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。 j#VR>0oC]\
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一、基础 +5Y;JL<%/
1、说明:创建数据库 >+[{m<Eq
CREATE DATABASE database-name %W2
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2、说明:删除数据库 j W-K
drop database dbname clT[?8*
3、说明:备份sql server HNX/#?3
--- 创建 备份数据的 device
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USE master - l0X]&Ex
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' <Um 5w1
--- 开始 备份 cw~-%%/
BACKUP DATABASE pubs TO testBack #<w2xR]:
4、说明:创建新表 dhr-tw
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) llpgi,-=
根据已有的表创建新表: r)dXcus
A:create table tab_new like tab_old (使用旧表创建新表) T'14OU2N{Y
B:create table tab_new as select col1,col2... from tab_old definition only (6)X Fp&
5、说明:删除新表 o<Rrr,
drop table tabname XE:bYzH
6、说明:增加一个列 j|r$!gV
Alter table tabname add column col type '81WogH:
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 _E^ !,Wz
7、说明:添加主键: Alter table tabname add primary key(col) *Y ?&N2@c
说明:删除主键: Alter table tabname drop primary key(col) x{VUl
8、说明:创建索引:create [unique] index idxname on tabname(col....) %cq8%RT
删除索引:drop index idxname 5pxw[c53#
注:索引是不可更改的,想更改必须删除重新建。 RWGAxq`9f
9、说明:创建视图:create view viewname as select statement 2&<&q J
删除视图:drop view viewname 6?l|MU"Q.
10、说明:几个简单的基本的sql语句 ~:UAL}b{\~
选择:select * from table1 where 范围 Rap_1o9#\
插入:insert into table1(field1,field2) values(value1,value2) <'P+2(Oi
删除:delete from table1 where 范围 Ke\FzZ]
更新:update table1 set field1=value1 where 范围 HhUk9 >7
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ^F+7@*u
排序:select * from table1 order by field1,field2 [desc] t)l^$j!h@
总数:select count as totalcount from table1 chU,));F
求和:select sum(field1) as sumvalue from table1 3hR3)(+1
平均:select avg(field1) as avgvalue from table1 o{MmW~/o&
最大:select max(field1) as maxvalue from table1 g+ cH
最小:select min(field1) as minvalue from table1 J['?ud}@
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11、说明:几个高级查询运算词 r
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A: UNION 运算符 a+`;:tX,
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。 F#l!LER^1g
B: EXCEPT 运算符 1lHBg
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[bZg9;
C: INTERSECT 运算符 V_H0z
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。 frbeCBP&)
注:使用运算词的几个查询结果行必须是一致的。 k{+Gv}Y
12、说明:使用外连接 5G WC
A、left outer join: D{iPsH6};5
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。 wB%;O `Oh
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 ;-{'d8
B:right outer join:
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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。 !u%XvxJwDb
C:full outer join: I!g+K
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。 O['5/:-
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二、提升
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1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) /cZ-+cu
法一:select * into b from a where 1<>1 Wg=4`&F^
法二:select top 0 * into b from a
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) LhtA]z,m
insert into b(a, b, c) select d,e,f from b; G\H |\i
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) U$6(@&P!
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 >Te h ?P
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. [kPF J f
4、说明:子查询(表名1:a 表名2:b) 2[Bw+<YA`
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) |&0Cuwt
5、说明:显示文章、提交人和最后回复时间 #9@UzfZAwT
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b - f%J_`
6、说明:外连接查询(表名1:a 表名2:b) b:6e2|xf?
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Ve|=<7%%S
7、说明:在线视图查询(表名1:a ) ,Zs*07!$f
select * from (SELECT a,b,c FROM a) T where t.a > 1; 4k=LVu]Kcr
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 43o!Vr/S
select * from table1 where time between time1 and time2 Gq;!g(
select a,b,c, from table1 where a not between 数值1 and 数值2 tp3
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9、说明:in 的使用方法 $or8z2d1
select * from table1 where a [not] in ('值1','值2','值4','值6') 9{n?Jy
10、说明:两张关联表,删除主表中已经在副表中没有的信息 |Ht~o(]&&/
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) A&qZ:&(OM
11、说明:四表联查问题: !wEz=
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select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... {~~'
12、说明:日程安排提前五分钟提醒 `:;fc
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 vI+X9C?
