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。 DV\ei")
eeZysCy+DY
C#&6p0U
一、基础 0AKwZ'
&H
1、说明:创建数据库 !f-o,RJ
CREATE DATABASE database-name Zg&\K~OC
2、说明:删除数据库 i)i)3K2
drop database dbname \2xBOe-a]
3、说明:备份sql server L"I] mQvd
--- 创建 备份数据的 device P{!:pxu[
USE master 1qe^rz|
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 3{:<z4>{
--- 开始 备份 >}{-!
BACKUP DATABASE pubs TO testBack i q:Q$z&
4、说明:创建新表 Z3>xpw G
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) J*!:ar
根据已有的表创建新表: -0da"AB
A:create table tab_new like tab_old (使用旧表创建新表) oQ nk+> }%
B:create table tab_new as select col1,col2... from tab_old definition only A9Wqz"[
5、说明:删除新表 |u r~s$8y-
drop table tabname BQ&q<6Tk
6、说明:增加一个列 m`IQ+,e
Alter table tabname add column col type rDX'oP:
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。 m2CWQ[u
7、说明:添加主键: Alter table tabname add primary key(col) l\;mP.!
说明:删除主键: Alter table tabname drop primary key(col) SM+fG: 4d
8、说明:创建索引:create [unique] index idxname on tabname(col....) n qLAby_
删除索引:drop index idxname (TNY2Ke2 8
注:索引是不可更改的,想更改必须删除重新建。 u?;Vxh3@|
9、说明:创建视图:create view viewname as select statement `uZv9I"
删除视图:drop view viewname |;9 A{#zM
10、说明:几个简单的基本的sql语句 QlYs7zZ
选择:select * from table1 where 范围 C!{AnWf
插入:insert into table1(field1,field2) values(value1,value2) C%_
删除:delete from table1 where 范围 Vt=(2d5:p
更新:update table1 set field1=value1 where 范围 nH>V Da
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! $l,Zd6<1q
排序:select * from table1 order by field1,field2 [desc] `XSc >
总数:select count as totalcount from table1 Cz@FZb8
求和:select sum(field1) as sumvalue from table1 k5t^s
平均:select avg(field1) as avgvalue from table1 fj-pNl6Gf
最大:select max(field1) as maxvalue from table1 2K rqY
最小:select min(field1) as minvalue from table1 r7"A u"
Wx?&igh
(#B^Hyz!
g"]<J&
11、说明:几个高级查询运算词 noh|/sPMD
{ w8
!K
HKiVEg
A: UNION 运算符 =Esbeb7P
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。 w,![;wG
B: EXCEPT 运算符 Q5y
q"/=[a
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。 ~+<xFi
C: INTERSECT 运算符 &cu] vw
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。 a#Kmj0
注:使用运算词的几个查询结果行必须是一致的。 6c2ThtL
12、说明:使用外连接 mC:X4l]5
A、left outer join: w`j*W$82
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 4Hml.|$
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 ?UZ$bz
B:right outer join: EItxRHV5
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 7}d$*C
C:full outer join: niYz9YX
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。 nOoKGT
q8?=*1g
C!7U<rI
二、提升 K5!";V
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) emv ;m/&8
法一:select * into b from a where 1<>1 d<^_w!4X}
法二:select top 0 * into b from a V;iL[
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 'f-
insert into b(a, b, c) select d,e,f from b; wX)efLmyhY
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) H_?;h-Y]
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 W>Mse[6`c
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. WYwzo V-
4、说明:子查询(表名1:a 表名2:b) e86Aqehle
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) DC|xilP1O
5、说明:显示文章、提交人和最后回复时间 k40Ep(M}
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 0 NQ7#A
6、说明:外连接查询(表名1:a 表名2:b) =MTj4VXh"
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 0\5M^:8i3
7、说明:在线视图查询(表名1:a ) =<[7J]%
select * from (SELECT a,b,c FROM a) T where t.a > 1; bbd0ocva
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 cP*c(k~N
select * from table1 where time between time1 and time2
Z $!C=
select a,b,c, from table1 where a not between 数值1 and 数值2 AA))KBXq
9、说明:in 的使用方法 e>
ar
select * from table1 where a [not] in ('值1','值2','值4','值6') h`?y2?O
10、说明:两张关联表,删除主表中已经在副表中没有的信息 4@DVc7\x$
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) =QrA0kQR
11、说明:四表联查问题: )UR1E?'
