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。 .@ 1\26<
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一、基础 sQTW?KA-Te
1、说明:创建数据库 ~EX/IIa{
CREATE DATABASE database-name B4U+q|OD#
2、说明:删除数据库 !aIIjWz]
drop database dbname 5r`g6@
3、说明:备份sql server +F+jC9j(<
--- 创建 备份数据的 device }bjTb!
USE master 'nW:2(J
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 5k<HO _]
--- 开始 备份 l|5ss{llR
BACKUP DATABASE pubs TO testBack *3.
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4、说明:创建新表 mlIc`GSI
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) =`.9 V<
根据已有的表创建新表: & ({X9
A:create table tab_new like tab_old (使用旧表创建新表) ihs@
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B:create table tab_new as select col1,col2... from tab_old definition only 6VCw>x
5、说明:删除新表 C 5)G^
drop table tabname o5AyJuS-u$
6、说明:增加一个列 ]]9eUw=
Alter table tabname add column col type "4Anh1,js
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。 'B6D&xn'%&
7、说明:添加主键: Alter table tabname add primary key(col) O+z-6:`
说明:删除主键: Alter table tabname drop primary key(col) %Z.>)R4
8、说明:创建索引:create [unique] index idxname on tabname(col....) udW,
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删除索引:drop index idxname m!!uf/
注:索引是不可更改的,想更改必须删除重新建。 [.|tD
9、说明:创建视图:create view viewname as select statement a-8~f8na{(
删除视图:drop view viewname i[WTp??Uv
10、说明:几个简单的基本的sql语句 U4^dDj
选择:select * from table1 where 范围 rK)%n!Z
插入:insert into table1(field1,field2) values(value1,value2) 7F.>M
删除:delete from table1 where 范围 #WfJz}P,!
更新:update table1 set field1=value1 where 范围 $+V{2k4X,
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! sF(U?)48
排序:select * from table1 order by field1,field2 [desc] K;S&91V)=
总数:select count as totalcount from table1
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求和:select sum(field1) as sumvalue from table1 D|_}~T>;&
平均:select avg(field1) as avgvalue from table1 >Li
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最大:select max(field1) as maxvalue from table1 r ZGA9duy
最小:select min(field1) as minvalue from table1 >(d+E\!A
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11、说明:几个高级查询运算词 Q_M2!qj
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A: UNION 运算符 [o>/2
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。 pE15[fJ`
B: EXCEPT 运算符 jS|(g##4
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。 `^|mNh
C: INTERSECT 运算符 $]Y' [pE@
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 a08B8
注:使用运算词的几个查询结果行必须是一致的。 7r*>?]y+
12、说明:使用外连接 574b]
A、left outer join: ZtDHNL
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 aJIj%Y$
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?FZu,h}
B:right outer join: `p'L3u5H-
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。 Y5Ey%Mm6
C:full outer join: M>1V3sM
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。 <}.)kg${O
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二、提升 )M^;6S
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) b]CJf8'u
法一:select * into b from a where 1<>1 M`iJ6L
法二:select top 0 * into b from a aLhTaB-va
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) zKgW9j<(
insert into b(a, b, c) select d,e,f from b; LF{ qI?LG
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) *1%=?:$(r6
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 P),%S9jP;
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. NL2n\%n
4、说明:子查询(表名1:a 表名2:b) H+_oK
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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) x"U/M?l
5、说明:显示文章、提交人和最后回复时间 213D{#2
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b
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6、说明:外连接查询(表名1:a 表名2:b) 9-p d{Z~l
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c :sM|~gT
7、说明:在线视图查询(表名1:a ) ("mW=Ln
select * from (SELECT a,b,c FROM a) T where t.a > 1; G{ F>=z"(l
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 r_
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select * from table1 where time between time1 and time2 {TUCa
select a,b,c, from table1 where a not between 数值1 and 数值2 {`l]RIig
9、说明:in 的使用方法 IcaIB)
select * from table1 where a [not] in ('值1','值2','值4','值6') qY#*zx
10、说明:两张关联表,删除主表中已经在副表中没有的信息 c|ZZ+2IYd
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) _VR4|)1g
11、说明:四表联查问题: XTHrf'BU
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 ..... 'KyT]OObS
12、说明:日程安排提前五分钟提醒 K\n %&w
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 $m{\<A
13、说明:一条sql 语句搞定数据库分页 Wpj.G
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 j>0S3P,
14、说明:前10条记录 |!IJ/ivEgw
select top 10 * form table1 where 范围 ?55('+{l
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.) PS \QbA
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) EA?:GtH
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 I~4`NV0
(select a from tableA ) except (select a from tableB) except (select a from tableC) bFJmXx&
17、说明:随机取出10条数据 w)DO"Z7
select top 10 * from tablename order by newid() V<ODt%
18、说明:随机选择记录 T|9Yo=UK%
select newid() 5)&e2V',y
19、说明:删除重复记录 vP&*(WfO)
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ?86h:9
20、说明:列出数据库里所有的表名 Bg7?1m
select name from sysobjects where type='U' <J`_Qc8C
21、说明:列出表里的所有的 {"4t`dM
select name from syscolumns where id=object_id('TableName') 9chiu%20
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。 AS4m227
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 $Q]`+:g*}
显示结果: 7e}p:Vfp
type vender pcs r@s, cCK9?
