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。 PR5N:Bw
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一、基础 tC|?Kl7
1、说明:创建数据库 ~*bfS}F8I
CREATE DATABASE database-name PP{9Y Vr
2、说明:删除数据库 z'l
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drop database dbname JXL?.{'A
3、说明:备份sql server MrzD
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--- 创建 备份数据的 device Tr_gc~
USE master T#Q7L~?zY
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' M~\dvJ$cH
--- 开始 备份 2*Qi4%s#
BACKUP DATABASE pubs TO testBack @\nQ{\^;
4、说明:创建新表 W:8MqVm34
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) `E1G9BbU
根据已有的表创建新表:
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A:create table tab_new like tab_old (使用旧表创建新表) vYm-$KQ"o
B:create table tab_new as select col1,col2... from tab_old definition only 0 aH&M4
5、说明:删除新表 N `:MF 9
drop table tabname C W#:'
6、说明:增加一个列 .O"a: ^i
Alter table tabname add column col type
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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。 &(,\~
7、说明:添加主键: Alter table tabname add primary key(col) .KKecdd?=
说明:删除主键: Alter table tabname drop primary key(col) C]2-V1,ZX
8、说明:创建索引:create [unique] index idxname on tabname(col....) iO?AY
删除索引:drop index idxname t3<8n;'y:
注:索引是不可更改的,想更改必须删除重新建。 /%g9g_rt#
9、说明:创建视图:create view viewname as select statement M>Q ZN
删除视图:drop view viewname .Pj<Pe
10、说明:几个简单的基本的sql语句 keLeD1
选择:select * from table1 where 范围 27fLW&b2
插入:insert into table1(field1,field2) values(value1,value2) qdI%v#'M
删除:delete from table1 where 范围 P}~MO)*1
更新:update table1 set field1=value1 where 范围 l#enbQ`-~
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! `$Rgn3
排序:select * from table1 order by field1,field2 [desc] 5c3-?u!
总数:select count as totalcount from table1 xjr4')h
求和:select sum(field1) as sumvalue from table1 d eT<)'"
平均:select avg(field1) as avgvalue from table1 vY_[@y
最大:select max(field1) as maxvalue from table1 :=y5713
最小:select min(field1) as minvalue from table1 KGM__Z O.
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11、说明:几个高级查询运算词 W9]z]6
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A: UNION 运算符 d~qQ_2M[G
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 1l$C3c
B: EXCEPT 运算符 E>s+"y
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。 7tlK'j'
C: INTERSECT 运算符 " Bx@(
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。 qZ^
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注:使用运算词的几个查询结果行必须是一致的。 "jyo'r
12、说明:使用外连接 PolJo?HZ
A、left outer join: y#B=9Ri=z
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。 KV$&qM.
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c x 4_MbUe
B:right outer join: ':pDlUA
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 nQmHYOF%
C:full outer join: RJ@79L*#
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 n5kGHL2
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二、提升 ]6B9\C.2-_
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) %3qjgyLZ|
法一:select * into b from a where 1<>1 u!|_bI3
法二:select top 0 * into b from a IOZw[9](+
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 5zBA ]1PY
insert into b(a, b, c) select d,e,f from b; /al56n
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 7JBs7LG
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 7FoX)54"
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. >
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4、说明:子查询(表名1:a 表名2:b) `{!A1xKZ
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) V8 8u-
5、说明:显示文章、提交人和最后回复时间 Y"bm4&'
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b g@^ y$wt
6、说明:外连接查询(表名1:a 表名2:b) ru 6`Z+p
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c "O>~osj
7、说明:在线视图查询(表名1:a ) z)hK 2JD
select * from (SELECT a,b,c FROM a) T where t.a > 1; _C5i\Y)
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 MS;^:t1`
select * from table1 where time between time1 and time2 AVQcD`V3B
select a,b,c, from table1 where a not between 数值1 and 数值2 tcj"rV{G
9、说明:in 的使用方法 w{DU<e:
select * from table1 where a [not] in ('值1','值2','值4','值6') b\ED<'
10、说明:两张关联表,删除主表中已经在副表中没有的信息 8<;.
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) T+Re1sPr?
