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。 Z;njSw%:
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一、基础 EV7lgKM^
1、说明:创建数据库 &xp]9$
CREATE DATABASE database-name l=x(
2、说明:删除数据库 /!qP=ngw9
drop database dbname 2jxIr-a1G
3、说明:备份sql server }(,{^".[}
--- 创建 备份数据的 device h\Q@zR*0a
USE master e3?z^AUXm
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' wuM'M<J@
--- 开始 备份 RE4WD9n
BACKUP DATABASE pubs TO testBack Ty#sY'%
4、说明:创建新表 WdB\n/BWB
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) Ey=}bBx
根据已有的表创建新表: X~SNkM
A:create table tab_new like tab_old (使用旧表创建新表) "oyBF CW
B:create table tab_new as select col1,col2... from tab_old definition only \xcf<y3_
5、说明:删除新表 KP7 {
drop table tabname wuW{2+)B
6、说明:增加一个列 D4uAwmc
Alter table tabname add column col type V^rL
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。 5=%KK3
7、说明:添加主键: Alter table tabname add primary key(col) iio-RT?!
说明:删除主键: Alter table tabname drop primary key(col) Kmw #Q`
8、说明:创建索引:create [unique] index idxname on tabname(col....) .Lu3LVS
删除索引:drop index idxname *z.rOY=
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注:索引是不可更改的,想更改必须删除重新建。 }D.\2x(J
9、说明:创建视图:create view viewname as select statement X5)(,036
删除视图:drop view viewname Kr;=4xg=
10、说明:几个简单的基本的sql语句 G*jq5_6
选择:select * from table1 where 范围 +L@\/=;G
插入:insert into table1(field1,field2) values(value1,value2) L27WD m^)
删除:delete from table1 where 范围 M?GkHJ %!
更新:update table1 set field1=value1 where 范围 ia3!&rZ
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! rm-;Z<
排序:select * from table1 order by field1,field2 [desc] ).A9>^6?{
总数:select count as totalcount from table1 @th94tk,
求和:select sum(field1) as sumvalue from table1 :8HVq*itS
平均:select avg(field1) as avgvalue from table1 {m@tt{%
最大:select max(field1) as maxvalue from table1 o8v,178
最小:select min(field1) as minvalue from table1 |~PaCw8-ge
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11、说明:几个高级查询运算词 pf%;*
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A: UNION 运算符 yqVoedN
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。 *M_^I)*L
B: EXCEPT 运算符 <q>d@Foi
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。 )[|_q,
C: INTERSECT 运算符 cG%X}ZV5
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。 rs( e
注:使用运算词的几个查询结果行必须是一致的。 fre5{=@
12、说明:使用外连接 pLys%1hg
A、left outer join: ) xKW
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。 +r9neS.l
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 "z;R"sv\
B:right outer join: ~"<^4h
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。 |lZp5MOc
C:full outer join: ~sPXkLqK
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。 1[$zdv{A
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二、提升 p\9}}t7n
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) w7&.Uqjf
法一:select * into b from a where 1<>1 WglpWp)
法二:select top 0 * into b from a &%;n9K
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) o*ucw3s>
insert into b(a, b, c) select d,e,f from b; 4nQ5zwiV
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) M ?AX:0
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 8FZC0j.^DH
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. s@{~8cHgU
4、说明:子查询(表名1:a 表名2:b) ^E:-Uy
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) }`%ks
5、说明:显示文章、提交人和最后回复时间 ;R
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select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b CC;^J-h/
6、说明:外连接查询(表名1:a 表名2:b) bN03}&I
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c D.|r
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7、说明:在线视图查询(表名1:a ) !pkIaCxs
select * from (SELECT a,b,c FROM a) T where t.a > 1; z
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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 5Pxx)F9]
select * from table1 where time between time1 and time2 W&&|T;P<J
select a,b,c, from table1 where a not between 数值1 and 数值2 8lGM>(:o
9、说明:in 的使用方法 ,<)D3K<
select * from table1 where a [not] in ('值1','值2','值4','值6') +6
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10、说明:两张关联表,删除主表中已经在副表中没有的信息 mfS}+_ C
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) KfYU.Q
11、说明:四表联查问题: CV_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 ..... OK8Ho"
12、说明:日程安排提前五分钟提醒 cofdDHXfQI
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 NO@`*:.^Y
13、说明:一条sql 语句搞定数据库分页 tf|;'Nc6
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 t|hc`|
14、说明:前10条记录 Zq<j}vVJ
select top 10 * form table1 where 范围 0a^bAEP
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.) |WEl5 bNc3
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) X!mJUDzh]
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 u[Si=)`VPk
(select a from tableA ) except (select a from tableB) except (select a from tableC) 5]upfC6
17、说明:随机取出10条数据 ~zG)<S"q
select top 10 * from tablename order by newid() hayJgkZ'
18、说明:随机选择记录 }!R*Q`m
select newid() -2 >s#/%
19、说明:删除重复记录 o 9/,@Ri\5
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) c5b}q@nH
20、说明:列出数据库里所有的表名 ,\c V,$
select name from sysobjects where type='U' i$Kx@,O8t
21、说明:列出表里的所有的 CCol>:8{P
select name from syscolumns where id=object_id('TableName') JbS[(+o
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。 O9/)_:Wdh
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 .{*l,
显示结果: -gS9I^
type vender pcs *hJWuMfY,
电脑 A 1 #ojuSS3
电脑 A 1 ,aGIq. *v
光盘 B 2 *78c2`)[
光盘 A 2 m-ibS:
手机 B 3 }^$1<GT
手机 C 3 O(!;7v}
23、说明:初始化表table1 #+V4<o
TRUNCATE TABLE table1 cL~WDW/
24、说明:选择从10到15的记录 -,T!/E
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc V,0$mBYa
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三、技巧 /4 OmnE;
1、1=1,1=2的使用,在SQL语句组合时用的较多 "~._G5i.
