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。 ";
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一、基础 REJHh\:.77
1、说明:创建数据库 5GDg_9Bz
CREATE DATABASE database-name )Qh*@=$-
2、说明:删除数据库 FA}y"I'W
drop database dbname & DhdB0Hjf
3、说明:备份sql server ricL.[v9S
--- 创建 备份数据的 device +w8$-eFY
USE master 3|4<SMm
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' H}gp`YW:4
--- 开始 备份 LU+}iA)
BACKUP DATABASE pubs TO testBack Pdk#"H-j
4、说明:创建新表 "0J;H#Y"#
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) u0nIr9
根据已有的表创建新表: >YR2h/S
A:create table tab_new like tab_old (使用旧表创建新表) RhkTN'vO
B:create table tab_new as select col1,col2... from tab_old definition only 8+8L'Yv;
5、说明:删除新表 zEi\#Zg$
drop table tabname Hh*
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6、说明:增加一个列 Y-~MkB
Alter table tabname add column col type 3|bbJ6*.<
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。 hp}JKj@
7、说明:添加主键: Alter table tabname add primary key(col) #{@qC2!2/
说明:删除主键: Alter table tabname drop primary key(col) ,6SzW+L7
8、说明:创建索引:create [unique] index idxname on tabname(col....) )a<MW66
删除索引:drop index idxname b fI= =
注:索引是不可更改的,想更改必须删除重新建。 3)hQT-)
9、说明:创建视图:create view viewname as select statement ~#7uNH2
删除视图:drop view viewname JV?d/[u,
10、说明:几个简单的基本的sql语句 I?_WV_T&
选择:select * from table1 where 范围 %$67*pY'JH
插入:insert into table1(field1,field2) values(value1,value2) m+xub*/
删除:delete from table1 where 范围 _}tPtHPa/
更新:update table1 set field1=value1 where 范围 ,@\z{}~v
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! A+(+PfU
排序:select * from table1 order by field1,field2 [desc] ]rji]4s
总数:select count as totalcount from table1 .TNGiUzG
求和:select sum(field1) as sumvalue from table1 l YpoS
平均:select avg(field1) as avgvalue from table1
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最大:select max(field1) as maxvalue from table1 $Ww.^ym
最小:select min(field1) as minvalue from table1 ?0+N
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11、说明:几个高级查询运算词 rA}mp]
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A: UNION 运算符 *bUOd'vh
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 l[[^]__
B: EXCEPT 运算符 Gh352
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 tTT
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C: INTERSECT 运算符 (S2E'L L{
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 yw{r:fy
注:使用运算词的几个查询结果行必须是一致的。 MeV*]*
12、说明:使用外连接 Y$s4 *)%
A、left outer join: V=8npz
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。 5..YC=_20
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 L
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B:right outer join: 4RfBXVS
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。 >ByqM{?
C:full outer join: @WiTh'w0
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。 4gZ)9ya
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二、提升 4/OmgBo'
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) tlB-s;
法一:select * into b from a where 1<>1
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法二:select top 0 * into b from a Q{CRy-ha
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) $F NH:r<
insert into b(a, b, c) select d,e,f from b; N%%trlDXD
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) Lcf?VV}
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 U2CC#,b!(
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 8fktk?|
4、说明:子查询(表名1:a 表名2:b) q/ (h{cq
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) Y*IKPnPot2
5、说明:显示文章、提交人和最后回复时间 ,aIkiT
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b `G%h=rr^c
6、说明:外连接查询(表名1:a 表名2:b) %evtIU<h
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c kSEgq<i!
7、说明:在线视图查询(表名1:a ) 4p%^?L?
select * from (SELECT a,b,c FROM a) T where t.a > 1; ')/w+|F
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 C_yNSD
select * from table1 where time between time1 and time2 z[K)0@8 6
select a,b,c, from table1 where a not between 数值1 and 数值2 /IF?|71,m
9、说明:in 的使用方法 ^m
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select * from table1 where a [not] in ('值1','值2','值4','值6') Q$sC%P(y
10、说明:两张关联表,删除主表中已经在副表中没有的信息 q(A_k+NL
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) }$g"|;<ha
11、说明:四表联查问题: ;#mm_*L%@
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 ..... t<`d*M2w
12、说明:日程安排提前五分钟提醒 F{c8{?:
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 M^Tm{`O!