电脑 A 1 ]l+2Ca:-[j
电脑 A 1 ub.pJJlC
光盘 B 2 :!{aey
光盘 A 2 uiHlaMf
手机 B 3 `EWeJ(4Z@
手机 C 3 X3a:*1N
23、说明:初始化表table1 b/ZX}<s(1=
TRUNCATE TABLE table1 :(I)+;M}P
24、说明:选择从10到15的记录 !?Ow"i-lp
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc _k6N(c2Nd
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三、技巧 f_;3|i
1、1=1,1=2的使用,在SQL语句组合时用的较多 SOP=
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"where 1=1" 是表示选择全部 "where 1=2"全部不选, <<n8 P5pXt
如: F!a YK2
if @strWhere !='' ~{+J~5!;<H
begin t7)Y@gRy
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere Lg9ktRKK
end xx/DD%IZ
else T
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begin U0)(k}Q)
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' Qy4AuMU2
end Z/Mp=273
我们可以直接写成 Za=<euc7
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere :Z1_;`>CT
2、收缩数据库 QKHm OVh]
--重建索引 rZ0@GA
DBCC REINDEX XUMCz7&j
DBCC INDEXDEFRAG )%#hpP M^
--收缩数据和日志 a#G7pZX/I}
DBCC SHRINKDB 3OM\R%M
DBCC SHRINKFILE qZ8lU
3、压缩数据库 rV2}> k
dbcc shrinkdatabase(dbname) n,xK7icYNQ
4、转移数据库给新用户以已存在用户权限 Do2y7,jv
exec sp_change_users_login 'update_one','newname','oldname' S"N@.n[
go LU;ma((yy[
5、检查备份集 c}rRNS$F
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ;{HxY98Q
6、修复数据库 -AcQ_dS
ALTER DATABASE [dvbbs] SET SINGLE_USER U*1~Zf
GO QuF%m^aE
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK
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GO guFR5>-L
ALTER DATABASE [dvbbs] SET MULTI_USER =YPWt>\a}
GO LM*9b
7、日志清除 CR,
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SET NOCOUNT ON a?+) K
DECLARE @LogicalFileName sysname, Z39^nGO
@MaxMinutes INT, >1joCG~
@NewSize INT &dOV0y_
USE tablename -- 要操作的数据库名 Q[~O`Lz
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 p&ow\AO
@MaxMinutes = 10, -- Limit on time allowed to wrap log. uP+
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@NewSize = 1 -- 你想设定的日志文件的大小(M) `o:)PTQNg
-- Setup / initialize $ g1p!
DECLARE @OriginalSize int " I _T
SELECT @OriginalSize = size 1
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FROM sysfiles BDB-OJ
WHERE name = @LogicalFileName fnB-?8K<
SELECT 'Original Size of ' + db_name() + ' LOG is ' + UbMcXH8=F
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + xFyMg&
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' !q7M+j4
FROM sysfiles xnh%nv<v{
WHERE name = @LogicalFileName hXMC!~Th
CREATE TABLE DummyTrans EaP#~x
(DummyColumn char (8000) not null) R`
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DECLARE @Counter INT, .cu5h
@StartTime DATETIME, 9N'$Y*. d<
@TruncLog VARCHAR(255) WpmypkJA#
SELECT @StartTime = GETDATE(), "rAm6b-`
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' .X:{s,@
DBCC SHRINKFILE (@LogicalFileName, @NewSize) [Q^kO;
EXEC (@TruncLog) I
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-- Wrap the log if necessary. \&e+f#!u
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired ^g~-$ t<!