"where 1=1" 是表示选择全部 "where 1=2"全部不选, {i?G:K
如: ge.>#1f}
if @strWhere !='' KK2YT/K$SG
begin !4=_l6kg~+
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere -m=A1~|7
end yiI
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else {wj%WSQj/y
begin L6fbR-&Lt
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' strM3j##x
end 2,`X@N`\
我们可以直接写成 $fT5Vc]B4
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere W;2J~V!c
2、收缩数据库 3nc\6v%
--重建索引 O6)Po
DBCC REINDEX .ml\z5
DBCC INDEXDEFRAG K sE$^`
--收缩数据和日志 ?kQY ^pU
DBCC SHRINKDB v
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DBCC SHRINKFILE gh\u@#$8
3、压缩数据库 ,=4,eCS
dbcc shrinkdatabase(dbname) Qg~w 3~
4、转移数据库给新用户以已存在用户权限 s(5hFuyg
exec sp_change_users_login 'update_one','newname','oldname' ;CF:cH*
go *pSnEWwE
5、检查备份集 g3&nxZ
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' :q*w_*w
6、修复数据库 R6oD
ALTER DATABASE [dvbbs] SET SINGLE_USER o5DT1>h
GO jOrfI-&.G
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK Fpn*]x
GO QOYMT( j
ALTER DATABASE [dvbbs] SET MULTI_USER N{Z+
GO 4:NMZ `~
7、日志清除 ^Cp2#d*
SET NOCOUNT ON N\B&|;-V
DECLARE @LogicalFileName sysname, h
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@MaxMinutes INT, #)xlBq4cZ
@NewSize INT 8tQL$CbO
USE tablename -- 要操作的数据库名 <nD@4J-A0
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 [~
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@MaxMinutes = 10, -- Limit on time allowed to wrap log. :??W3ROn
@NewSize = 1 -- 你想设定的日志文件的大小(M) b~:)d>s8wY
-- Setup / initialize KB|mtsi
DECLARE @OriginalSize int %A'mXatk
SELECT @OriginalSize = size {.AN4
FROM sysfiles ;hO6 p
WHERE name = @LogicalFileName _.V5-iN
SELECT 'Original Size of ' + db_name() + ' LOG is ' + ~5%3]
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + JZ`h+fAt
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' g=Xy{Vm
FROM sysfiles UCfouQ Cj
WHERE name = @LogicalFileName W}TP(~x'N
CREATE TABLE DummyTrans (?R!y -
(DummyColumn char (8000) not null) M(K7xx+G
DECLARE @Counter INT, P658
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@StartTime DATETIME, -sKtT 9o
@TruncLog VARCHAR(255) *nJ,|T
SELECT @StartTime = GETDATE(), ou~$XZ7oi
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' >4Tk#+%Jj
DBCC SHRINKFILE (@LogicalFileName, @NewSize) DGb1_2ZQ
EXEC (@TruncLog) tJ K58m$
-- Wrap the log if necessary. lW-h
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WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired I8)D
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) { m~)~/z?
AND (@OriginalSize * 8 /1024) > @NewSize #2ta8m),
BEGIN -- Outer loop. MooH`2Fd
SELECT @Counter = 0 ;#9?3Os
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) fv+ET:T%
BEGIN -- update u%:`r*r
INSERT DummyTrans VALUES ('Fill Log') "IzAvKPM
DELETE DummyTrans RIXeV*ix
SELECT @Counter = @Counter + 1 |6bvUFr
END oj Y.6w
EXEC (@TruncLog) l+P!I{n
END b)KEB9w
SELECT 'Final Size of ' + db_name() + ' LOG is ' + `MPR-"Z6
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + k &J;,)V
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' JfWkg`LqL
FROM sysfiles axvZA:l
WHERE name = @LogicalFileName ph6'(,
DROP TABLE DummyTrans tyW}=xs
SET NOCOUNT OFF uuwJ-
8、说明:更改某个表 c(
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exec sp_changeobjectowner 'tablename','dbo' !"qT2<A
9、存储更改全部表 [niFJIsc
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch R3_OCM_*
@OldOwner as NVARCHAR(128), [.xY>\e
@NewOwner as NVARCHAR(128) qm><}N7f
AS s) U1U6O
DECLARE @Name as NVARCHAR(128) Qe_{<E
DECLARE @Owner as NVARCHAR(128) >xS({1A}
DECLARE @OwnerName as NVARCHAR(128) 1-?i*C
DECLARE curObject CURSOR FOR "J+L]IC?AD
select 'Name' = name, "0jwCX
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'Owner' = user_name(uid) Q%d%Io\-t
from sysobjects erUK;+2g
where user_name(uid)=@OldOwner (i%bQZt^?
order by name /fb}]e]N
OPEN curObject J+IItO4%
FETCH NEXT FROM curObject INTO @Name, @Owner f<