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。 _80L/92
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一、基础 SE^l`.U@
1、说明:创建数据库 _0'X!1"
CREATE DATABASE database-name rXD:^wUSc
2、说明:删除数据库 )lS04|s
drop database dbname GPhhg
3、说明:备份sql server v G\J8s
--- 创建 备份数据的 device 4=|Q2qgFV
USE master `pZX!6Wn
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' =d^hiR!GN
--- 开始 备份 ~//E'V-
BACKUP DATABASE pubs TO testBack 4aBVO%t
4、说明:创建新表 9cP{u$
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) }s<;YC
根据已有的表创建新表: ,
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A:create table tab_new like tab_old (使用旧表创建新表) X 5
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B:create table tab_new as select col1,col2... from tab_old definition only i({\fb|0
5、说明:删除新表 rnhLv$
drop table tabname m+s*Io{Ip
6、说明:增加一个列 2 A!*8w
Alter table tabname add column col type HB5-B XBU
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。 S!=R\_{u$
7、说明:添加主键: Alter table tabname add primary key(col) FP=-
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说明:删除主键: Alter table tabname drop primary key(col) =wDXlAQ
8、说明:创建索引:create [unique] index idxname on tabname(col....) g*YA~J@
删除索引:drop index idxname f*Q9u >1p
注:索引是不可更改的,想更改必须删除重新建。 v:/!OvLe
9、说明:创建视图:create view viewname as select statement
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删除视图:drop view viewname 'ZMh<M[
10、说明:几个简单的基本的sql语句 >(igVaZ>
选择:select * from table1 where 范围 e8xq`:4Y
插入:insert into table1(field1,field2) values(value1,value2) W5`p Qdk
删除:delete from table1 where 范围 CQ/+- -o
更新:update table1 set field1=value1 where 范围 Eq;w5;7s
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! Nr>UZlU8
排序:select * from table1 order by field1,field2 [desc] L{F]uz_[x
总数:select count as totalcount from table1 jwE=
求和:select sum(field1) as sumvalue from table1 <Y}m/-sD5
平均:select avg(field1) as avgvalue from table1 zE$HHY2ovi
最大:select max(field1) as maxvalue from table1 !PEKMDh
最小:select min(field1) as minvalue from table1 FauASu,A
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11、说明:几个高级查询运算词 `+\$
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A: UNION 运算符 ~=OJCKv5(
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。 ]9w)0iH
B: EXCEPT 运算符 ,>6a)2xh
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。 &>+T*-'
C: INTERSECT 运算符 Q?>r:vMi
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。 e3CFW_p
注:使用运算词的几个查询结果行必须是一致的。 ky[Cx!81C
12、说明:使用外连接 oOI0q_bf
A、left outer join: kGAgXtE
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。 <H60rON
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 TU~y;:OJ
B:right outer join: ZOV,yuD{8{
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。 HLV8_~gQPf
C:full outer join: U3:|!CC)T
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。 F=e;[uK\
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二、提升 UG`~RO
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) Y(7&3+'K
法一:select * into b from a where 1<>1 @~ke=w6&pe
法二:select top 0 * into b from a |Vz)!M
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ms}o[Z@n
insert into b(a, b, c) select d,e,f from b; \X*y~)+K`
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) LZ_VLW9wE
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ,S`n?.&& 7
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 5O]tkHYR
4、说明:子查询(表名1:a 表名2:b)
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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) |Sjy
5、说明:显示文章、提交人和最后回复时间 /FXvrH(
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b :~8@fEKb{
6、说明:外连接查询(表名1:a 表名2:b) ]aF;
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c >@ 8'C"F
7、说明:在线视图查询(表名1:a ) _4Eq_w`
select * from (SELECT a,b,c FROM a) T where t.a > 1; d9TTAaf
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 Y3[KS;_fr9
select * from table1 where time between time1 and time2 i3|xdYe$
select a,b,c, from table1 where a not between 数值1 and 数值2 8/)\nV$0Y
9、说明:in 的使用方法 `H:`JBe=+[
select * from table1 where a [not] in ('值1','值2','值4','值6') u,8)M'UU
10、说明:两张关联表,删除主表中已经在副表中没有的信息 klQmo30i
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) +:jonN9d
11、说明:四表联查问题: >uYQt~s
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 ..... 8493Sw
12、说明:日程安排提前五分钟提醒 KM[0aXOtv
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 d38o*+JCf
13、说明:一条sql 语句搞定数据库分页 MhHh`WUGh
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 Fw-Rv'\
14、说明:前10条记录 w" [T
select top 10 * form table1 where 范围 A r>JQ@0
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.) %zGv+H?