11、说明:四表联查问题: P?V+<c{
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 ..... zNX=V!$
12、说明:日程安排提前五分钟提醒 #6\mTL4vg
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 'S6zk wC]
13、说明:一条sql 语句搞定数据库分页 Pr}
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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 B0b|+5WhR
14、说明:前10条记录 e=VSO!(rY
select top 10 * form table1 where 范围 >I@&"&d
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.) aQmS'{d?^
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) D Z*c.|W
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 mH$ `)i8
(select a from tableA ) except (select a from tableB) except (select a from tableC) LAc60^t1
17、说明:随机取出10条数据 Se!w(Y&
select top 10 * from tablename order by newid() @xdtl{5G
18、说明:随机选择记录 RjVUm+<
select newid() ^Ak?2,xB#+
19、说明:删除重复记录 #9(+)~irz`
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) .>;??BG}
20、说明:列出数据库里所有的表名 t+A*Ws*o
select name from sysobjects where type='U' 0"e["q{|
21、说明:列出表里的所有的 DtBvfYO8)>
select name from syscolumns where id=object_id('TableName')
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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。 #L!`n)J"
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 ,K}"o~z
显示结果: /F.<Gz;w
type vender pcs t"Du
电脑 A 1 -_9*BvS]R
电脑 A 1 >uZc#Zt
光盘 B 2 @:w^j0+h
光盘 A 2 %m6qL
手机 B 3 cu1!WD
手机 C 3 p,z>:3M
23、说明:初始化表table1 DC).p'0VL
TRUNCATE TABLE table1 4PD5i
24、说明:选择从10到15的记录 -l}"DP
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select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc yH:p*|% :
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三、技巧 ,k.")
1、1=1,1=2的使用,在SQL语句组合时用的较多 uDG>m7(}/h
"where 1=1" 是表示选择全部 "where 1=2"全部不选, rhOxyY0
如: KJ/Gv#Kj
if @strWhere !='' }#.OJub
begin eptw)S-j
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere |a])o
end x Y$x=)
else 7>zUT0SS
begin T*B`8P
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' SD~4CtlfI
end bO$KV"*!
我们可以直接写成 +Goh`!$Rj9
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere J0bcW25
2、收缩数据库 F&p42!"
--重建索引 A]QGaWK
DBCC REINDEX ,b^jAzow
DBCC INDEXDEFRAG yo_zc<
--收缩数据和日志 g@O?0,+1
DBCC SHRINKDB |2TH[J_a
DBCC SHRINKFILE {pXX%>
3、压缩数据库 (i{ZxWW&
dbcc shrinkdatabase(dbname) >G?*rg4
4、转移数据库给新用户以已存在用户权限 I^LU*A=
exec sp_change_users_login 'update_one','newname','oldname' =saRh)EM
go /w6'tut
5、检查备份集 .+8#&Uy
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' evE:FiDm(j
6、修复数据库 F{ 4k2Izr
ALTER DATABASE [dvbbs] SET SINGLE_USER t#f-3zd9
GO u9q#L.Ij
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK (O:&RAkk7
GO ~_CZ1
ALTER DATABASE [dvbbs] SET MULTI_USER " 5Pqvi
GO b:O_PS5h
7、日志清除 'SE5sB
SET NOCOUNT ON {J)gS
DECLARE @LogicalFileName sysname, u1'l4VgT
@MaxMinutes INT, I+Qt5Ox
@NewSize INT +sZY0(|K8
USE tablename -- 要操作的数据库名 %Y.@AiViz
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 'g<FL`iP
@MaxMinutes = 10, -- Limit on time allowed to wrap log. btC<>(kl&
@NewSize = 1 -- 你想设定的日志文件的大小(M) `}
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-- Setup / initialize z6qx9x|Ij
DECLARE @OriginalSize int &F0>V o
SELECT @OriginalSize = size ^=-W8aVi>
FROM sysfiles +:C.G[+
WHERE name = @LogicalFileName *g'%5i1ed
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 2xy{g&G
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + N-<,wUxf
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' %gqu7}'
FROM sysfiles ~2Mcw`<
WHERE name = @LogicalFileName s<C66z
CREATE TABLE DummyTrans hR[_1vuIu
(DummyColumn char (8000) not null) `ST;";7!
