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。 f0&%
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一、基础 4-m6e$p;
1、说明:创建数据库 OE*Y%*b
CREATE DATABASE database-name zf;sdQ;4
2、说明:删除数据库 '^)}"sZ@G
drop database dbname U0U y
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3、说明:备份sql server EKus0"|
--- 创建 备份数据的 device ^B:;uyG]M
USE master VwOcWKD
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' JED\"(d(
--- 开始 备份 < 1[K1'7h
BACKUP DATABASE pubs TO testBack sGa}Cf;H@g
4、说明:创建新表 Ad&VOh+0
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) $[UUf}7L
根据已有的表创建新表: wJj:hA}
A:create table tab_new like tab_old (使用旧表创建新表) p(6 sN=
B:create table tab_new as select col1,col2... from tab_old definition only P ; h8
5、说明:删除新表 ?N^1v&Q
drop table tabname ?4^ 0xGyE
6、说明:增加一个列 +z4E:v
Alter table tabname add column col type &`oybm-p(
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 TV=K3F5)M
7、说明:添加主键: Alter table tabname add primary key(col) McpQ7\*h
说明:删除主键: Alter table tabname drop primary key(col) ocu,qL)W
8、说明:创建索引:create [unique] index idxname on tabname(col....) m?kyAW'|
删除索引:drop index idxname Dxy^r*B
注:索引是不可更改的,想更改必须删除重新建。 k%BU&%?1
9、说明:创建视图:create view viewname as select statement 2VzYP~Jg
删除视图:drop view viewname 2+_a<5l~
10、说明:几个简单的基本的sql语句 ,l Y4WO
选择:select * from table1 where 范围 Xv3pKf-K
插入:insert into table1(field1,field2) values(value1,value2) 2RQ-L
删除:delete from table1 where 范围 PV:J>!]
更新:update table1 set field1=value1 where 范围 >n^780S|
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! T*nP-b
排序:select * from table1 order by field1,field2 [desc] zz
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总数:select count as totalcount from table1 3)yL#hXg)
求和:select sum(field1) as sumvalue from table1 xHMFYt+0$G
平均:select avg(field1) as avgvalue from table1 l0C`teO
最大:select max(field1) as maxvalue from table1 SL-;h#-y
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最小:select min(field1) as minvalue from table1 PD&gC88
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11、说明:几个高级查询运算词 @S=9@3m{w;
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A: UNION 运算符 w@<II-9L)<
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。 ]IE Z?+F,
B: EXCEPT 运算符 C!|LGzs0
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。 z;!"i~fFK
C: INTERSECT 运算符 rtfRA<
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。 2,wwI<=E'
注:使用运算词的几个查询结果行必须是一致的。 em'ADRxG+
12、说明:使用外连接 <Se9aD
A、left outer join: \5 rJ
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。 M~N/er
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 SnR2o3r-Of
B:right outer join: U(#JC(E-#
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。 iGkysU<wcp
C:full outer join: le]~Cy0
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 x4GP2
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二、提升 ^sB0$|DU
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 3H`{
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法一:select * into b from a where 1<>1 vENf3;o0
法二:select top 0 * into b from a mf)+ 5On
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 1I{8 |
insert into b(a, b, c) select d,e,f from b; "i\#L`TkzX
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) A&bj l[s
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 a]T&-#c,}
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. -rn6ZSD)
4、说明:子查询(表名1:a 表名2:b) 'It8h$^j
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) @0 /qP<E
5、说明:显示文章、提交人和最后回复时间
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select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b A4cOnG,
6、说明:外连接查询(表名1:a 表名2:b) HA*L*:0
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c ,T`,OZm
7、说明:在线视图查询(表名1:a ) y?3.W
select * from (SELECT a,b,c FROM a) T where t.a > 1; ,|B-Nq
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 H#DvCw
select * from table1 where time between time1 and time2 8'HS$J;C
select a,b,c, from table1 where a not between 数值1 and 数值2 {eV8h}KIl
9、说明:in 的使用方法 q;")
select * from table1 where a [not] in ('值1','值2','值4','值6') uINdeq 7|F
10、说明:两张关联表,删除主表中已经在副表中没有的信息 0'fswa)
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) XS">`9o!