13、说明:一条sql 语句搞定数据库分页 ;aD?BD__Z
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 .{|SKhXk
14、说明:前10条记录 *\cU}qjk
select top 10 * form table1 where 范围 1
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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.) Cq'{%
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) HTMg{_r(%
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 7P]i|Q{
(select a from tableA ) except (select a from tableB) except (select a from tableC) ^Cvt^cI
17、说明:随机取出10条数据 G( BSe`f
select top 10 * from tablename order by newid() a
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18、说明:随机选择记录 Z4E6J'B8
select newid() Yq4nmr4
19、说明:删除重复记录 (:\L@j
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) h<8c{RuoZC
20、说明:列出数据库里所有的表名 f1sp6S0V\
select name from sysobjects where type='U' $4qM\3x0,
21、说明:列出表里的所有的 #2"'tHf4
select name from syscolumns where id=object_id('TableName') 9+/D\|"{
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 V]m}xZ'?^
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type s_^N=3Si
显示结果: %@|)&][hO
type vender pcs kUfb B#.5L
电脑 A 1 @Ae&1O;Zh
电脑 A 1 YY(_g|;?8
光盘 B 2 9c[bhGD?
光盘 A 2 53d`+an2
手机 B 3 Cl3L)
手机 C 3 d_ x
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23、说明:初始化表table1 MZxU)QW1
TRUNCATE TABLE table1 '=xO?2U-Z
24、说明:选择从10到15的记录 72_+ b
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Jd',v
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三、技巧 rBi6AM/
1、1=1,1=2的使用,在SQL语句组合时用的较多 K\zb+
"where 1=1" 是表示选择全部 "where 1=2"全部不选, }E[vW
如: dvz6
if @strWhere !='' 3\{\ al
begin IO]tO[P#
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere Qwve-[
end j5A>aj
else (44L8)I.D
begin XBB>"
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 3Bvz& `\
end K9yZG
我们可以直接写成 J<4_<.o(a
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ynZEJKo
2、收缩数据库 W~a|AU8]C
--重建索引 ~%eE%5!k
DBCC REINDEX hwQ|'^(@O
DBCC INDEXDEFRAG ]6s/y
--收缩数据和日志 :SWrx MT
DBCC SHRINKDB /-t!)_zvw
DBCC SHRINKFILE l*huKSX}
3、压缩数据库 y>#kT
dbcc shrinkdatabase(dbname) 7FD,TJs
4、转移数据库给新用户以已存在用户权限 m,J
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exec sp_change_users_login 'update_one','newname','oldname' :(.:bf
go 9a_UxF+6/
5、检查备份集 _a|g
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RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ^)a:DKL
6、修复数据库 H8B2{]HAt
ALTER DATABASE [dvbbs] SET SINGLE_USER ;uv$>Fauk
GO !VsdKG)
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK +nim47
GO Xwjm T
ALTER DATABASE [dvbbs] SET MULTI_USER 2X*n93AQi
GO b?VByJl
7、日志清除 7/_|/4&
SET NOCOUNT ON ;!lwB
DECLARE @LogicalFileName sysname, bv7xh*/
@MaxMinutes INT, '.8eLN
@NewSize INT L/,gD.h^
USE tablename -- 要操作的数据库名 (w\|yPBB
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 13)6p|6x
@MaxMinutes = 10, -- Limit on time allowed to wrap log. [dUAb
@NewSize = 1 -- 你想设定的日志文件的大小(M) -o~n06p
-- Setup / initialize J><hrZ
DECLARE @OriginalSize int x]?V*Jz
SELECT @OriginalSize = size <eP,/H
FROM sysfiles Uovna:"
