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。 ;\<""Yj@l
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一、基础 +mJ
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1、说明:创建数据库 =E&b=
CREATE DATABASE database-name bH'S.RWp=
2、说明:删除数据库 ?r{TOjn
drop database dbname XOu+&wOu
3、说明:备份sql server w+t# Yb\7
--- 创建 备份数据的 device _REqT
USE master E)C.eW /
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' ~'NX~<m
--- 开始 备份 yOX&cZ[
BACKUP DATABASE pubs TO testBack O {PW
4、说明:创建新表 nAIH`L"X
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 9 wAA.
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根据已有的表创建新表: 9.xvV|Sp
A:create table tab_new like tab_old (使用旧表创建新表) Z8&4z.6_
B:create table tab_new as select col1,col2... from tab_old definition only MVeFe\r
5、说明:删除新表 F(d:t!
drop table tabname PXV)NC
6、说明:增加一个列 sB?2*S"X)<
Alter table tabname add column col type 8$\Za,)g
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 6tOCZ'f
7、说明:添加主键: Alter table tabname add primary key(col) ?Fce!J
说明:删除主键: Alter table tabname drop primary key(col) RTK}mhnV
8、说明:创建索引:create [unique] index idxname on tabname(col....) inYM+o!Ub
删除索引:drop index idxname J5O.*&
注:索引是不可更改的,想更改必须删除重新建。 ID)^vwn
9、说明:创建视图:create view viewname as select statement gh TcB
删除视图:drop view viewname qv
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10、说明:几个简单的基本的sql语句 :%N*{uy
选择:select * from table1 where 范围 wz|DT3"Xs
插入:insert into table1(field1,field2) values(value1,value2) z(+&wa
删除:delete from table1 where 范围 8s<^]sFP
更新:update table1 set field1=value1 where 范围 Ks#A<! ;=
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! zm3-C%:Bw
排序:select * from table1 order by field1,field2 [desc] /$;,F't#2M
总数:select count as totalcount from table1 w "{bp
求和:select sum(field1) as sumvalue from table1 &B}Lo
平均:select avg(field1) as avgvalue from table1 BYS lKTh
最大:select max(field1) as maxvalue from table1 $K})Q3FNi
最小:select min(field1) as minvalue from table1 d]8_l1O
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11、说明:几个高级查询运算词 qB:AkMd&
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A: UNION 运算符 'qjX$]H
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。 'fIHUw|
B: EXCEPT 运算符 rOW;yJ[
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。 Kv}k*A% S
C: INTERSECT 运算符 %MN.O-Lc
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。 e8oKn&
注:使用运算词的几个查询结果行必须是一致的。 fe|g3>/|
12、说明:使用外连接 S.: 7k9
A、left outer join: 6JSY56v
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。 P'sfi>A
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 :/6()_>bO
B:right outer join: E4r.ky`#~
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。 I FsE!oDs4
C:full outer join: ur6e&bTp
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。 #,&8&
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二、提升 ]KWK}Zyi
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) ys%zlbj[
法一:select * into b from a where 1<>1 !4t`Hv?'
法二:select top 0 * into b from a T6uMFD4 |
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) !{(ls<
insert into b(a, b, c) select d,e,f from b; `a
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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) +%XnMl
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 ]boE{R!I
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. +"8}R~`!
4、说明:子查询(表名1:a 表名2:b) yAG+] r
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) C',6%6P
5、说明:显示文章、提交人和最后回复时间 xIL#h@dz
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 0Gsu
6、说明:外连接查询(表名1:a 表名2:b) !"E-\cc'
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c (9]6bd
7、说明:在线视图查询(表名1:a ) -w]/7cH
select * from (SELECT a,b,c FROM a) T where t.a > 1; P$ucL~r
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 b/u8}
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select * from table1 where time between time1 and time2 J=iRul^S
select a,b,c, from table1 where a not between 数值1 and 数值2 89Z#|#uM5
9、说明:in 的使用方法 d; =u
select * from table1 where a [not] in ('值1','值2','值4','值6') (rcMA>2=
10、说明:两张关联表,删除主表中已经在副表中没有的信息 2 z7}+lH
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) qfYG.~`5
11、说明:四表联查问题: t`YWwI.