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ~Oq
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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 7M~ /
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(select a from tableA ) except (select a from tableB) except (select a from tableC) ?C fQwY#N
17、说明:随机取出10条数据 *Xk5H,:
select top 10 * from tablename order by newid() |33t 5}we
18、说明:随机选择记录 a~LA&>@
select newid() !^F_7u@Q
19、说明:删除重复记录 Iv
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) <]G'& iv>
20、说明:列出数据库里所有的表名 "A
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select name from sysobjects where type='U' T_Tu>wQX
21、说明:列出表里的所有的 !~?/D
select name from syscolumns where id=object_id('TableName') MCibYvc[
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。 P2jh[a%
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 dcmf~+T
显示结果: =6ru%.8U,
type vender pcs 1gBLJ0q
电脑 A 1 jcj8w
电脑 A 1 N}n3 +F
光盘 B 2 CQ6I4k
光盘 A 2 H0"'jd
手机 B 3 cFq<x=S
手机 C 3 <v -YMk@
23、说明:初始化表table1 !`Kg&t [&V
TRUNCATE TABLE table1 R$l-
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24、说明:选择从10到15的记录 r{r~!=u
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc \`~YW<D
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三、技巧 n;:.UGl9.
1、1=1,1=2的使用,在SQL语句组合时用的较多 O6?{@l
"where 1=1" 是表示选择全部 "where 1=2"全部不选, <FBH;}]
如: Fl($0}ER
if @strWhere !='' o[KZm17
begin :t`W&z41
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere oZ/"^5
end GO2q"a
else p: z][I
begin !\{2s!l~
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' r3' DXP
end ?F]P=S:x
我们可以直接写成 Xux[
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere |(Wwh$
2、收缩数据库 *V:U\G
--重建索引 XZ.D<T"
DBCC REINDEX iP9]b&
DBCC INDEXDEFRAG XYP
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--收缩数据和日志 q
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DBCC SHRINKDB Peph..8 Z
DBCC SHRINKFILE y>t:flD*
3、压缩数据库 `T+>E0H(f
dbcc shrinkdatabase(dbname) ;rT/gwg!
4、转移数据库给新用户以已存在用户权限 ]8 }2
exec sp_change_users_login 'update_one','newname','oldname' ws`r\k]3J
go x7E] }h
5、检查备份集 \,/ozfJ7dT
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' rG~W=!bj
6、修复数据库 B=]L%~xL$
ALTER DATABASE [dvbbs] SET SINGLE_USER /2T
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GO \; '#8
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK d!T,fz/-.
GO 4$vUD1('
ALTER DATABASE [dvbbs] SET MULTI_USER v7@"9Uw}
GO 5|eX@?QF58
7、日志清除 J&'*N:d
SET NOCOUNT ON d_$0
DECLARE @LogicalFileName sysname, -:d{x#
@MaxMinutes INT, ~b#<HG\,,
@NewSize INT t*Ro2QZ
USE tablename -- 要操作的数据库名 f2gh|p`
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 rz|Sjtq
@MaxMinutes = 10, -- Limit on time allowed to wrap log. 'qiAmaX
@NewSize = 1 -- 你想设定的日志文件的大小(M) mz1m^p)~{
-- Setup / initialize AaB1H7r-
DECLARE @OriginalSize int ulN1z
SELECT @OriginalSize = size _z%\53h
FROM sysfiles S6bYd`
WHERE name = @LogicalFileName R?lTB3"
SELECT 'Original Size of ' + db_name() + ' LOG is ' + '=+N
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CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 9=iMP~?xF
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' Y{e,I-"{
FROM sysfiles
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WHERE name = @LogicalFileName lrHN6:x(Y4
CREATE TABLE DummyTrans -}T7F+
(DummyColumn char (8000) not null) \NDW@!X
DECLARE @Counter INT, :n~Mg{j3
@StartTime DATETIME, H&*&n}vh5y