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 ..... ZJ^s}
12、说明:日程安排提前五分钟提醒 >65
TkAp
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 gWFL
13、说明:一条sql 语句搞定数据库分页 HR[Q
?rg
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 d4d\0[
14、说明:前10条记录
LsQ s:O
select top 10 * form table1 where 范围 HS{P?~:=U
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.) ;US83%*
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 4$%`Qh>yA
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 nc<qbN
(select a from tableA ) except (select a from tableB) except (select a from tableC) xttYn]T
17、说明:随机取出10条数据 (tJ91SBl
select top 10 * from tablename order by newid() LL{t5(- _
18、说明:随机选择记录 /ca(a\@R
select newid() +d =~LQ}*
19、说明:删除重复记录 %h0D)6j
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) >/b^fAG
20、说明:列出数据库里所有的表名 (Ar?QwP9>
select name from sysobjects where type='U' ab{;Z5O
21、说明:列出表里的所有的 @|^jq
select name from syscolumns where id=object_id('TableName') gC0;2
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#Yx
TY
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 fzl=d_
显示结果: m6-76ma,hi
type vender pcs VR"8Di&)
电脑 A 1 9 >%+bA(
电脑 A 1 ?F1wh2oq
光盘 B 2 #`vVgGZ&
光盘 A 2 n-d:O\]
手机 B 3 _ ~|Q4AJ
手机 C 3 THJ
3-Ug
23、说明:初始化表table1 mIRAS"Q!m
TRUNCATE TABLE table1 B0v|{C
24、说明:选择从10到15的记录 6zuze0ud
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc +B# qu/By
2pz4rc
_y>}#6B
pOKeEW<q
三、技巧 "i&fp:E0
1、1=1,1=2的使用,在SQL语句组合时用的较多 Y hS{$Z
"where 1=1" 是表示选择全部 "where 1=2"全部不选, z<t>hzl7
如: ZlrhC= 0
if @strWhere !='' o'96ON0
begin GJvp{U}y9I
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere 8|6~o.B.G
end *(icR
else of=ql
begin zMr&1*CDX
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' ~U9q-/(J/
end >d97l&W
我们可以直接写成 :b5XKv^
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ^Wm*-4
2、收缩数据库 JxHv<p[
--重建索引 GoazH?%
DBCC REINDEX \TZ|S,FS
DBCC INDEXDEFRAG `4skwvS=
--收缩数据和日志 C;ptir1G;
DBCC SHRINKDB lQWBCJ8y
DBCC SHRINKFILE
^iuo^2+
3、压缩数据库 nn'Af,ko/
dbcc shrinkdatabase(dbname) u3ST;
4、转移数据库给新用户以已存在用户权限 **n y!
exec sp_change_users_login 'update_one','newname','oldname' @gEr+O1K(
go e+{BJN
vz
5、检查备份集 B2Z0
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' [EruyWK
6、修复数据库 tJAnuhX
ALTER DATABASE [dvbbs] SET SINGLE_USER SwX@I6huM
GO [Teh*CV
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK L0xsazX:x
GO AX K95eS
ALTER DATABASE [dvbbs] SET MULTI_USER 3
1k
GO >MPa38
7、日志清除 [83>T ,
SET NOCOUNT ON Wt:~S/l
DECLARE @LogicalFileName sysname, ##GY<\",;
@MaxMinutes INT, !vVT]k[N
@NewSize INT {"t5\U6cKM
USE tablename -- 要操作的数据库名 w,/6B&|
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 MO TE/JG
@MaxMinutes = 10, -- Limit on time allowed to wrap log. B$j' /e-Zk
@NewSize = 1 -- 你想设定的日志文件的大小(M) 8jNOEM(0Y+
-- Setup / initialize C5MqwNX
DECLARE @OriginalSize int ]w-.|vx
SELECT @OriginalSize = size _@K YF)
FROM sysfiles _JA:.V^3gm
WHERE name = @LogicalFileName >4c` UW
SELECT 'Original Size of ' + db_name() + ' LOG is ' + qlvwK&W<QM
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + &Sa~/!M
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' YXRjx.srf
FROM sysfiles 0MrN:M2B
WHERE name = @LogicalFileName XL~>rw<