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... =u=Kw R
12、说明:日程安排提前五分钟提醒 qnJ50 VVW
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 99u/fk L
13、说明:一条sql 语句搞定数据库分页 zsVcXBz
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 XQ?fJWLU
14、说明:前10条记录 \GL*0NJ
select top 10 * form table1 where 范围 OxQYNi2
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) 6\n?48x}
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) % :/_ f
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 E!!
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(select a from tableA ) except (select a from tableB) except (select a from tableC) jO8X:j09A
17、说明:随机取出10条数据
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select top 10 * from tablename order by newid() Uw)=WImz[
18、说明:随机选择记录 CxDcY
select newid() Od{jt7 <j#
19、说明:删除重复记录 SkHYXe"]
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) {x{H$ f
20、说明:列出数据库里所有的表名 *5D3vB*S
select name from sysobjects where type='U' xE1'&!4O
21、说明:列出表里的所有的
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select name from syscolumns where id=object_id('TableName') n@
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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。 AnMV <
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 ?pG/m%[
显示结果: =45W\
type vender pcs :q
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电脑 A 1 ',)7GY/n~
电脑 A 1 g^l RG3a
光盘 B 2 Ur!~<4GO
光盘 A 2 d1]i,C~Y
手机 B 3 H0>yi[2f
手机 C 3 :( ,mL2[
23、说明:初始化表table1 6kR\xP]Kr
TRUNCATE TABLE table1 SK
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24、说明:选择从10到15的记录 #jA) >z\Q^
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 1e}8LH7
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三、技巧 C6jR=@42Q
1、1=1,1=2的使用,在SQL语句组合时用的较多 66\jV6eH7L
"where 1=1" 是表示选择全部 "where 1=2"全部不选, +Gh7^v|"
如: Y#HI;Y^RP
if @strWhere !='' 6B6vP%H#
begin |PP.<ce\-
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere gXy-Mpzp
end gU;&$
else ss
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begin cb$-6ZE/
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' vFQ,5n;fF
end vt1lR5
我们可以直接写成 !{Z~<Ky
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere LFf`K)q
2、收缩数据库 >jTp6tu,
--重建索引 h`Tz5% n
DBCC REINDEX 2SG$LIV 9Y
DBCC INDEXDEFRAG sKL:p3r
--收缩数据和日志 $,27pkwHeW
DBCC SHRINKDB Y;
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DBCC SHRINKFILE }6]0hWsN[
3、压缩数据库 wtH~-xSB|
dbcc shrinkdatabase(dbname) qCPmbg
4、转移数据库给新用户以已存在用户权限 %d;ezY '2
exec sp_change_users_login 'update_one','newname','oldname' yI3kvh
go BRv x[u
5、检查备份集 T
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RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ;\{`Ci\
6、修复数据库 f_=~H<j!
ALTER DATABASE [dvbbs] SET SINGLE_USER :iUF7P1I
GO k'3Wt*i
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK s'\$t
GO (gXN%rsY
ALTER DATABASE [dvbbs] SET MULTI_USER Vba.uKNjk
GO RU#F8O
7、日志清除 1/Zh^foG
SET NOCOUNT ON ,wAz^cK|
DECLARE @LogicalFileName sysname, j
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@MaxMinutes INT, sa&) #Z:
@NewSize INT bC6oqF'#
USE tablename -- 要操作的数据库名 9`B$V##-L
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 SA"8!soY3
@MaxMinutes = 10, -- Limit on time allowed to wrap log. D Ml?o:l
@NewSize = 1 -- 你想设定的日志文件的大小(M) >m6&bfy\q
-- Setup / initialize y 1\'(1
DECLARE @OriginalSize int &
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SELECT @OriginalSize = size =^;P#kX
FROM sysfiles `[fxyg:u
WHERE name = @LogicalFileName +-$Ko fnM
SELECT 'Original Size of ' + db_name() + ' LOG is ' + h6D^G5i
