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。 (3J$>Na
-K9c@?
gL_Y,A~Q{
一、基础 l&iq5}[n&
1、说明:创建数据库 OxI/%yv-c
CREATE DATABASE database-name pn.wud}R
2、说明:删除数据库 @=}YTtq
drop database dbname X/iT)R]b
3、说明:备份sql server h$4Hw+Yxs]
--- 创建 备份数据的 device =jB08A
USE master MrZh09y
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' n a9sm
--- 开始 备份 Tb3J9q+ya
BACKUP DATABASE pubs TO testBack BZzrRC
4、说明:创建新表 Ut2y;2)a
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ?c[*:N(
根据已有的表创建新表: |<:vY
A:create table tab_new like tab_old (使用旧表创建新表) "@??Fw!
B:create table tab_new as select col1,col2... from tab_old definition only &f^, la
5、说明:删除新表 dZi"$ g
drop table tabname T:5fc2Ngv
6、说明:增加一个列 {
^cV lC_
Alter table tabname add column col type ek#O3Oz
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。 !%"8|)CAr
7、说明:添加主键: Alter table tabname add primary key(col) .Fdgb4>BXX
说明:删除主键: Alter table tabname drop primary key(col) sBr_a5QQ#
8、说明:创建索引:create [unique] index idxname on tabname(col....) b )B?
F
删除索引:drop index idxname u(fm@+$^
注:索引是不可更改的,想更改必须删除重新建。 |&RU/ a
9、说明:创建视图:create view viewname as select statement qWQ/'M
删除视图:drop view viewname 8C*c{(4
10、说明:几个简单的基本的sql语句 V5UF3'3;}
选择:select * from table1 where 范围 9I&xfvD,
插入:insert into table1(field1,field2) values(value1,value2) < 1uZa
删除:delete from table1 where 范围 ,P;Pm68V
更新:update table1 set field1=value1 where 范围 r>o63Q:
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! -[cTx[Z,
排序:select * from table1 order by field1,field2 [desc] IZpP[hov
总数:select count as totalcount from table1 XD.)Dl8
求和:select sum(field1) as sumvalue from table1 A"L&a
l$i
平均:select avg(field1) as avgvalue from table1 hDF@'G8F
最大:select max(field1) as maxvalue from table1 '<"s \,
最小:select min(field1) as minvalue from table1 9[<)WQe6M
be.*#[
>CHrg]9
y*qVc E
11、说明:几个高级查询运算词 4 o Fel.o
Gefne[
E|iQc8gr&
A: UNION 运算符 f4fvrL
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。 'Gj3:-xqL
B: EXCEPT 运算符 Sc;BCl{=|
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。 a<^ v(r
C: INTERSECT 运算符 [_k1jHr48N
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。 yD zc<p\`
注:使用运算词的几个查询结果行必须是一致的。 EV]1ml k$
12、说明:使用外连接 "&Y`+ 0S8
A、left outer join: ;r<^a6B
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。 Ayxkv)%:@)
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 dYJ(!V&
B:right outer join: EJMM9(DQ7
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。 |fK1/<sz#
C:full outer join: "\w 7q
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。 v[1aWv:
ssfr}fzH
(A9Fhun
二、提升 M:Pc,
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) TM%|'^)
法一:select * into b from a where 1<>1 >g1~CEMN#
法二:select top 0 * into b from a ; ZA~p
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 0"<H;7K#W
insert into b(a, b, c) select d,e,f from b; j#!IuH\]
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^^[Q2LDU}
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 oH97=>
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 3lrT3a3vV
4、说明:子查询(表名1:a 表名2:b) /:m->
T
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) (KjoSN(
K
5、说明:显示文章、提交人和最后回复时间 <? q?Mn
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b |jGf<Bf5
6、说明:外连接查询(表名1:a 表名2:b) -*1d!
