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。 n/:Z{
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一、基础 JCBnFrP
1、说明:创建数据库 ,9+nfj
CREATE DATABASE database-name *+# k{D,
2、说明:删除数据库 T)*l' g'
drop database dbname sd7Y6?_C
3、说明:备份sql server i@%L_[MtA
--- 创建 备份数据的 device <`b|L9
USE master f61]`@Bk
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' l$qmn$Uc
--- 开始 备份 X]>[Qz)K^
BACKUP DATABASE pubs TO testBack K T"h74@
4、说明:创建新表 <4S F~i
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ~n)]dFy
根据已有的表创建新表: eq7C]i
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A:create table tab_new like tab_old (使用旧表创建新表) W>UjUq);
B:create table tab_new as select col1,col2... from tab_old definition only IrUpExJ
5、说明:删除新表 9 ?[4i'
drop table tabname rUhWZta
6、说明:增加一个列 047*gn.b
Alter table tabname add column col type (p'/p
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。 0!)U *+j,
7、说明:添加主键: Alter table tabname add primary key(col) d
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说明:删除主键: Alter table tabname drop primary key(col) vHoT@E#}'
8、说明:创建索引:create [unique] index idxname on tabname(col....) !k ;[^>
删除索引:drop index idxname ~6=Wq64
注:索引是不可更改的,想更改必须删除重新建。 %,h!: Ec^c
9、说明:创建视图:create view viewname as select statement ">rsA&hN-
删除视图:drop view viewname XP3QBq
10、说明:几个简单的基本的sql语句 3" 8t)s
选择:select * from table1 where 范围 F5Cqv0HV
插入:insert into table1(field1,field2) values(value1,value2) vQE` c@^{
删除:delete from table1 where 范围 GWVEIZ
更新:update table1 set field1=value1 where 范围 (p}9^Y
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! :a#|
排序:select * from table1 order by field1,field2 [desc] !;6W!%t.|
总数:select count as totalcount from table1 DWHOSXA4
求和:select sum(field1) as sumvalue from table1 @faF`8LwA
平均:select avg(field1) as avgvalue from table1 =/)Mc@Hb
最大:select max(field1) as maxvalue from table1 }"!6Xm
最小:select min(field1) as minvalue from table1 i@sCMCu6
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11、说明:几个高级查询运算词 F^J&g%ql
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A: UNION 运算符 8JFnB(3xU
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。 t ;bZc s
B: EXCEPT 运算符 $,!dan<eA
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。 |YMzp8Da(
C: INTERSECT 运算符 w`w `q'
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。 \f~u85
注:使用运算词的几个查询结果行必须是一致的。 >:(6{}b
12、说明:使用外连接 =Td#2V;0
A、left outer join: _&6juBb
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。
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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 <[*h_gE5
B:right outer join: ;5zjd,
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。 pO@k@JZ
C:full outer join: $NH`Iu9t
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 0YgFjd
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二、提升 H"kc^G+(R"
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) #w[q.+A
法一:select * into b from a where 1<>1 _Y:Ja0,
法二:select top 0 * into b from a C"V?yDy2~
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) X}ey0)g%
insert into b(a, b, c) select d,e,f from b; hvwnG>m\
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 23.y3t_?
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 MV:<w3!
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. Z)b)v
4、说明:子查询(表名1:a 表名2:b) ?et0W|^k
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) "oKj~:$
5、说明:显示文章、提交人和最后回复时间 Vf#oKPP1
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b !]UU;8h~
6、说明:外连接查询(表名1:a 表名2:b) 4 @ydK
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c rZwf%}
7、说明:在线视图查询(表名1:a ) 4rGO8R
select * from (SELECT a,b,c FROM a) T where t.a > 1; 4OB~h]Vc
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 y"%iD`{
select * from table1 where time between time1 and time2
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select a,b,c, from table1 where a not between 数值1 and 数值2 Z:r$;`K/
9、说明:in 的使用方法 Es ZnGuY
select * from table1 where a [not] in ('值1','值2','值4','值6') >"m@qkh
10、说明:两张关联表,删除主表中已经在副表中没有的信息 D| 8sjp4
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 8z3I~yL_`+
11、说明:四表联查问题: -X6\[I:+A
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 ..... E:LQ!