13、说明:一条sql 语句搞定数据库分页 sn:wLc/GAd
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 4lF?s\W:
14、说明:前10条记录 #P-T4R
select top 10 * form table1 where 范围 |C.[eHe&D
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) APL #-`XC
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) "| KD$CY
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 DzG$\%G2R}
(select a from tableA ) except (select a from tableB) except (select a from tableC) \kVi&X=q:
17、说明:随机取出10条数据 9i/VvW
select top 10 * from tablename order by newid() 2/#%^,Kb2
18、说明:随机选择记录 g.eMGwonTJ
select newid() C!S(!Z,
19、说明:删除重复记录 _6{XqvWqb
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) {x/)S*:Z
20、说明:列出数据库里所有的表名 J+0T8
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select name from sysobjects where type='U' $ 2PpG|q
21、说明:列出表里的所有的 !6DH6<HC
select name from syscolumns where id=object_id('TableName') fs%l j_t
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。 )w&k&TY4H
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 R{SN.% {;
显示结果: C(lGW,!
type vender pcs "}jv5j5
电脑 A 1 lc\f6J>HT
电脑 A 1 "*0h=x$
光盘 B 2 _t;Mi/\P
光盘 A 2 "gGv>]3
手机 B 3 eUm,=s
手机 C 3 /&g~*AL
23、说明:初始化表table1 ]R8JBnA
TRUNCATE TABLE table1 rQ287y{
24、说明:选择从10到15的记录 8d*W7>rq
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc jp P'{mc
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三、技巧 3eJ"7sftW
1、1=1,1=2的使用,在SQL语句组合时用的较多 .]H1uoci|
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 2vx1M6a)L
如: ! )PV-[2
if @strWhere !=''
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begin I\:(`)"r
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere LKe~
end t{RdqAF
else 8:)itYE
begin eJtfQ@?
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' !w=6>B^
end x#,nR]C
我们可以直接写成 "qv J-Y
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere hTK6N
2、收缩数据库 M|uWSG
--重建索引 /$?7L(
DBCC REINDEX %:hU:+G E
DBCC INDEXDEFRAG v\b@;H`
--收缩数据和日志 ,T\)%q
DBCC SHRINKDB 0z:BSdno
DBCC SHRINKFILE mnS F=l;;
3、压缩数据库 c6Z\ecH9
dbcc shrinkdatabase(dbname) m(?ZNtBQt
4、转移数据库给新用户以已存在用户权限 /5 6sPl
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exec sp_change_users_login 'update_one','newname','oldname' >pq= .)X}
go <\C/;
5、检查备份集 Or*e$uMIY
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' 0)T`&u3!
6、修复数据库 -P7JaH/Q
ALTER DATABASE [dvbbs] SET SINGLE_USER 25CO_
GO hj|P*yKV
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK sJq^>"|J
GO RbGq$vYol/
ALTER DATABASE [dvbbs] SET MULTI_USER JVk"M=c
GO -cW'g
7、日志清除 =`%"-A
SET NOCOUNT ON [W{WfJ-HwG
DECLARE @LogicalFileName sysname, !<I3^q
@MaxMinutes INT, S@PAtB5
@NewSize INT "J(W)\
USE tablename -- 要操作的数据库名 UOAL7
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 6e.?L
@MaxMinutes = 10, -- Limit on time allowed to wrap log. BmGY#D,
@NewSize = 1 -- 你想设定的日志文件的大小(M) +9d]([Lx
-- Setup / initialize Y] "_}
DECLARE @OriginalSize int |'" 17c&
SELECT @OriginalSize = size @ATJ|5.gr
FROM sysfiles )`B
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WHERE name = @LogicalFileName uy^vQ/
SELECT 'Original Size of ' + db_name() + ' LOG is ' + Q1?09
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + b9gezXAcd
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' +IpC
FROM sysfiles 6 (@U+`
WHERE name = @LogicalFileName FG[YH5
CREATE TABLE DummyTrans w;Jby
(DummyColumn char (8000) not null) .*zWm
DECLARE @Counter INT, ]-b`uYb
@StartTime DATETIME, Q7vTTn\
@TruncLog VARCHAR(255) X[{tD#
SELECT @StartTime = GETDATE(), cun&'JOH?U
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 7@*l2edXm+
DBCC SHRINKFILE (@LogicalFileName, @NewSize) /degBL+
EXEC (@TruncLog) UZ` <D/
-- Wrap the log if necessary. +^\TG>le
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired .3JLa8y
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) t'pY~a9F
AND (@OriginalSize * 8 /1024) > @NewSize ]&mN~$+C
BEGIN -- Outer loop. Fw!TTH6l0
SELECT @Counter = 0 6*]g~)7`Q~
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) q;<=MO/
BEGIN -- update SlRQi:
INSERT DummyTrans VALUES ('Fill Log') cB ,l=/?