CREATE TABLE DummyTrans &(7$&Q
(DummyColumn char (8000) not null) hkF^?AJ
DECLARE @Counter INT, _A3X6
@StartTime DATETIME, U!Mf]3
@TruncLog VARCHAR(255) OpUA{P
SELECT @StartTime = GETDATE(), wASX\D }
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' t}~UYG(h~
DBCC SHRINKFILE (@LogicalFileName, @NewSize) A_F0\ EN*
EXEC (@TruncLog) q :8\e
-- Wrap the log if necessary. #R<G,"N5
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 2vvh|?M
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) x`L+7,&n
AND (@OriginalSize * 8 /1024) > @NewSize bvp)r[8h
BEGIN -- Outer loop. D )gD<
SELECT @Counter = 0 (
OXY^iq
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) s`1^*Dl%+
BEGIN -- update 7 Kjj?~RA
INSERT DummyTrans VALUES ('Fill Log') CW;m
DELETE DummyTrans 1daL y
SELECT @Counter = @Counter + 1 QoseS/
END jzMg'z/@J
EXEC (@TruncLog) 0Az/fzJlz
END &g
{<HU?BT
SELECT 'Final Size of ' + db_name() + ' LOG is ' + H:{?3gk.P3
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + x{?sn
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' 0e\y~#-
FROM sysfiles `-u7 I
WHERE name = @LogicalFileName ~QCA -Yud
DROP TABLE DummyTrans k}s+ca!B
SET NOCOUNT OFF OEI3eizgH
8、说明:更改某个表 +(y>qd
exec sp_changeobjectowner 'tablename','dbo' FR["e1<0
9、存储更改全部表 MHFaSl
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch o$t
&MST?i
@OldOwner as NVARCHAR(128), 0O[l?e4,8{
@NewOwner as NVARCHAR(128) j-6v2MH
AS 5QOZ%9E&M
DECLARE @Name as NVARCHAR(128) OW#_ty_ul
DECLARE @Owner as NVARCHAR(128) ,ex]$fQ'
DECLARE @OwnerName as NVARCHAR(128) F+3!uWUK
DECLARE curObject CURSOR FOR w?S8@|MK
select 'Name' = name, s6/cL|Ex
'Owner' = user_name(uid) g&kH'fR8
from sysobjects -[Y:?lA
where user_name(uid)=@OldOwner 3;A$<s
order by name qh H+m
OPEN curObject <"A#Eok|4
FETCH NEXT FROM curObject INTO @Name, @Owner CC>($k"
WHILE(@@FETCH_STATUS=0) A6Q c;v+
BEGIN H) cQO?B
if @Owner=@OldOwner =EWD
|<
begin {zu/tCq?
set @OwnerName = @OldOwner + '.' + rtrim(@Name) %UBPoq
exec sp_changeobjectowner @OwnerName, @NewOwner }H; ]k-)
end ]| z")gOE
-- select @name,@NewOwner,@OldOwner \QiqcD9Y
FETCH NEXT FROM curObject INTO @Name, @Owner 3<3t;&e
END ^(J-dK
close curObject 7>
)l{7
deallocate curObject t"tNtLI
GO =/m}rcDN
10、SQL SERVER中直接循环写入数据 v|>BDN@,6
declare @i int [&Lxz~W][
set @i=1 =^by0E2
while @i<30 z30= ay1
begin 4 #G3ew
insert into test (userid) values(@i) aC4m{F[
set @i=@i+1 .N&QW
`
end F\:{}782u
小记存储过程中经常用到的本周,本月,本年函数
Re{ej
Dateadd(wk,datediff(wk,0,getdate()),-1) WVj&0
Dateadd(wk,datediff(wk,0,getdate()),6) jD<9=B(g
Dateadd(mm,datediff(mm,0,getdate()),0) fq{I$syY
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) D8W(CE^}
Dateadd(yy,datediff(yy,0,getdate()),0) %N!h38N2
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) %sYk0~E
上面的SQL代码只是一个时间段 L{zamVQG
Dateadd(wk,datediff(wk,0,getdate()),-1) - f+CyhR"*
Dateadd(wk,datediff(wk,0,getdate()),6) H9/XW6W,"w
就是表示本周时间段. Gl=@>Dc%
下面的SQL的条件部分,就是查询时间段在本周范围内的: !P+~c0DF
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) #xDDh`
而在存储过程中
sY&rbJ(P
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) S`iM.;|`O
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 54bF)<+