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。 yr[HuwU
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一、基础 qGhwbg
1、说明:创建数据库 Br}0dha3E
CREATE DATABASE database-name m-AW}1:\f
2、说明:删除数据库 )o N#%%SB<
drop database dbname ZB'ms[
3、说明:备份sql server v?<Tkw ^F
--- 创建 备份数据的 device Yue#
USE master IRY/0v
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' -esq]c%3
--- 开始 备份 P+(q38f[
BACKUP DATABASE pubs TO testBack m5kt
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4、说明:创建新表 @3WI7q4
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) DEN (pA\
根据已有的表创建新表: ]`T*}$|
A:create table tab_new like tab_old (使用旧表创建新表) ^#p+#_*V
B:create table tab_new as select col1,col2... from tab_old definition only i$"M'BG
5、说明:删除新表 4Tn97G7
drop table tabname vf/|b6'y
6、说明:增加一个列 |0s)aV|K
Alter table tabname add column col type y#?AW`|
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。 AEO7I
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7、说明:添加主键: Alter table tabname add primary key(col) M 0Vs9K=
说明:删除主键: Alter table tabname drop primary key(col) &A)u!l Ue
8、说明:创建索引:create [unique] index idxname on tabname(col....) ]v|n'D-?
删除索引:drop index idxname Gid6,J
注:索引是不可更改的,想更改必须删除重新建。 ]~t4E'y)z
9、说明:创建视图:create view viewname as select statement v i~NfD@s
删除视图:drop view viewname qN@0k>11?
10、说明:几个简单的基本的sql语句 ]>H'CM4JR
选择:select * from table1 where 范围 %Z!3[.%F
插入:insert into table1(field1,field2) values(value1,value2) !6pE0(V^+4
删除:delete from table1 where 范围 6<
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更新:update table1 set field1=value1 where 范围 k:*(..!0z
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! Cs?[
排序:select * from table1 order by field1,field2 [desc] @78%6KZ`i
总数:select count as totalcount from table1 -0:Equ?pz
求和:select sum(field1) as sumvalue from table1 /;9iDjG
平均:select avg(field1) as avgvalue from table1 'FN+BvD
最大:select max(field1) as maxvalue from table1 q-R'5p\C?|
最小:select min(field1) as minvalue from table1 ~xakz BE
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11、说明:几个高级查询运算词 j@C*kj;-
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A: UNION 运算符 *Fu;sR2y%:
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。 :WHbwu,L$
B: EXCEPT 运算符 tVqc!][
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。 1`v$R0`!
C: INTERSECT 运算符 84jA)
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 M\6u4p!G!
注:使用运算词的几个查询结果行必须是一致的。 oa2v/P1`
12、说明:使用外连接 XI7:y4M
A、left outer join: hB??~>i3
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 b|E1>TkY
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c rUWC=?Q
B:right outer join: f0]`TjY
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 Vk?US&1q}
C:full outer join: }Sv\$h
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 x
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二、提升 Q5>]f/LD
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) &hSF
法一:select * into b from a where 1<>1 Kl]LnN%A{
法二:select top 0 * into b from a ZP;WXB`
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) q^^&nz<A
insert into b(a, b, c) select d,e,f from b; .$N8cYu0
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) 2'5u}G9
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ?