11、说明:四表联查问题: ".tL+A[
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... Ff%V1BH[
12、说明:日程安排提前五分钟提醒 -X~mW
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 Cf3!Ud
13、说明:一条sql 语句搞定数据库分页 qS2Nk.e]o
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 Z sTtSM\Ac
14、说明:前10条记录
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select top 10 * form table1 where 范围 z8'1R6nq
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) M{Z
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select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) m$kQbPlatN
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 %KXiB6<4
(select a from tableA ) except (select a from tableB) except (select a from tableC) X
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17、说明:随机取出10条数据 >
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select top 10 * from tablename order by newid() 6e B;
18、说明:随机选择记录 n+Kv^Y`qxO
select newid() iBd6&?E?<
19、说明:删除重复记录 %^pi
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) XS [L-NHG
20、说明:列出数据库里所有的表名 Ch_rV+
select name from sysobjects where type='U' $KO2+^%y
21、说明:列出表里的所有的 LWN{
select name from syscolumns where id=object_id('TableName') jb-kg</A
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 67YC;J]n=z
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type o^\Pt<~W
显示结果: 0(D^NtB7
type vender pcs /v8Q17O?e
电脑 A 1 YR9fw
电脑 A 1 eZLEdTScM
光盘 B 2 UtQey ;w
光盘 A 2
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手机 B 3 >sfg`4
手机 C 3 >H!Mx_fDL
23、说明:初始化表table1 )rD!4"8/A
TRUNCATE TABLE table1 x8PT+KC
24、说明:选择从10到15的记录 r8J 7zTD&
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc #Ub_m@@4
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三、技巧 UJ)pae
1、1=1,1=2的使用,在SQL语句组合时用的较多 _`|1B$@x
"where 1=1" 是表示选择全部 "where 1=2"全部不选, d]pb1ECuu
如: '7-Yo
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if @strWhere !='' %w*)7@,+-
begin //U1mDFT
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ?)xIn)#ls
end h_vTA
else w +t@G`d
begin hfaU-IPcFX
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' `}}:9d
end :"\,iH
我们可以直接写成 \^c4v\s<o#
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere wZiUzS;v
2、收缩数据库 :$MOdL[ir
--重建索引 GiV%Hcx
DBCC REINDEX zTF{ g+
DBCC INDEXDEFRAG O?JJE8~']
--收缩数据和日志 NXU:b"G
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DBCC SHRINKDB 3/kT'r
DBCC SHRINKFILE }}JMwT
3、压缩数据库 =?<WCR
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dbcc shrinkdatabase(dbname) `Vb
4、转移数据库给新用户以已存在用户权限 ]:<!(
exec sp_change_users_login 'update_one','newname','oldname' h[ DNhR
go T{k
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5、检查备份集 cz>,sz~i
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' z-5`6aE9<
6、修复数据库 tnRf!A;m
ALTER DATABASE [dvbbs] SET SINGLE_USER oJz2-PmX
GO n|w+08c"
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 3!"N;Q"
GO 9\?OV@
ALTER DATABASE [dvbbs] SET MULTI_USER B `~EA] d
GO ^Xk!wJ
7、日志清除 I&;>(@K
SET NOCOUNT ON P[nc8z[
DECLARE @LogicalFileName sysname, ~[g(@Xt
@MaxMinutes INT, 21uK&nVf^l
@NewSize INT ~s!Q0G^G
USE tablename -- 要操作的数据库名 a1U|eLmUb
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 M"~jNe|
@MaxMinutes = 10, -- Limit on time allowed to wrap log. /4:bx#;A
@NewSize = 1 -- 你想设定的日志文件的大小(M) 1i76u!{U
-- Setup / initialize _ E;T"SC
DECLARE @OriginalSize int Zv u6/#
SELECT @OriginalSize = size Z/#_Swv
FROM sysfiles w,LtQhQ
WHERE name = @LogicalFileName m1"m KM
SELECT 'Original Size of ' + db_name() + ' LOG is ' + O
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CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + :