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) M{nz~W80
AND (@OriginalSize * 8 /1024) > @NewSize UejG$JyHP
BEGIN -- Outer loop. B]]M?pS
SELECT @Counter = 0 =Oo*7|Z
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000))
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BEGIN -- update 6^ /C+zuX
INSERT DummyTrans VALUES ('Fill Log') %|-Rh^H[JK
DELETE DummyTrans ytAhhwN~
SELECT @Counter = @Counter + 1 ngdVRJL
END czHO)uQ?d`
EXEC (@TruncLog) G~m(&,:Mu
END V8,$<1Fi;-
SELECT 'Final Size of ' + db_name() + ' LOG is ' + yn%w'
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + co~TQpy^
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' <(^-o4Cl
FROM sysfiles ^2=Jv.2{|
WHERE name = @LogicalFileName ]%mg(&p4
DROP TABLE DummyTrans YY]LK%-
SET NOCOUNT OFF 4Y-9W2s
8、说明:更改某个表 o+aB[+
exec sp_changeobjectowner 'tablename','dbo' qrt+{5/t
9、存储更改全部表 2;kab^iv'
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch ,,{Uz)>'W6
@OldOwner as NVARCHAR(128), :uI}"Bp
@NewOwner as NVARCHAR(128) <|m"Q!f
AS KDn`XCnk,
DECLARE @Name as NVARCHAR(128) Sfvi|kZX
DECLARE @Owner as NVARCHAR(128) O#k?c }
DECLARE @OwnerName as NVARCHAR(128) hcN$p2-
DECLARE curObject CURSOR FOR _L:
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select 'Name' = name, *$hO C%(
'Owner' = user_name(uid) >,~JQ%1
from sysobjects xJO[pT v
where user_name(uid)=@OldOwner 5Impv3qaZ
order by name u
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OPEN curObject ! Noabt
FETCH NEXT FROM curObject INTO @Name, @Owner qv,|7yw{
WHILE(@@FETCH_STATUS=0) OZISh?
BEGIN tcRK\
if @Owner=@OldOwner w5&UG/z%l
begin q.g!WLiI
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 6
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exec sp_changeobjectowner @OwnerName, @NewOwner 1F$a
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end G LE`ba
-- select @name,@NewOwner,@OldOwner {8UBxFIM(
FETCH NEXT FROM curObject INTO @Name, @Owner ^U`[P@T
END 0<^K0>lm
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close curObject "ENgu/A!
deallocate curObject Ay2|@1e
GO *1elUI2Rg
10、SQL SERVER中直接循环写入数据 Duz}e80
declare @i int >iG`
set @i=1 xy|;WB
while @i<30 >\@6i
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begin gbI0?G6XN/
insert into test (userid) values(@i) wuh$=fya
set @i=@i+1 Fa>Y]Y0r
end @c{Z?>dUc#
小记存储过程中经常用到的本周,本月,本年函数 ^ 0TJys%
Dateadd(wk,datediff(wk,0,getdate()),-1) ]cA){^.Jz
Dateadd(wk,datediff(wk,0,getdate()),6) 6aj)Fe'2
Dateadd(mm,datediff(mm,0,getdate()),0) NIYAcLa@n8
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ^K;,,s;0
Dateadd(yy,datediff(yy,0,getdate()),0) 0?sIod
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 35c9c(A
上面的SQL代码只是一个时间段 g0iV#i
Dateadd(wk,datediff(wk,0,getdate()),-1) }7&;YAt
Dateadd(wk,datediff(wk,0,getdate()),6) 0|NbU
就是表示本周时间段. jo"[$%0`
下面的SQL的条件部分,就是查询时间段在本周范围内的: ]" )i~-|R
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) [u-~<80
而在存储过程中 "5>p]u>
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) v3hNvcMpf
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) *1>XlVx,