12、说明:日程安排提前五分钟提醒 -hJ>wGI
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 HquB*=^xh
13、说明:一条sql 语句搞定数据库分页 n8y ,{|
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 R-0_226
14、说明:前10条记录 071 E%u,
select top 10 * form table1 where 范围 NC[GtAPD3
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.) C$]%1<-Iv]
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ,sQ0atk7ma
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 U- U V<}
(select a from tableA ) except (select a from tableB) except (select a from tableC) 2rE~V.)%
17、说明:随机取出10条数据 H8Z Z@@ qm
select top 10 * from tablename order by newid() {O3oUE+
18、说明:随机选择记录 e-duZ o
select newid() DftGy:Ah3
19、说明:删除重复记录 0wa!pE"
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) J7 zVi
20、说明:列出数据库里所有的表名 !<UEq`2
select name from sysobjects where type='U' Z1MJ!{@6
21、说明:列出表里的所有的 0ga1Yr]
select name from syscolumns where id=object_id('TableName')
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22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 S
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select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type %I2xK.8=
显示结果: Z ^9{Qq
type vender pcs AcfkY m~
电脑 A 1 ^QL/m\zq@%
电脑 A 1 OKLggim{
光盘 B 2
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光盘 A 2 JWm^RQ
手机 B 3 @{$Cv"6769
手机 C 3 \Z7([G h
23、说明:初始化表table1 o\:f9JL
TRUNCATE TABLE table1 =-s20mdj
24、说明:选择从10到15的记录 f 7QUZb\
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc TG%hy"k
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三、技巧 +e3WwUx
1、1=1,1=2的使用,在SQL语句组合时用的较多 o-e,
"where 1=1" 是表示选择全部 "where 1=2"全部不选, { ves@p>?
如: 35]G_\
if @strWhere !='' >cr_^(UW&
begin zL!~,B8C
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere (gJ
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end lN`_0
else 2ZzD^:V[}
begin +h vIJv ?
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' "!_
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end U(&nh?
我们可以直接写成 '|A5a+[
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere xvz5\s|b
2、收缩数据库 MnrGD>M@|
--重建索引 g:3'x/a1
DBCC REINDEX QGCdeE$K
DBCC INDEXDEFRAG bCx1g/
--收缩数据和日志 cTIwA:)D
DBCC SHRINKDB CTrs\G
DBCC SHRINKFILE H*
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3、压缩数据库 +K?N:w
dbcc shrinkdatabase(dbname) kI[O {<kQ
4、转移数据库给新用户以已存在用户权限 my #u^O;
exec sp_change_users_login 'update_one','newname','oldname' "6o}qeB l
go V]PhXVJ
5、检查备份集 R_*D7|v
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' j?KB8oY`TP
6、修复数据库 pNf9
ALTER DATABASE [dvbbs] SET SINGLE_USER ]ieA?:0Hi
GO _Ag/gu2-?
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ~FCSq:_
GO JLV}Fw
ALTER DATABASE [dvbbs] SET MULTI_USER xS\QKnG.
GO W<hdb!bE
7、日志清除 |I^Jn@Mq:
SET NOCOUNT ON { )GEgC
DECLARE @LogicalFileName sysname, n#L2cv~Aj"
@MaxMinutes INT, @p` CAB
@NewSize INT 6UAxl3-\
USE tablename -- 要操作的数据库名 zam0(^=
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 0<]!G|;|
@MaxMinutes = 10, -- Limit on time allowed to wrap log. Zow^bzy4
@NewSize = 1 -- 你想设定的日志文件的大小(M) !m:PBl5
-- Setup / initialize 4l!Yop0h
DECLARE @OriginalSize int Y l3[~S
SELECT @OriginalSize = size 4bJ2<j
FROM sysfiles #vZ]2Ud=2
WHERE name = @LogicalFileName 0N[DV]
SELECT 'Original Size of ' + db_name() + ' LOG is ' + hz|z&vyP
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + {Ljl4Sp&
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ^?.:}
FROM sysfiles ]\mb6Hc
WHERE name = @LogicalFileName P;o>~Y>x
CREATE TABLE DummyTrans +FKP5L}
(DummyColumn char (8000) not null) BNoCE!