@TruncLog VARCHAR(255) >#r0k|3J^J
SELECT @StartTime = GETDATE(), o-_,l
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@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' In%FOPO
DBCC SHRINKFILE (@LogicalFileName, @NewSize) .Gr"|uII
EXEC (@TruncLog) M-Vz$D/aed
-- Wrap the log if necessary. 2<0".5+I
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired {c?{M.R
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) lws.;abm%n
AND (@OriginalSize * 8 /1024) > @NewSize p[WlcbBwT
BEGIN -- Outer loop. dmkGIg}
SELECT @Counter = 0 A6_ER&9$>N
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) VrT-6r'Y
BEGIN -- update `3[W~Cq
INSERT DummyTrans VALUES ('Fill Log') M^l%*QF[,q
DELETE DummyTrans b?Q$UMAbH
SELECT @Counter = @Counter + 1 mg70%=qM0f
END ||cI~qg
EXEC (@TruncLog) BH}rg,]G
END X eis_
SELECT 'Final Size of ' + db_name() + ' LOG is ' + er
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CONVERT(VARCHAR(30),size) + ' 8K pages or ' + *pS3xit~
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' \N? lG q
FROM sysfiles H<^3H
WHERE name = @LogicalFileName mDwuJf8}
DROP TABLE DummyTrans e5FF'~A%]
SET NOCOUNT OFF H_Hr=_8}-
8、说明:更改某个表 IwbV+mWQ
exec sp_changeobjectowner 'tablename','dbo' tQxAZ0B^
9、存储更改全部表 th"Aatmp
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch kJ.7C
@OldOwner as NVARCHAR(128), g:c?%J
@NewOwner as NVARCHAR(128) g rQ,J
AS FDGzh/
DECLARE @Name as NVARCHAR(128) 5K|`RzZ`B$
DECLARE @Owner as NVARCHAR(128) ed/
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DECLARE @OwnerName as NVARCHAR(128) _iqaKYT$
DECLARE curObject CURSOR FOR '|tmmoY6a:
select 'Name' = name,
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'Owner' = user_name(uid) 2I=4l
from sysobjects \dB z-H'@
where user_name(uid)=@OldOwner 54]UfmT%I
order by name tC+11M
OPEN curObject 4
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FETCH NEXT FROM curObject INTO @Name, @Owner A i#~Eu*
WHILE(@@FETCH_STATUS=0) Fkqw#s(T
BEGIN #;P-*P
if @Owner=@OldOwner =ZV+*cCC=q
begin =jG."o
set @OwnerName = @OldOwner + '.' + rtrim(@Name) bI;u};v
exec sp_changeobjectowner @OwnerName, @NewOwner uqBV KE
end x f:|lQf
-- select @name,@NewOwner,@OldOwner j3?@p5E(
FETCH NEXT FROM curObject INTO @Name, @Owner eY:jVYG(
END 1B{u4w7S4e
close curObject >T14
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deallocate curObject ]>+ teG:4
GO IS{>(XT{
10、SQL SERVER中直接循环写入数据 N40DL_-
declare @i int gHH[QLD=I
set @i=1 !|,djo!N
while @i<30 9PR?'X;4
begin 5G#2#Al(F
insert into test (userid) values(@i) %:-2P
set @i=@i+1 Qyj:!-o
end .T~Oc'wGo
小记存储过程中经常用到的本周,本月,本年函数 I^``x+a
Dateadd(wk,datediff(wk,0,getdate()),-1) vWYU'_=
Dateadd(wk,datediff(wk,0,getdate()),6) T' )l
Dateadd(mm,datediff(mm,0,getdate()),0) YipL_&-
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) R{Me~L?
Dateadd(yy,datediff(yy,0,getdate()),0) <)oW
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) |s !7U
上面的SQL代码只是一个时间段 n8) eC2A
Dateadd(wk,datediff(wk,0,getdate()),-1) >
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Dateadd(wk,datediff(wk,0,getdate()),6) k`0m|<$
就是表示本周时间段. D'_w
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下面的SQL的条件部分,就是查询时间段在本周范围内的: J}VG4}L
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) @$|bMH*1:
而在存储过程中 K@!Gs'Op
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 0SDyE
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) KA9v?_@{ F