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。 s7afj t
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一、基础 ,]:Gn5~
1、说明:创建数据库 &<x.D]FA]
CREATE DATABASE database-name
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2、说明:删除数据库 YA@MLZm
drop database dbname d<+hQ\BF,
3、说明:备份sql server w
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--- 创建 备份数据的 device /o%VjP"<
USE master obE8iG@H
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' }zks@7kf
--- 开始 备份 @R}3f6@67
BACKUP DATABASE pubs TO testBack |_+#&x
4、说明:创建新表 <#J5.I 1
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) OLPY<ax
根据已有的表创建新表: $[}EV(#y
A:create table tab_new like tab_old (使用旧表创建新表) PW|=IPS
B:create table tab_new as select col1,col2... from tab_old definition only k_{?{:X;y
5、说明:删除新表 Fsm6gE`|n
drop table tabname pU9.#O
6、说明:增加一个列 5RvE ),
Alter table tabname add column col type Q5ff&CE
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 ywl=@
7、说明:添加主键: Alter table tabname add primary key(col) O!%T<2i3
说明:删除主键: Alter table tabname drop primary key(col) rf-yUH]&S
8、说明:创建索引:create [unique] index idxname on tabname(col....) &&m3E=K!^
删除索引:drop index idxname /!2`pv
注:索引是不可更改的,想更改必须删除重新建。 H<[~V0=
9、说明:创建视图:create view viewname as select statement ]/kpEx
删除视图:drop view viewname i^e8.zgywF
10、说明:几个简单的基本的sql语句 F|{uA/P{
选择:select * from table1 where 范围 8q%y(e
插入:insert into table1(field1,field2) values(value1,value2) "!D y[J
删除:delete from table1 where 范围 F$(ak;v}
更新:update table1 set field1=value1 where 范围 r8@]|`j
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! g9q}D-
排序:select * from table1 order by field1,field2 [desc] O>pv/Ns
总数:select count as totalcount from table1 hVmnXT
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求和:select sum(field1) as sumvalue from table1 &oMWs]0
平均:select avg(field1) as avgvalue from table1 En1LGi4#
最大:select max(field1) as maxvalue from table1 u -P !2vT
最小:select min(field1) as minvalue from table1 RYA@{.O
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11、说明:几个高级查询运算词 z4:<?K
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A: UNION 运算符 k'PvTWR
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。 4")`}T
B: EXCEPT 运算符 H)i|?3Ip
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。 "5Y6.$Cuf!
C: INTERSECT 运算符 iX6>u4~(
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。 Vn4wk>b}$2
注:使用运算词的几个查询结果行必须是一致的。 :u./"[G
12、说明:使用外连接 7dcR@v`c
A、left outer join: *s*Y uY%y
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 \?>M?6D
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c IC&P-X_aP
B:right outer join: 'Zp{
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 i? ~-%
C:full outer join: Nwz?*~1
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 oR&z,%0wMK
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二、提升 nV7Vc;
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) o^vX\a?`u
法一:select * into b from a where 1<>1 E I zy
法二:select top 0 * into b from a .dk<?BI#H
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 7Vsp<s9bj
insert into b(a, b, c) select d,e,f from b; ]vlBYAW'
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) R`cP%7K
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 1'\QD`M9^
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. X0u,QSt'O
4、说明:子查询(表名1:a 表名2:b) q9_$&9
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) <kdlXS>J.
5、说明:显示文章、提交人和最后回复时间 3}<U'%sd
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b zk
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6、说明:外连接查询(表名1:a 表名2:b) dv>n38&mDQ
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c bO2?DszT5
7、说明:在线视图查询(表名1:a ) H#_Zv]
select * from (SELECT a,b,c FROM a) T where t.a > 1; Z;Hkx1
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 +q}t%K5
select * from table1 where time between time1 and time2 8^>c_%e}
select a,b,c, from table1 where a not between 数值1 and 数值2 ![^pAEgx
9、说明:in 的使用方法 IgG[Pr'D
select * from table1 where a [not] in ('值1','值2','值4','值6') bsF_.S*k@
10、说明:两张关联表,删除主表中已经在副表中没有的信息 7bzm5w@v
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) lb.Q^TghU
11、说明:四表联查问题: iCF},W+
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 ..... Y@0'0
12、说明:日程安排提前五分钟提醒 -3R:~z^L
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 e4YP$}_L
13、说明:一条sql 语句搞定数据库分页 QM F
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 WHY/x /$
14、说明:前10条记录 B={_}f
select top 10 * form table1 where 范围 Q2VF+g,
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.) m4 (pMrJ
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) n?.; *:
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 Dz: +.