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例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. WNWtQ2]
4、说明:子查询(表名1:a 表名2:b) >v1ajI>O&{
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) >%i]p
5、说明:显示文章、提交人和最后回复时间 .y^T3?}I
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b Zg/
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6、说明:外连接查询(表名1:a 表名2:b) xF])NZy|
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c $0P7^4)w:
7、说明:在线视图查询(表名1:a ) r(DW,xoK0
select * from (SELECT a,b,c FROM a) T where t.a > 1; -cL wjI
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 Lu9`(+
select * from table1 where time between time1 and time2 <)VNEy'
select a,b,c, from table1 where a not between 数值1 and 数值2 $.T\dm-
9、说明:in 的使用方法 |eEXCn3{
select * from table1 where a [not] in ('值1','值2','值4','值6') k btQ
10、说明:两张关联表,删除主表中已经在副表中没有的信息 1y7FvD~ v
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) gib'f@i ;
11、说明:四表联查问题: =v49[i
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 ..... ;QqC c!b
12、说明:日程安排提前五分钟提醒 /\d@A B^5I
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 MVOWJaT(Aq
13、说明:一条sql 语句搞定数据库分页 5[|ZceY
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 MoMxKmI
14、说明:前10条记录 !G~`5?CvE
select top 10 * form table1 where 范围 V6uh'2
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 jZIBMGc
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) -Gd@baV
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 j+NsNIJq
(select a from tableA ) except (select a from tableB) except (select a from tableC) `!l Qd}W
17、说明:随机取出10条数据 l } WvO]
select top 10 * from tablename order by newid() O
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18、说明:随机选择记录 "eZ~]m}L0
select newid() (%SKTM
19、说明:删除重复记录 cs0rz= ZdH
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ]Pf!wv
20、说明:列出数据库里所有的表名 -E>LB\[t)
select name from sysobjects where type='U'
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21、说明:列出表里的所有的 zr^"zcfz&
select name from syscolumns where id=object_id('TableName') z\c$$+t
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。 ;(Kj-,>
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 }-T
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显示结果: [,Fu2j]
type vender pcs 2g$;ZBHO|8
电脑 A 1 IyoitIbLl
电脑 A 1 "V{v*Aei0
光盘 B 2 yt1dYF0Xq
光盘 A 2 m t}3/d
手机 B 3 |)+45e
手机 C 3 )| 0(#R
23、说明:初始化表table1 \vF*n Z5/
TRUNCATE TABLE table1 V* H7m'za
24、说明:选择从10到15的记录 _FP'SVa}D
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc m\@ q2l-
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三、技巧 k@^T<Ci
1、1=1,1=2的使用,在SQL语句组合时用的较多 ^EcwY- Qr
"where 1=1" 是表示选择全部 "where 1=2"全部不选, }E#1Z\)
如: w 3$9
if @strWhere !='' >8%O;3-m#
begin ie}?}s
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere A O3MlK9t
end Lv7$@|"H9
else z@U5
begin .wf$]oQQ
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' #D
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end wkKSL
我们可以直接写成 <~n%=^knE
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere g]jCR*]
2、收缩数据库 k FCdGl
--重建索引 ,$bK)|pGV
DBCC REINDEX e,Sxu[2
DBCC INDEXDEFRAG ,"?xy-6
--收缩数据和日志 !+_X q$9_
DBCC SHRINKDB <8BNqbX
DBCC SHRINKFILE Ah_0o_Di
3、压缩数据库
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dbcc shrinkdatabase(dbname) \T {<{<n
4、转移数据库给新用户以已存在用户权限 fF.sT7Az+
exec sp_change_users_login 'update_one','newname','oldname' 1;JH0~403
go RSBk^
5、检查备份集 L16">,5
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' S)x5.vo^
6、修复数据库 RKb (
ALTER DATABASE [dvbbs] SET SINGLE_USER x,UP7=6
GO U(5 Yg
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK &VT O9d
GO $PFE>=nM
ALTER DATABASE [dvbbs] SET MULTI_USER zXML<?w
GO wW|[Im&
7、日志清除 +Sak_*fq
SET NOCOUNT ON tC\(H=ecP
DECLARE @LogicalFileName sysname, MS;^@>|wj
@MaxMinutes INT, 6"/4@?
@NewSize INT a]@BS6
USE tablename -- 要操作的数据库名 (w-@b70E
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ^1;Eq>u
@MaxMinutes = 10, -- Limit on time allowed to wrap log. o ^""=Z
@NewSize = 1 -- 你想设定的日志文件的大小(M) r>g5_"FL
-- Setup / initialize qqSFy>`P
DECLARE @OriginalSize int UnOcw
SELECT @OriginalSize = size Bb.U4#
FROM sysfiles nx@,oC4
WHERE name = @LogicalFileName BVu{To:g
SELECT 'Original Size of ' + db_name() + ' LOG is ' + iC~ll!FA!
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 3f(tb%pa5
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' F
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FROM sysfiles -l?\hmDl
WHERE name = @LogicalFileName @4=Az1W*
CREATE TABLE DummyTrans F$jfPy-f
(DummyColumn char (8000) not null) ;),vUu,k
DECLARE @Counter INT, yaPx=^&
@StartTime DATETIME, t"P:}ps{?
