VARCHAR(255) ;<N:! $p
SELECT @StartTime = GETDATE(), Jn^b}bk t
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' cLl~4jL
DBCC SHRINKFILE (@LogicalFileName, @NewSize) %2T
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EXEC (@TruncLog) GE(~d '
-- Wrap the log if necessary. >9rZVNMU
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired @U18Dj[
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) YO .+-(
AND (@OriginalSize * 8 /1024) > @NewSize w^ut,`yWR
BEGIN -- Outer loop. e~'lWJD
SELECT @Counter = 0 *9"x0bth
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ~<f[7dBv
BEGIN -- update gr*CN<
INSERT DummyTrans VALUES ('Fill Log') VJqk0w+
DELETE DummyTrans =K18| Q0m
SELECT @Counter = @Counter + 1 GM0Q@`d
END !*}UP|8
EXEC (@TruncLog) RC/ 3\'
END N=BG0t$
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 8 s$6R|ti
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + GeTk/tU
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ##=$$1Ki
FROM sysfiles uy's eJ
WHERE name = @LogicalFileName 7bzm5w@v
DROP TABLE DummyTrans \"oZ\_
SET NOCOUNT OFF <'~m1l#2
8、说明:更改某个表 ZrTB%
exec sp_changeobjectowner 'tablename','dbo' %`yfi+e
9、存储更改全部表 C~B ]@xxK)
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Q+=pP'cV
@OldOwner as NVARCHAR(128), &
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@NewOwner as NVARCHAR(128) );h(D!D,
AS uqC#h,~
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DECLARE @Name as NVARCHAR(128) 3&+dyhL'w
DECLARE @Owner as NVARCHAR(128) kun/KY
DECLARE @OwnerName as NVARCHAR(128) 0cq@lT6
DECLARE curObject CURSOR FOR E7fQ9]
select 'Name' = name, P>C'?'Q7
'Owner' = user_name(uid) ki9&AFs2X
from sysobjects b$,Hlh,^
where user_name(uid)=@OldOwner ^
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order by name </{Zb.
OPEN curObject . ,^WCyvq
FETCH NEXT FROM curObject INTO @Name, @Owner TU0-L35P1
WHILE(@@FETCH_STATUS=0) iPTQqx-m$7
BEGIN Q?k*3A
if @Owner=@OldOwner V:kRr cX
begin ma~#E$i&
set @OwnerName = @OldOwner + '.' + rtrim(@Name) |#@7$#j
exec sp_changeobjectowner @OwnerName, @NewOwner WR)=VE
end v_!6S|
-- select @name,@NewOwner,@OldOwner N&NBn(
FETCH NEXT FROM curObject INTO @Name, @Owner ,x8;| o5
END [s>3xWZ+a
close curObject il5C9ql$
deallocate curObject ]nhh|q9r{
GO &u.{]Yjx
10、SQL SERVER中直接循环写入数据 by@KdQow
declare @i int 8}B
set @i=1 }csA|cC
while @i<30 0>sa{Z
begin <