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c j'Fpjt"&=
7、说明:在线视图查询(表名1:a ) &*M!lxDN
select * from (SELECT a,b,c FROM a) T where t.a > 1; {'7B6
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 (S>C#A=E\
select * from table1 where time between time1 and time2 ]E5o1eeg
select a,b,c, from table1 where a not between 数值1 and 数值2 o_izl\
9、说明:in 的使用方法 i1 }:8Unxf
select * from table1 where a [not] in ('值1','值2','值4','值6') KLST\Ln:
10、说明:两张关联表,删除主表中已经在副表中没有的信息 YL!P0o13r
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) cN/6SGHK
11、说明:四表联查问题: Wf+cDpK
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 ..... [_BP)e
12、说明:日程安排提前五分钟提醒 n1Yp1"2b[
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 qU \w=
13、说明:一条sql 语句搞定数据库分页
Vr3Zu{&2
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 k
=>oO9`
14、说明:前10条记录 ?g_3 [Fk
select top 10 * form table1 where 范围 {:/#Nc$5
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) \1k79 c
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) yuh *
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 E^B'4
(select a from tableA ) except (select a from tableB) except (select a from tableC) ?qb}?&1
17、说明:随机取出10条数据 g@d*\ P)
select top 10 * from tablename order by newid() Tf>bX_L?
18、说明:随机选择记录 AP3a;4Z#
select newid() yl'u'-Zb6
19、说明:删除重复记录 5?f ^Rz
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) "BM#4
20、说明:列出数据库里所有的表名 nGC/R&
select name from sysobjects where type='U' 7y.kQI?3
21、说明:列出表里的所有的 ]vAz
select name from syscolumns where id=object_id('TableName') * `JYC
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。
\__i
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type 1s\Wtw:
显示结果: \UA[
type vender pcs )j6~Wy@4
电脑 A 1 B.=FSow
电脑 A 1 Lw1Yvtn
光盘 B 2 ldf\;Qk
光盘 A 2 %O;:af"Ja8
手机 B 3 [z:!j$K
手机 C 3 vz&|J
23、说明:初始化表table1 #`^}PuQ
TRUNCATE TABLE table1 F~-(:7j
24、说明:选择从10到15的记录 "MeVE#O
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc "69s)~
[+Iz@0q
R*,MfV
poE0{HOU
三、技巧 7g^]:3f!
1、1=1,1=2的使用,在SQL语句组合时用的较多 /PVk{3
"where 1=1" 是表示选择全部 "where 1=2"全部不选, PI {bmZ
如: Xg6Jh``
if @strWhere !='' ROI7eU
begin /|}EL%a
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere cVv=*81\
end j^*dmX
else b!t0w{^w
begin hgG9m[?K
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' "nynl'Ryk
end sI=xl
我们可以直接写成 gT.sjd
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere |"}FXaO
2、收缩数据库 ~12EQacOT
--重建索引 <_L,t 1H{
DBCC REINDEX ]h`&&B qt
DBCC INDEXDEFRAG e+7"/icK
--收缩数据和日志 K-)]
1BG
DBCC SHRINKDB LH.]DVj
DBCC SHRINKFILE tAd%#:K
3、压缩数据库 P8:dU(nlW
dbcc shrinkdatabase(dbname) 5Pc;5
o0C
4、转移数据库给新用户以已存在用户权限 6yG^p]zZ
exec sp_change_users_login 'update_one','newname','oldname' ^LnTOdAE
go 5{WE~8$
5、检查备份集 ?>:g?.+
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ,<_A2t 2
6、修复数据库 5DU6rks%
ALTER DATABASE [dvbbs] SET SINGLE_USER y-b%T|p9
GO rBzuKQK}J
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK HVCe;eI
GO >h9IM$2
ALTER DATABASE [dvbbs] SET MULTI_USER 9<?M8_
GO KZY}%il!`
7、日志清除 F{e@W([
SET NOCOUNT ON e2Pcm_Ahv*
DECLARE @LogicalFileName sysname, a5"D @E
@MaxMinutes INT, 5V~oIL
@NewSize INT &m7]v,&
USE tablename -- 要操作的数据库名 G_8R K,H.
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 7aRi5
@MaxMinutes = 10, -- Limit on time allowed to wrap log. $)i")=Hy
@NewSize = 1 -- 你想设定的日志文件的大小(M) FX&~\kmV'j
-- Setup / initialize +) om^e@.