DECLARE @Counter INT, .q[sk
@StartTime DATETIME, @`+$d=rO`
@TruncLog VARCHAR(255) gsq[ 9
SELECT @StartTime = GETDATE(), f(MHU
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' LOG*K;v3
DBCC SHRINKFILE (@LogicalFileName, @NewSize) k@)m- K
EXEC (@TruncLog) }b\q<sNE{
-- Wrap the log if necessary. IS*"_o<AR
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired JOne&{h]J"
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) hA1hE?c`
AND (@OriginalSize * 8 /1024) > @NewSize vc{]c
}
BEGIN -- Outer loop. f I-"8f0_
SELECT @Counter = 0 F$y FR
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) h \cK
BEGIN -- update #cF8)GC
INSERT DummyTrans VALUES ('Fill Log') ao5yW;^y
DELETE DummyTrans ^V,/4u
SELECT @Counter = @Counter + 1 E6-(q!"A
END N$a-i
EXEC (@TruncLog) ; Kb[UZ1
END $>s@T(
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 7MJ)p$&
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + n~i4yn=
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 8jGoU9
FROM sysfiles `ip69 IF2*
WHERE name = @LogicalFileName %f(.OR)6{
DROP TABLE DummyTrans |oi49:NXn
SET NOCOUNT OFF _p2<7x i
8、说明:更改某个表 9@*>$6
exec sp_changeobjectowner 'tablename','dbo' 0bL=l0N$W
9、存储更改全部表 UT7lj wT
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch sW3D
(
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@OldOwner as NVARCHAR(128), oc%le2
@NewOwner as NVARCHAR(128) XlJux_LD:
AS
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DECLARE @Name as NVARCHAR(128) aYCzb7
DECLARE @Owner as NVARCHAR(128) 4xn^`xf9
DECLARE @OwnerName as NVARCHAR(128) V+ ~2q=
DECLARE curObject CURSOR FOR MCpK^7]k
select 'Name' = name, @gGuV$Mw
'Owner' = user_name(uid) {QkH%jj
from sysobjects +~.Jw#HqS
where user_name(uid)=@OldOwner Tka="eyIj3
order by name \~j(ui|
OPEN curObject ]_xGVwem
FETCH NEXT FROM curObject INTO @Name, @Owner 0]0M>vx
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WHILE(@@FETCH_STATUS=0) `ViNSr):J
BEGIN :>ST)Y@]w
if @Owner=@OldOwner < io8
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begin %=
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set @OwnerName = @OldOwner + '.' + rtrim(@Name) :@A;!'zpL
exec sp_changeobjectowner @OwnerName, @NewOwner OWfj<#}t+
end `;2`H, G'
-- select @name,@NewOwner,@OldOwner Xn'>k[}<k
FETCH NEXT FROM curObject INTO @Name, @Owner 19`0)pzZ*P
END JN-8\L
close curObject ' *C)S
deallocate curObject \eN/fTPm
GO 0DT2qM[,
10、SQL SERVER中直接循环写入数据 emIbGkH
declare @i int Pg C]@Q%
set @i=1 G"sc;nT
while @i<30 m 4LM10
begin dg8\(G
insert into test (userid) values(@i) E?o8'r
set @i=@i+1 pra&A2Y\
end <bppu>&
小记存储过程中经常用到的本周,本月,本年函数 r:Cid*~m
Dateadd(wk,datediff(wk,0,getdate()),-1) \1_&?(pU
Dateadd(wk,datediff(wk,0,getdate()),6) [M>_(u6
Dateadd(mm,datediff(mm,0,getdate()),0) [+7X&B
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) [kkcV5I-
Dateadd(yy,datediff(yy,0,getdate()),0) ?y@pRe$2
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) hG3Lj7)UH
上面的SQL代码只是一个时间段 F4gc_>{|
Dateadd(wk,datediff(wk,0,getdate()),-1) !qve1H4d2
Dateadd(wk,datediff(wk,0,getdate()),6) t4f\0`jN
就是表示本周时间段. VO?NrKyeW
下面的SQL的条件部分,就是查询时间段在本周范围内的: :?W:'% (`[
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) .;6bMP[YA
而在存储过程中 .1lc'gu5y
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) l6Bd<tSH
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) Bn:sN_N