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(select a from tableA ) except (select a from tableB) except (select a from tableC) &)mZ~cPU3
17、说明:随机取出10条数据 z~pp7
select top 10 * from tablename order by newid() V_gl#e#
18、说明:随机选择记录 x/umwT,o v
select newid() `y3'v]
19、说明:删除重复记录 yx5e
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) &.,K@OFE}
20、说明:列出数据库里所有的表名 zHb[.ry~
select name from sysobjects where type='U' s2{SbOBis
21、说明:列出表里的所有的 Ev5~= ]
select name from syscolumns where id=object_id('TableName') g0tnt)]
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。 ?`piie9V
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 |nZ^RCHog
显示结果: F'Y ad
type vender pcs P9bM+@5e
电脑 A 1 [34N/;5
电脑 A 1 #[#evlr=
光盘 B 2 ,Y/B49
光盘 A 2 AU$~Ap*rsa
手机 B 3 k{SGbC1=VK
手机 C 3 f1MRmp-f'
23、说明:初始化表table1 q@ -B+
TRUNCATE TABLE table1 P C_!
24、说明:选择从10到15的记录 'w+]kt-
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc {h?pvH_>
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三、技巧 ^HSxE
1、1=1,1=2的使用,在SQL语句组合时用的较多 7y'":1
"where 1=1" 是表示选择全部 "where 1=2"全部不选, R&Y_
如: _J
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if @strWhere !='' ]nhh|q9r{
begin @f-X/q]P
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ?bB>}:~j)
end \Fz9O-jb4
else hpAdoy[
begin 0>sa{Z
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 9GD0jJEu
end fwFJe(.
我们可以直接写成 xol%\$|
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere <k:I2LF_
2、收缩数据库 I\.|\^
--重建索引 5naFn m7%
DBCC REINDEX :<qe2Z5k
DBCC INDEXDEFRAG *,\"}x*
--收缩数据和日志 @V%\Gspv
DBCC SHRINKDB >!=@TK(~
DBCC SHRINKFILE c@t?R$c
3、压缩数据库 ^c\O,*:
dbcc shrinkdatabase(dbname) $+*nb4
4、转移数据库给新用户以已存在用户权限 |Kd#pYt%O
exec sp_change_users_login 'update_one','newname','oldname' ] 3{t}qY$A
go 5*YoK)2J
5、检查备份集 |p6d]#z3
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' aOzIo-
6、修复数据库 iS$[dC ?N
ALTER DATABASE [dvbbs] SET SINGLE_USER !=dz^f.{
GO G?W:O{n3
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK >v:ex(y0
GO ra$:ibLN
ALTER DATABASE [dvbbs] SET MULTI_USER FU3K?A
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GO .k,j64
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7、日志清除 (C!p2f
SET NOCOUNT ON V?u#WJy/
DECLARE @LogicalFileName sysname, aA`eKy) \
@MaxMinutes INT, J2=4%#R!