DECLARE @OriginalSize int pU}(@oy
SELECT @OriginalSize = size 2zA4vZkbcw
FROM sysfiles ?!:ha;n
WHERE name = @LogicalFileName (,\+tr8r8
SELECT 'Original Size of ' + db_name() + ' LOG is ' + r+i($jMs
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + NNR`!Pty
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' |A~jsz6pI
FROM sysfiles 1=c\Rr9]
WHERE name = @LogicalFileName i#/Jr=
CREATE TABLE DummyTrans uBKgcpvTs
(DummyColumn char (8000) not null) t9` .bx8
DECLARE @Counter INT, ZF8 yw(z
@StartTime DATETIME, %N6A+5H
@TruncLog VARCHAR(255) V7Lxfoa4
SELECT @StartTime = GETDATE(), \ZFGw&yN
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' (Z q/
DBCC SHRINKFILE (@LogicalFileName, @NewSize) @V sG'
EXEC (@TruncLog) IqHV)A
-- Wrap the log if necessary. #U4F0BdA
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired YUD`!C
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) X/!o\yyT
AND (@OriginalSize * 8 /1024) > @NewSize rQs)O<jl
BEGIN -- Outer loop. dr}`H,X"3
SELECT @Counter = 0 L.2^`mZs
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) KeB"D!={;
BEGIN -- update z+wA
rPxc
INSERT DummyTrans VALUES ('Fill Log') ItVWO:x&v
DELETE DummyTrans 'RR~7h
SELECT @Counter = @Counter + 1 (O?.)jEW(.
END sN*N&XG
EXEC (@TruncLog) 29"'K.r
END Ecefi
pG
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ~9]hV7y5C
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 3?9IJ5p
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' rig,mv
FROM sysfiles &< `N T D
WHERE name = @LogicalFileName *uf'zQ<9
DROP TABLE DummyTrans Ad8n<zt|
SET NOCOUNT OFF $E~`\o%Ev
8、说明:更改某个表 <n];mfh1
exec sp_changeobjectowner 'tablename','dbo' nZyX|SPk
9、存储更改全部表 7
:x fPx
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch n8
i] z
@OldOwner as NVARCHAR(128), ay
;S4c/_
@NewOwner as NVARCHAR(128) 1\~ "VF*{
AS ?k&Vy
DECLARE @Name as NVARCHAR(128) ,t?B+$E
DECLARE @Owner as NVARCHAR(128) ,X-bJA@(
DECLARE @OwnerName as NVARCHAR(128) C.yQ=\U2
DECLARE curObject CURSOR FOR $?Hu#Kn,(
select 'Name' = name, 4#xDgxg\f
'Owner' = user_name(uid) jyUjlYAAv`
from sysobjects 9igiZmM
where user_name(uid)=@OldOwner 4y?n
[/M/
order by name u(>^3PJ+
OPEN curObject p!7FpxZY
FETCH NEXT FROM curObject INTO @Name, @Owner XB^'K2
WHILE(@@FETCH_STATUS=0) Vpz\.]
BEGIN <I\/n<*
if @Owner=@OldOwner Uw. `7b>B
begin 8,4"uuI
set @OwnerName = @OldOwner + '.' + rtrim(@Name) { ]{/t-=
exec sp_changeobjectowner @OwnerName, @NewOwner /<=u\e'rE
end QL&ZjSN
-- select @name,@NewOwner,@OldOwner ]Ji.Zk
FETCH NEXT FROM curObject INTO @Name, @Owner v5#jZ$<F
END uM IIYS
close curObject feDlH[$
deallocate curObject t ;;U}
GO |O|V-f{l
10、SQL SERVER中直接循环写入数据 |!3DPA(_
declare @i int 4i azNl#
set @i=1 w!-gJmX>
while @i<30 ghG**3xr
begin {j?FNOJn
insert into test (userid) values(@i) *SDs;kg
set @i=@i+1 N1}sHyVq7
end u<tbbKM
小记存储过程中经常用到的本周,本月,本年函数 yy^q2P
Dateadd(wk,datediff(wk,0,getdate()),-1) '4+
ur`
Dateadd(wk,datediff(wk,0,getdate()),6) {9&;Q|D z
Dateadd(mm,datediff(mm,0,getdate()),0) +NZ_D#u
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) _LEK%
Dateadd(yy,datediff(yy,0,getdate()),0) 6$Xzpg(o
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) x:NY\._
上面的SQL代码只是一个时间段 0WW2i{7`U
Dateadd(wk,datediff(wk,0,getdate()),-1) z,[Hli*0
Dateadd(wk,datediff(wk,0,getdate()),6) ICx#{q@f,
就是表示本周时间段. QC
OM_$ y
下面的SQL的条件部分,就是查询时间段在本周范围内的: {tuYs:
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) #4Rx]zW^%
而在存储过程中 1QcNp(MO
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) dk#k bG;
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ]___M