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + BS1Ap
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' y1f:?L-z
FROM sysfiles 1;F`c`0<
WHERE name = @LogicalFileName vVxD!EL
CREATE TABLE DummyTrans I]`-|Q E
(DummyColumn char (8000) not null) gVR@&bi7
DECLARE @Counter INT, v|';!p|
@StartTime DATETIME, qxOi>v0\H
@TruncLog VARCHAR(255) gl%`qf6:O
SELECT @StartTime = GETDATE(), B&?sF" Y
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' v6=-g$FG
DBCC SHRINKFILE (@LogicalFileName, @NewSize) R[B?C;+(O
EXEC (@TruncLog) EnVuD
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-- Wrap the log if necessary. PkuTg";
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired (5Nv8H8|
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) +0l`5."d
AND (@OriginalSize * 8 /1024) > @NewSize 9 ;i\g=
BEGIN -- Outer loop. Cb;WZ3HR
SELECT @Counter = 0 %;xOB^H^
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ~@W*r5/
BEGIN -- update p{$p
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INSERT DummyTrans VALUES ('Fill Log') F>hZ{
DELETE DummyTrans +-?/e-z")
SELECT @Counter = @Counter + 1 yYZxLJ='
END x.mrCJn)
EXEC (@TruncLog) u9qMqeF
END w n|]{Ww35
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ""iaGH+Cxw
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + Vr.Y/3N&'
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' zg)sd1@
FROM sysfiles x2Lq=zwJ
WHERE name = @LogicalFileName &HZmQ>!R D
DROP TABLE DummyTrans s%4M$e
SET NOCOUNT OFF RW'nUL?_\
8、说明:更改某个表 ]; $] G-
exec sp_changeobjectowner 'tablename','dbo' 5*g]qJF
9、存储更改全部表 Ah69
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CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch xg@NQI@7
@OldOwner as NVARCHAR(128), ),}AI/j;zY
@NewOwner as NVARCHAR(128) ?/hZb"6W
AS yR5XJ;Tct
DECLARE @Name as NVARCHAR(128) SkQswH
DECLARE @Owner as NVARCHAR(128) EbNd=Z'J
DECLARE @OwnerName as NVARCHAR(128) pc]J[ S?P
DECLARE curObject CURSOR FOR XRN+`J
select 'Name' = name, ^Q<mV*~
'Owner' = user_name(uid) W i.5Y{
from sysobjects t<iEj"5
where user_name(uid)=@OldOwner )FN;+"IJ
order by name KJn!Ap
OPEN curObject "_UdBG
FETCH NEXT FROM curObject INTO @Name, @Owner 0pb'\lA
WHILE(@@FETCH_STATUS=0) m7c*)"^
BEGIN QF2q^[>w6
if @Owner=@OldOwner CTa#Q,
begin .wA+S8}S
set @OwnerName = @OldOwner + '.' + rtrim(@Name) t&q N: J
exec sp_changeobjectowner @OwnerName, @NewOwner >4` dy
end SMr13%KN/
-- select @name,@NewOwner,@OldOwner n{0Ld -zH
FETCH NEXT FROM curObject INTO @Name, @Owner qFX~[h8i+
END U @v*0
close curObject PXoz*)tk
deallocate curObject :(|'S4z
GO Z6C=T;w
10、SQL SERVER中直接循环写入数据 @oP_;G
declare @i int #65^w=Sp}
set @i=1 ?
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while @i<30 /wShUR{
begin ~T7B$$
insert into test (userid) values(@i) WUc#)EEM)
set @i=@i+1 {~GYj%-^
end Rgy-OA
小记存储过程中经常用到的本周,本月,本年函数 f>o,N{|
Dateadd(wk,datediff(wk,0,getdate()),-1) ,QIF &
Dateadd(wk,datediff(wk,0,getdate()),6) [jdFA<Is
Dateadd(mm,datediff(mm,0,getdate()),0) INs!Ame2
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) e1myH6$W
Dateadd(yy,datediff(yy,0,getdate()),0) fc=Patg
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) gU^$Sx7'
上面的SQL代码只是一个时间段 -Y#sI3o*R8
Dateadd(wk,datediff(wk,0,getdate()),-1) @!N-RQ&A
Dateadd(wk,datediff(wk,0,getdate()),6) _ZB\L^j)
就是表示本周时间段. Gl %3XdU
下面的SQL的条件部分,就是查询时间段在本周范围内的: TcTM]ixr
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 9h90huyKF
而在存储过程中 #m{{a]zm^
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 8M*PML4r
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) WF&[HKOy/