@NewSize INT l 00i2w
USE tablename -- 要操作的数据库名 GcVQz[E
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 ]8p{A#1
@MaxMinutes = 10, -- Limit on time allowed to wrap log. #fuUAbU0X
@NewSize = 1 -- 你想设定的日志文件的大小(M) v"G1vSx)BT
-- Setup / initialize iq; |
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DECLARE @OriginalSize int 75# 8P?i
SELECT @OriginalSize = size {D4FYr
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FROM sysfiles 6@N,'a8r
WHERE name = @LogicalFileName 0JlNUO5Nt
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 3( BL
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + X0.H(p#s
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' &6x(%o|
FROM sysfiles '}Fe&%
WHERE name = @LogicalFileName (T%F^s5D
CREATE TABLE DummyTrans pR
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(DummyColumn char (8000) not null) V:n0BlZ,B
DECLARE @Counter INT, a"vzC$Hxd
@StartTime DATETIME, Lw>B:3e
@TruncLog VARCHAR(255) [6!k:-t+
SELECT @StartTime = GETDATE(), $Rm~ VwY#
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' l/N<'T_G
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ZJ/528Ju
EXEC (@TruncLog) J>Ar(p
-- Wrap the log if necessary. /q9I^ ztV
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired A,~3oQV
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) B7%,D}
AND (@OriginalSize * 8 /1024) > @NewSize ,!:c6F+
BEGIN -- Outer loop. \*$^}8
SELECT @Counter = 0 $BwWQ?lp
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) hi8q?4jE
BEGIN -- update ;+ hh|NiQ
INSERT DummyTrans VALUES ('Fill Log') <o(;~
DELETE DummyTrans -<g9) CV5
SELECT @Counter = @Counter + 1 (p{X.X+
END )d3
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EXEC (@TruncLog) 0+>g/>
END `d_T3^ayu
SELECT 'Final Size of ' + db_name() + ' LOG is ' + T)! }Wvv
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + fCY|iO0.t
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' #w{`6}p
FROM sysfiles Px_8lB/;
WHERE name = @LogicalFileName gT)(RS`_)
DROP TABLE DummyTrans lJK]S=cd
SET NOCOUNT OFF tia}&9;
8、说明:更改某个表 ,P~e)<.
exec sp_changeobjectowner 'tablename','dbo' J}V4.R5d
9、存储更改全部表 aq?bI:>8
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch 9)!Ksg(h
@OldOwner as NVARCHAR(128), mA(kq
@NewOwner as NVARCHAR(128) 8SjCU+V
AS Id=20og
DECLARE @Name as NVARCHAR(128) YgEd%Z%4
DECLARE @Owner as NVARCHAR(128) /~"-q
DECLARE @OwnerName as NVARCHAR(128) v`S5[{6
DECLARE curObject CURSOR FOR i/X3k&
select 'Name' = name, k\OZ'dS
'Owner' = user_name(uid) xg p)G!
from sysobjects [+[W\6
where user_name(uid)=@OldOwner y_WC"
order by name <-`bWz=+
OPEN curObject ufL,Kq4
FETCH NEXT FROM curObject INTO @Name, @Owner \]x`f3F
WHILE(@@FETCH_STATUS=0) 3!P^?[p3
BEGIN 7F"ljkN1S
if @Owner=@OldOwner e9p/y8gC
begin : /5+p>Ep}
set @OwnerName = @OldOwner + '.' + rtrim(@Name) 8{4'G$6
exec sp_changeobjectowner @OwnerName, @NewOwner !@z9n\Yj
end
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-- select @name,@NewOwner,@OldOwner @fd<
FETCH NEXT FROM curObject INTO @Name, @Owner #aqnj+
END sUF$eVAT
close curObject h[(YH ;Y
deallocate curObject WAn@8!9
GO |r@;ulO
10、SQL SERVER中直接循环写入数据 O@$>'Z
declare @i int "@x(2(Y&
set @i=1 +wQ5m8E
while @i<30 WyV4p
begin r9f- [wC
insert into test (userid) values(@i) S]H[&o1o
set @i=@i+1 I"]E}n d)
end YdI6|o@vc
小记存储过程中经常用到的本周,本月,本年函数 m-{DhJV
Dateadd(wk,datediff(wk,0,getdate()),-1) NZGO8u
Dateadd(wk,datediff(wk,0,getdate()),6) gc4o
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Dateadd(mm,datediff(mm,0,getdate()),0) L91(|gQP
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) HG7Qdw2+O
Dateadd(yy,datediff(yy,0,getdate()),0) ~D5
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Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) }-[l)<F:
上面的SQL代码只是一个时间段 0hS&4nW
Dateadd(wk,datediff(wk,0,getdate()),-1) IR/S`HD_
Dateadd(wk,datediff(wk,0,getdate()),6) k7Nx#%xx
就是表示本周时间段. oypLE=H
下面的SQL的条件部分,就是查询时间段在本周范围内的: LsR<r1KDJ
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 2[w9#6ly
而在存储过程中 H [+'>Id:
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) <(E)M@2
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) uz8eS'8