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。 qtQ:7WO
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一、基础 EUS]Se2
1、说明:创建数据库 Y9ce"*b
CREATE DATABASE database-name SF=|++b1f
2、说明:删除数据库 Y6DiISl
drop database dbname 9)hC,)5
3、说明:备份sql server *
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--- 创建 备份数据的 device LVtQ^ 5>8
USE master 3VBV_/i;
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' H#`?toS
--- 开始 备份 htSk2N/
BACKUP DATABASE pubs TO testBack #_|^C(]!
4、说明:创建新表 k<hO9;#qpL
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) F5q1VEe
根据已有的表创建新表: OHvzK8
A:create table tab_new like tab_old (使用旧表创建新表) ?0&>?-?
B:create table tab_new as select col1,col2... from tab_old definition only | N,nt@~
5、说明:删除新表 >c>ar>4xF
drop table tabname w%H#>k
6、说明:增加一个列 =gyK*F(RK
Alter table tabname add column col type 5h7DVr!
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。 bu5)~|?{t
7、说明:添加主键: Alter table tabname add primary key(col) #7"5Y_0-
说明:删除主键: Alter table tabname drop primary key(col) ] CE2/6Ph
8、说明:创建索引:create [unique] index idxname on tabname(col....) mW9b~G3k
删除索引:drop index idxname
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注:索引是不可更改的,想更改必须删除重新建。 ^Wz{su2
9、说明:创建视图:create view viewname as select statement yYtki
删除视图:drop view viewname EwZt/r
10、说明:几个简单的基本的sql语句 ;9sVWJJCw
选择:select * from table1 where 范围 )pH{b]t
插入:insert into table1(field1,field2) values(value1,value2) >n\Q[W
删除:delete from table1 where 范围 7U0):11X#
更新:update table1 set field1=value1 where 范围 u)MA#p {
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! .lS6KBf@
排序:select * from table1 order by field1,field2 [desc] 0zNS;wvv&
总数:select count as totalcount from table1 4Lb<#e13R?
求和:select sum(field1) as sumvalue from table1 NFPkK?+
平均:select avg(field1) as avgvalue from table1 HWZ*Htr
最大:select max(field1) as maxvalue from table1 {IwYoR aXa
最小:select min(field1) as minvalue from table1 m&8_i`%<
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11、说明:几个高级查询运算词 Vi-@z;k
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A: UNION 运算符 qm_E/B
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。 <O&s 'A[
B: EXCEPT 运算符 T^SOq:m&
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。 gE(03SX
C: INTERSECT 运算符 K)Ka"H
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。 %LmB`DqZ
注:使用运算词的几个查询结果行必须是一致的。 AkC\CdmA
12、说明:使用外连接 pDfF'jt9
A、left outer join: 4TV9t"Dk+c
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。 =T6\kz9)`
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 A;PV,2|X
B:right outer join: >cLZP#^\2E
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。 Yuck]?#0
C:full outer join: 7T78S&g
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。 ^ 2tCDm5
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二、提升 ;pq4El_
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 8a1{x(\z.
法一:select * into b from a where 1<>1 1' s^W
法二:select top 0 * into b from a i^Q^F
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) cl5 :|)
insert into b(a, b, c) select d,e,f from b; <L0_<T
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) iLei-\w6y
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 vzPrG%Uu7g
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. %/p5C
4、说明:子查询(表名1:a 表名2:b) 1+zax*gO-
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) )JON&~C
5、说明:显示文章、提交人和最后回复时间 7="V7
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b .v'8G)6g
6、说明:外连接查询(表名1:a 表名2:b) 0jMrL\>C
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c K+H82$
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7、说明:在线视图查询(表名1:a ) `. Z".
select * from (SELECT a,b,c FROM a) T where t.a > 1; U6"50G~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 _1QNO#X
select * from table1 where time between time1 and time2 >FO=ioNY
select a,b,c, from table1 where a not between 数值1 and 数值2 ygG9ht
9、说明:in 的使用方法 ektFk"W3A\
select * from table1 where a [not] in ('值1','值2','值4','值6') r\?*?sL
10、说明:两张关联表,删除主表中已经在副表中没有的信息 EhoR.
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) + `xp+Q
11、说明:四表联查问题: DzMk eX
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 ..... Zf! 7pM
12、说明:日程安排提前五分钟提醒 H>?@nYP
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 5sRNqTIr
13、说明:一条sql 语句搞定数据库分页 ?/D#ql7
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 ,KWeW^z'7
14、说明:前10条记录 [;}c@
select top 10 * form table1 where 范围 ?Eed#pb_
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.)
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select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) dx#N)?