DECLARE @Counter INT, cE,,9M@^
@StartTime DATETIME, >6(e6/C-9
@TruncLog VARCHAR(255) Rh@UxNy\,
SELECT @StartTime = GETDATE(), iqd7
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' l@<Jp *|
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 7bM
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EXEC (@TruncLog) Y$hLsM\%
-- Wrap the log if necessary. Q^lgtb
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired W H+Sd
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) %yVP@M
AND (@OriginalSize * 8 /1024) > @NewSize Co<F<eXe
BEGIN -- Outer loop. XPi5E"
SELECT @Counter = 0 Ao9=TC'v$'
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) `GooSX
BEGIN -- update $L]E<
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INSERT DummyTrans VALUES ('Fill Log') 'Hq#9?<2M
DELETE DummyTrans }"^d<dvuz
SELECT @Counter = @Counter + 1 S }G3h a
END fdKTj
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EXEC (@TruncLog) eGrxS;NY
END @7Nc*-SM
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 4Z{ r
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + wqQrby<
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' LgSVEQb6\|
FROM sysfiles R|7_iMIZ
WHERE name = @LogicalFileName XXW.Uios
DROP TABLE DummyTrans Ymcc|u6 $"
SET NOCOUNT OFF iS8yJRy
8、说明:更改某个表 &,=t2_n
exec sp_changeobjectowner 'tablename','dbo' 6~8X/
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9、存储更改全部表 K./L'Me
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch J#k.!]r,Y
@OldOwner as NVARCHAR(128), IqjH
@NewOwner as NVARCHAR(128) =/^{Pn
AS hL/
DECLARE @Name as NVARCHAR(128) V7Mp<x%
DECLARE @Owner as NVARCHAR(128) Dj{t[z]$k
DECLARE @OwnerName as NVARCHAR(128) ].*I Z
DECLARE curObject CURSOR FOR bdyE9t
select 'Name' = name, nc>Ae`"(
'Owner' = user_name(uid) v0~*?m4
from sysobjects rWzO>v
where user_name(uid)=@OldOwner
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order by name -*"Q-GO
OPEN curObject [yfi:|n1
FETCH NEXT FROM curObject INTO @Name, @Owner Z=/bD*\g
WHILE(@@FETCH_STATUS=0) IqmQQ_KH
BEGIN Eh?,-!SUQn
if @Owner=@OldOwner f5|Ew&1EP
begin 8#~x6\!b
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 4>8'.8S
exec sp_changeobjectowner @OwnerName, @NewOwner MF~Tr0tOC
end w}QU;rl8q
-- select @name,@NewOwner,@OldOwner gJI(d6
FETCH NEXT FROM curObject INTO @Name, @Owner "( P-VX
END g:>Mooxzi
close curObject r081.<
deallocate curObject `!iVMTp
GO Wfyap)y
10、SQL SERVER中直接循环写入数据 IgU65p
declare @i int x 3?:"D2
set @i=1 B[6y2+6$0
while @i<30 Rd{#cW~
begin )o@-h85";
insert into test (userid) values(@i) mg7Q~SLL{
set @i=@i+1 (GJW3
end s+yX82Y
小记存储过程中经常用到的本周,本月,本年函数 /MQI5Djg
Dateadd(wk,datediff(wk,0,getdate()),-1) ZSg["`
Dateadd(wk,datediff(wk,0,getdate()),6) Yv [j5\:x
Dateadd(mm,datediff(mm,0,getdate()),0) Yy:Q/zwo
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ]f"l4ay@M
Dateadd(yy,datediff(yy,0,getdate()),0) wst)O{ 4
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) %4rPkPAtrp
上面的SQL代码只是一个时间段 w-.=u3
Dateadd(wk,datediff(wk,0,getdate()),-1) @`6db
Dateadd(wk,datediff(wk,0,getdate()),6) R@)L@M)u;
就是表示本周时间段. #=B~}
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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: /_G^d1T1?L
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) hhVyz{u
而在存储过程中 e)2s2y@zi
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 5U^
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) Nn;p1n
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