WHERE name = @LogicalFileName 1zw,;m n
SELECT 'Original Size of ' + db_name() + ' LOG is ' + tFX<"cAvK
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + #3eI4KJ4+l
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' E>gLUMG$
FROM sysfiles A7&/3C6{H
WHERE name = @LogicalFileName p!)tA
CREATE TABLE DummyTrans W$&*i1<a+
(DummyColumn char (8000) not null) Ag*?>I
DECLARE @Counter INT, ?I:_FT
@StartTime DATETIME, Ey%[t
@TruncLog VARCHAR(255) .sOZ "=tW
SELECT @StartTime = GETDATE(), m=v.<+>
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' c&aqN\'4"
DBCC SHRINKFILE (@LogicalFileName, @NewSize) g
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EXEC (@TruncLog) G`&P|xYg
-- Wrap the log if necessary. mA_EvzXk\
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired (n_.bSI
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) $uUyp8F
AND (@OriginalSize * 8 /1024) > @NewSize 5dG+>7Iy}
BEGIN -- Outer loop. 5|t-CY{?b
SELECT @Counter = 0 $G9E=wn
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) d{) =E8wE
BEGIN -- update T+rym8.p
INSERT DummyTrans VALUES ('Fill Log') wV{j CQ
DELETE DummyTrans |u$*'EsP
SELECT @Counter = @Counter + 1 w)1SZ}
END WE_'u+!B
EXEC (@TruncLog) sSD&'K=lq
END yd'cLZd<}
SELECT 'Final Size of ' + db_name() + ' LOG is ' + B#.xs>{N
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + M?hPlo"_
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' K`ygW|?gt
FROM sysfiles LWSy"Cs*
WHERE name = @LogicalFileName {{[@ X
DROP TABLE DummyTrans z|Xt'?9&n
SET NOCOUNT OFF Z0D&ayzkh^
8、说明:更改某个表 ) te_ <W
exec sp_changeobjectowner 'tablename','dbo' 0}'/p N>
9、存储更改全部表 !U(KQ:j
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch K|6}g7&X
@OldOwner as NVARCHAR(128), a9_2b}t
@NewOwner as NVARCHAR(128) e8egxm
AS bNtOqhi
DECLARE @Name as NVARCHAR(128) u:J4Az^!
DECLARE @Owner as NVARCHAR(128) 6W7,EIf
DECLARE @OwnerName as NVARCHAR(128) : 0Y.${h
DECLARE curObject CURSOR FOR d(9Sk Xr
select 'Name' = name, 'd;aAG
'Owner' = user_name(uid) ;A*sub
from sysobjects .>PwbZ
where user_name(uid)=@OldOwner jv1p'qs4
order by name K@!hrye
OPEN curObject Z/v )^VR
FETCH NEXT FROM curObject INTO @Name, @Owner B>z^W+Unyn
WHILE(@@FETCH_STATUS=0) C:bA:O
BEGIN -xJ\/"A
if @Owner=@OldOwner J4iu8_eH!D
begin <Nc9F['
set @OwnerName = @OldOwner + '.' + rtrim(@Name) *laFG<;
exec sp_changeobjectowner @OwnerName, @NewOwner FT}^Fi7
end %$Q!'+YW
-- select @name,@NewOwner,@OldOwner 0TICv2l!
FETCH NEXT FROM curObject INTO @Name, @Owner VeQ [A?pER
END U~c9PqjZ
close curObject x}d5Y
deallocate curObject $[J\sokpY
GO je>gT`8
10、SQL SERVER中直接循环写入数据 @wP.Rd
declare @i int _n4`mL8>kH
set @i=1 c\tw#;\9
while @i<30 Ls.g\Gl3
begin BCd0X. m(
insert into test (userid) values(@i) V2tA!II-s
set @i=@i+1 p!?7;
end oW(8bd)
小记存储过程中经常用到的本周,本月,本年函数 [`KQ\4u
Dateadd(wk,datediff(wk,0,getdate()),-1) tEibxE
Dateadd(wk,datediff(wk,0,getdate()),6) \S~<C[P
Dateadd(mm,datediff(mm,0,getdate()),0) n
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