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 $U1'n@/J
(select a from tableA ) except (select a from tableB) except (select a from tableC) ^;e`ZtcI
17、说明:随机取出10条数据 /on p<u
select top 10 * from tablename order by newid() Fwtwf{9I
18、说明:随机选择记录 ~Km8-b(&
select newid() $vd._j&
19、说明:删除重复记录 .x&>H
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) *niQ*A
20、说明:列出数据库里所有的表名 Fc
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select name from sysobjects where type='U' 1RLSeT
21、说明:列出表里的所有的 1JY4E2Q
select name from syscolumns where id=object_id('TableName') @%K 8oYK
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 m`|+_{4[n
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type j56Y,Tm
显示结果: #&^+hx|
type vender pcs qH$p]+Rk 5
电脑 A 1 1Pbp=R/7ar
电脑 A 1 .(krB%N
光盘 B 2 <qu\q \
光盘 A 2 UqH7e c
手机 B 3 G{<wXxq%
手机 C 3 $%<gp@Gz
23、说明:初始化表table1 H!N,PI?rn
TRUNCATE TABLE table1 afjC~}
24、说明:选择从10到15的记录 mdwY48b
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc '5IJ;4k
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三、技巧 B{Rig5Sc
1、1=1,1=2的使用,在SQL语句组合时用的较多 c?|/c9f
"where 1=1" 是表示选择全部 "where 1=2"全部不选, @<P[z[
如: $JOIK9+3z#
if @strWhere !='' @-wAR=k7
begin cI H`,bR
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere MFVFr "
end aLr^uce]
else i
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begin 6*%lnd+_
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' ezL*YM8?@
end 5<61NnZ
我们可以直接写成 _=rXaTp
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere d 1z
2、收缩数据库 Ofn:<d
--重建索引 >DDQ7
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DBCC REINDEX fK[9<"PC0
DBCC INDEXDEFRAG kG{(Qi
--收缩数据和日志 kb>9;-%^JK
DBCC SHRINKDB *op7:o_
DBCC SHRINKFILE v / a/
3、压缩数据库 |Q$C%7
dbcc shrinkdatabase(dbname) )]>9\(
4、转移数据库给新用户以已存在用户权限 {^~{X$YI
exec sp_change_users_login 'update_one','newname','oldname' BD#4=u
go "l!"gc87
5、检查备份集 pz(clTOD:
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ?C_%"!GR
6、修复数据库 6rk/74gI,a
ALTER DATABASE [dvbbs] SET SINGLE_USER KxvT}"k
GO +_+_`q>]
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ym:JtI69
GO 4;_.|!LN
ALTER DATABASE [dvbbs] SET MULTI_USER Q)v8hNyUmA
GO sQR;!-j
7、日志清除 ]O 2_&cs
SET NOCOUNT ON T_r[#j
DECLARE @LogicalFileName sysname, Q.nEY6B_
@MaxMinutes INT, ?Hy++
@NewSize INT B]jh$@
USE tablename -- 要操作的数据库名 i
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SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ,L`qV
@MaxMinutes = 10, -- Limit on time allowed to wrap log. L&eO?I=,
@NewSize = 1 -- 你想设定的日志文件的大小(M) n^'{{@&(v
-- Setup / initialize NKd):>d%
DECLARE @OriginalSize int v5&WW?IBQ
SELECT @OriginalSize = size eudPp"Km
FROM sysfiles 9t= erhUr
WHERE name = @LogicalFileName n32?GRp
SELECT 'Original Size of ' + db_name() + ' LOG is ' + mv5!fp_*7
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 3b|.L
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' D 4@=+
FROM sysfiles %$b
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WHERE name = @LogicalFileName D0uf=BbS
CREATE TABLE DummyTrans &:Q""e!
(DummyColumn char (8000) not null) 1cUC>_%?
DECLARE @Counter INT, |%$d/<<PZ
@StartTime DATETIME, l*h6JgU
@TruncLog VARCHAR(255) A+?n=IHh
SELECT @StartTime = GETDATE(), ]t<%v_K
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' /+'@}u
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) sH6srwI
EXEC (@TruncLog) e7<~[>g)
-- Wrap the log if necessary. A=BpB}b
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired T%Z `:mf
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) jAF
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AND (@OriginalSize * 8 /1024) > @NewSize 3n
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BEGIN -- Outer loop. =\`9 \Gd
SELECT @Counter = 0 tr):n@
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) Dt8eVWkN ~
BEGIN -- update 5o&L|7]
INSERT DummyTrans VALUES ('Fill Log') S&|$F2M
DELETE DummyTrans IN_GL18^MV
SELECT @Counter = @Counter + 1 #E>f.:)
END |i1z47jN6P
EXEC (@TruncLog) UUX
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END s*rtm
SELECT 'Final Size of ' + db_name() + ' LOG is ' + Rb#?c+&#
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 5FzG_ w
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' V$@@!q
FROM sysfiles #~(@Ka.eA0
WHERE name = @LogicalFileName )5&Wt@7Kj`
DROP TABLE DummyTrans ZSxKk6n}J
SET NOCOUNT OFF K{HdqmxL.I
8、说明:更改某个表 =$fxK
exec sp_changeobjectowner 'tablename','dbo' Jg^tr>I~
9、存储更改全部表 aRfkJPPa[
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch nLYyS#
@OldOwner as NVARCHAR(128), h%#@Xd>.
@NewOwner as NVARCHAR(128) 60-LpGhvy
AS vw3%u+Z&
DECLARE @Name as NVARCHAR(128) a ipvG
DECLARE @Owner as NVARCHAR(128) fyT! /
DECLARE @OwnerName as NVARCHAR(128) ](^VEm}w;
DECLARE curObject CURSOR FOR D`iWf3a.
select 'Name' = name, k?1cxY s
'Owner' = user_name(uid) +STT(b Mn
from sysobjects <[b\V+M
where user_name(uid)=@OldOwner :'#BU:
order by name ,1QU
OPEN curObject ;p1%KmK3
FETCH NEXT FROM curObject INTO @Name, @Owner BYP,}yzA
WHILE(@@FETCH_STATUS=0) 5Gg`+o
BEGIN to+jQ9q8
if @Owner=@OldOwner s|YY i~
begin .GLotc
set @OwnerName = @OldOwner + '.' + rtrim(@Name) v='7.A
exec sp_changeobjectowner @OwnerName, @NewOwner %5jxq9:K
end ;<MHDmD
-- select @name,@NewOwner,@OldOwner dEns|r
FETCH NEXT FROM curObject INTO @Name, @Owner ^25$=0
END QfRt3\^`
close curObject H#G'q_uHH
deallocate curObject 9
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GO {H"xC~.
10、SQL SERVER中直接循环写入数据 J1&G1\G|s=
declare @i int TC"mP!1
set @i=1 <