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CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' Q`ua9oIJ=
FROM sysfiles 5)k8(kH
WHERE name = @LogicalFileName (#Y~z',I
CREATE TABLE DummyTrans Bt+^H6cb
(DummyColumn char (8000) not null) QU"WpkO
DECLARE @Counter INT, "yn~axk7
@StartTime DATETIME, x84!/n^z
@TruncLog VARCHAR(255) RLmOg{L
SELECT @StartTime = GETDATE(), AjC:E+g
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' "TV'}HH
DBCC SHRINKFILE (@LogicalFileName, @NewSize) )pB#7aEw
EXEC (@TruncLog) /WrB>w
-- Wrap the log if necessary. 51#*8u+L
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired IGdiIhH~2
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 9BCW2@Kp
AND (@OriginalSize * 8 /1024) > @NewSize Hq3|>OqC2Q
BEGIN -- Outer loop. 067c/c
SELECT @Counter = 0 DD|0?i
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) '%N?r,x
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BEGIN -- update 7FB?t<x
INSERT DummyTrans VALUES ('Fill Log') /F*Y~>*% 1
DELETE DummyTrans <Vat@e
SELECT @Counter = @Counter + 1 wu41Mz7
END |.<_$[v[x
EXEC (@TruncLog) +>ju,;4WK
END D31X {dJ
SELECT 'Final Size of ' + db_name() + ' LOG is ' + wj)LOA0
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + &qv~)ZM$
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' %pC<T*f
FROM sysfiles %b6$N_M{H1
WHERE name = @LogicalFileName 4>JSZ6i#n
DROP TABLE DummyTrans 3uL
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SET NOCOUNT OFF &,X}M
8、说明:更改某个表
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exec sp_changeobjectowner 'tablename','dbo' u?osX;'w
9、存储更改全部表 nzq
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch nL@'??I1
@OldOwner as NVARCHAR(128), 5{c;I<0
@NewOwner as NVARCHAR(128) AjzTszByu
AS |;ztK[(
DECLARE @Name as NVARCHAR(128) c4JV~VS+
DECLARE @Owner as NVARCHAR(128) j-<]OOD
DECLARE @OwnerName as NVARCHAR(128) j3j?2#vR
DECLARE curObject CURSOR FOR ]l,BUf-O
select 'Name' = name, vygzL U^
'Owner' = user_name(uid) ' \JE>#
from sysobjects ]#tB[G
where user_name(uid)=@OldOwner !3Q0Ahf
order by name Y.^L^ "%dF
OPEN curObject p|>*M\LE#
FETCH NEXT FROM curObject INTO @Name, @Owner +8Xjk\Hi
WHILE(@@FETCH_STATUS=0) 8-Abg:)
BEGIN tKbxC>w
if @Owner=@OldOwner 7]=&Q4e4
begin #'L<7t
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set @OwnerName = @OldOwner + '.' + rtrim(@Name) i8iT}^
exec sp_changeobjectowner @OwnerName, @NewOwner x|H`%Z
end bA;OphO(
-- select @name,@NewOwner,@OldOwner a:FU- ^B4~
FETCH NEXT FROM curObject INTO @Name, @Owner O-?rFNavxp
END bI):-2&s}
close curObject qmS9*me
{
deallocate curObject mF4W4~"
GO 5ggyk0
10、SQL SERVER中直接循环写入数据 |v&)O)Jg
declare @i int Xs03..S
set @i=1 Tz
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while @i<30 ``MO5${
begin K'A+V
insert into test (userid) values(@i) lriezI
set @i=@i+1 |9*Rnm_
end ~7m`p3W@
小记存储过程中经常用到的本周,本月,本年函数 ?<?Ogq"<
Dateadd(wk,datediff(wk,0,getdate()),-1) c%&,(NJ]K
Dateadd(wk,datediff(wk,0,getdate()),6) m#"_x{oa
Dateadd(mm,datediff(mm,0,getdate()),0) v%tjZ5x
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) -&+:7t
Dateadd(yy,datediff(yy,0,getdate()),0) _4{0He`q
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 73Dxf -
上面的SQL代码只是一个时间段 !:{Qbv&T
Dateadd(wk,datediff(wk,0,getdate()),-1) {K^5q{u
Dateadd(wk,datediff(wk,0,getdate()),6) bz*@[NQ
就是表示本周时间段. 'L /)9.29
下面的SQL的条件部分,就是查询时间段在本周范围内的: _3/u#'m0
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) L&\W+k
而在存储过程中 ym;]3<I?I[
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) l*CulVX
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) G[64qhTC