@TruncLog VARCHAR(255) 8~AL+*hn
SELECT @StartTime = GETDATE(), ~L:H]_8F l
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' #'BPW<Ob
DBCC SHRINKFILE (@LogicalFileName, @NewSize) +h8`8k'}-2
EXEC (@TruncLog) #]r'?GN
-- Wrap the log if necessary. 4@QR2K|
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired +!)_[ zo
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 1v 4M*
AND (@OriginalSize * 8 /1024) > @NewSize g0#w
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BEGIN -- Outer loop. ~>XqR/v
SELECT @Counter = 0 eIQ@){lJ-]
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) !,R=6b$E5
BEGIN -- update sQn@:Gk
INSERT DummyTrans VALUES ('Fill Log') u{S"NEc
DELETE DummyTrans 77-G*PI*I
SELECT @Counter = @Counter + 1 OO\$'%
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END (U@$gkUx}G
EXEC (@TruncLog) ZqXp f
END _gw paAJ
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 1p8hn!V
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 3sp-0tUE
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 1rON8=E
FROM sysfiles 51xf.iB
WHERE name = @LogicalFileName pA6A*~QE
DROP TABLE DummyTrans g]E3+: 5dk
SET NOCOUNT OFF C8D`:k
8、说明:更改某个表 KbMan~Pb6
exec sp_changeobjectowner 'tablename','dbo' Ey%KbvNv
9、存储更改全部表 e-#Vs{?|r
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch I3u)y|Y=
@OldOwner as NVARCHAR(128), CZf38$6 X
@NewOwner as NVARCHAR(128) qB3E
AS T3@34}*
DECLARE @Name as NVARCHAR(128) 8RQv
DECLARE @Owner as NVARCHAR(128) dSe d6
DECLARE @OwnerName as NVARCHAR(128) BZ(I]:oDL
DECLARE curObject CURSOR FOR 'mZQ}U=<
select 'Name' = name, 28vQ
'Owner' = user_name(uid) "28zLo3
from sysobjects wo;OkJKF
where user_name(uid)=@OldOwner u:^sEk"Lk'
order by name 0{
OPEN curObject BN~ndWRK
FETCH NEXT FROM curObject INTO @Name, @Owner Ss_}@p ^
WHILE(@@FETCH_STATUS=0) =.w~qL
BEGIN ^?*<.rsG
if @Owner=@OldOwner #q W#>0U
begin 5vJxhBm/
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 3R-5&!i
exec sp_changeobjectowner @OwnerName, @NewOwner L|B! ]}
end v7\rW{~Jd&
-- select @name,@NewOwner,@OldOwner VfUHqdg-
FETCH NEXT FROM curObject INTO @Name, @Owner 8H|ac[hXK2
END >P]gjYN
close curObject .R
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deallocate curObject `F3wO!
GO 1}Y3|QxF
10、SQL SERVER中直接循环写入数据 EWQLLH "h
declare @i int _EJP I
set @i=1 %k~ezn
while @i<30 !qU1RdZ
begin K)5j
insert into test (userid) values(@i) SPXvi0Jg
set @i=@i+1 9Q!Z9n"8~)
end g> ~+M
小记存储过程中经常用到的本周,本月,本年函数 vn!3Z! dm(
Dateadd(wk,datediff(wk,0,getdate()),-1) w*&vH/D
Dateadd(wk,datediff(wk,0,getdate()),6) `WnsM;1Y"
Dateadd(mm,datediff(mm,0,getdate()),0) (=%0$(S>
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) [ D.%v~j
Dateadd(yy,datediff(yy,0,getdate()),0) *,IK4F6>:
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) T]nAz<l),
上面的SQL代码只是一个时间段 r)OiiD"
Dateadd(wk,datediff(wk,0,getdate()),-1) iQS,@6
Dateadd(wk,datediff(wk,0,getdate()),6) 2dcvB]T!
就是表示本周时间段. _ Yc"{d3S
下面的SQL的条件部分,就是查询时间段在本周范围内的: !zllvtK4
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 5-y*]:g(
而在存储过程中 ;8dffsyq
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) /|<SD.:
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 2ij&Db/