DELETE DummyTrans vm
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SELECT @Counter = @Counter + 1 2GRdfX
END qB0F9[U
EXEC (@TruncLog) B<p -.tv
END bXw!fYm&
SELECT 'Final Size of ' + db_name() + ' LOG is ' + [~[)C]-=
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + QSxR@hC
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 3w-0IP]<
FROM sysfiles $V0G[!4
WHERE name = @LogicalFileName 6pCQP
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DROP TABLE DummyTrans tin5.N)"z
SET NOCOUNT OFF |)vC^=N{+
8、说明:更改某个表 2sryhS'(H
exec sp_changeobjectowner 'tablename','dbo' iE;D_m.>`O
9、存储更改全部表 d@ ?++z
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch v.Y?<=E+<d
@OldOwner as NVARCHAR(128), ~;#OQ[
@NewOwner as NVARCHAR(128) !lk
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AS :4V8Iz 71
DECLARE @Name as NVARCHAR(128) ".Q``d&X
DECLARE @Owner as NVARCHAR(128)
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DECLARE @OwnerName as NVARCHAR(128) x]=s/+Y
DECLARE curObject CURSOR FOR 7ZsBYP8%
select 'Name' = name, p]-\\o}
'Owner' = user_name(uid) } qf=5v
from sysobjects f=L&>X
where user_name(uid)=@OldOwner Q*J8`J:#^R
order by name $k|:V&6SV
OPEN curObject :p@.aD5
FETCH NEXT FROM curObject INTO @Name, @Owner &Oih#I
WHILE(@@FETCH_STATUS=0) jrKRXS
BEGIN UbnX%2TW
if @Owner=@OldOwner :47bf<w|Y
begin ?2zbZ
set @OwnerName = @OldOwner + '.' + rtrim(@Name) v,VCbmc
exec sp_changeobjectowner @OwnerName, @NewOwner TJY
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end 2`?58&
-- select @name,@NewOwner,@OldOwner 3iI 4yg
FETCH NEXT FROM curObject INTO @Name, @Owner Q2L>P<87T
END EL?6x
close curObject h'tb
deallocate curObject &O:IRR7p
GO -szSA
10、SQL SERVER中直接循环写入数据 ,L.*95,
declare @i int P~H?[
;
set @i=1 lI<Q=gd
while @i<30 nbMxQODk
begin 3;hztCZj
insert into test (userid) values(@i) hN5?u:
set @i=@i+1 m 3Y@p$i5
end ~mR@L `"l
小记存储过程中经常用到的本周,本月,本年函数 t6+c"=P#
Dateadd(wk,datediff(wk,0,getdate()),-1) ]"2;x
Dateadd(wk,datediff(wk,0,getdate()),6) !pqfx93R*
Dateadd(mm,datediff(mm,0,getdate()),0) XDt MFig
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) )#H&lH
Dateadd(yy,datediff(yy,0,getdate()),0) I+VL~'VlS
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) BIk0n;Kz<L
上面的SQL代码只是一个时间段 xRI7_8Jpyn
Dateadd(wk,datediff(wk,0,getdate()),-1) 8?za&v
Dateadd(wk,datediff(wk,0,getdate()),6) RZgklEU
就是表示本周时间段. LrGLIt`
下面的SQL的条件部分,就是查询时间段在本周范围内的: sT*D]J
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Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 4Ucs9w3[
而在存储过程中 aJ{-m@/5
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) e}u68|\EC
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) OtVRhR3>