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。 *)H?d
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一、基础 9;sebqC?
1、说明:创建数据库 W=%}~7*
CREATE DATABASE database-name 68W&qzw.[r
2、说明:删除数据库 kk
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drop database dbname F@)wi0
3、说明:备份sql server ^4h/6^b0c
--- 创建 备份数据的 device <jY"+@rF
USE master bK<'J=#1
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' Mb"i}Yt{
--- 开始 备份 J*5 )g
BACKUP DATABASE pubs TO testBack `o)rAD^e
4、说明:创建新表 %F]4)XeW-+
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) K;k&w; j
根据已有的表创建新表: q0SYV
A:create table tab_new like tab_old (使用旧表创建新表) MXq+aS{
B:create table tab_new as select col1,col2... from tab_old definition only \l"1Io=
5、说明:删除新表 e4j:IK>
drop table tabname R>BnUIu
6、说明:增加一个列 -5\hZ!!J2
Alter table tabname add column col type )Gh"(]-<
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。 "+~La{POc
7、说明:添加主键: Alter table tabname add primary key(col) 'K"V{
说明:删除主键: Alter table tabname drop primary key(col) -1DQO|q#
8、说明:创建索引:create [unique] index idxname on tabname(col....) {OXKXRCa
删除索引:drop index idxname M]vcW
注:索引是不可更改的,想更改必须删除重新建。 .m9s+D]fI
9、说明:创建视图:create view viewname as select statement 3#!}W#xv
删除视图:drop view viewname Akb#1Ww4
10、说明:几个简单的基本的sql语句 #kR8v[Z
选择:select * from table1 where 范围 !c4pFQ B
插入:insert into table1(field1,field2) values(value1,value2) "6[fqW65
删除:delete from table1 where 范围 5k)/SAU0
更新:update table1 set field1=value1 where 范围 ~Uz,%zU#3
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! B>AmH%f/
排序:select * from table1 order by field1,field2 [desc] ^M0e 0
总数:select count as totalcount from table1 EuOrwmdj
求和:select sum(field1) as sumvalue from table1 xRuAt/aC
平均:select avg(field1) as avgvalue from table1 DZ<q)EpC
最大:select max(field1) as maxvalue from table1 & w&JE]$ 5
最小:select min(field1) as minvalue from table1 o $7:*jU
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11、说明:几个高级查询运算词 ( d#E16y
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A: UNION 运算符 U(4>e!
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 S%uwQ!=O8
B: EXCEPT 运算符 *9Ej fs7L
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 ]+@ @{?0
C: INTERSECT 运算符 Bvk 8b
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 s{#rCc)
注:使用运算词的几个查询结果行必须是一致的。 7O',X Y
12、说明:使用外连接 8eCC
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A、left outer join: UFr
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左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 qRlS^=#
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c >> yK_yg
B:right outer join: e%Rg,dX
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 OuWG.Za
C:full outer join: ]q~_
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 ?Imq4I~)
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二、提升 b*i_'k}*<g
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) f*)8bZDD
法一:select * into b from a where 1<>1 J$Uj@M
法二:select top 0 * into b from a mwU|Hh)N]
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) l.[S.@\ =.
insert into b(a, b, c) select d,e,f from b; %#kml{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) us%dw&
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 2l^hnog|
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. VJviX[V?4
4、说明:子查询(表名1:a 表名2:b) F6^Xi"R[
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) m?G@#[
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5、说明:显示文章、提交人和最后回复时间 #29m <f_n
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b _
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6、说明:外连接查询(表名1:a 表名2:b) 2NMS'"8
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c g-)izPX
7、说明:在线视图查询(表名1:a ) @#m@ .
select * from (SELECT a,b,c FROM a) T where t.a > 1; oMey^]!
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 vo<'7,
select * from table1 where time between time1 and time2 ;:nx6wi
select a,b,c, from table1 where a not between 数值1 and 数值2 T rK-XTev
9、说明:in 的使用方法 wyWe2d
select * from table1 where a [not] in ('值1','值2','值4','值6') /&1FgSARK
10、说明:两张关联表,删除主表中已经在副表中没有的信息 moz*=a
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) !(2rU @.
11、说明:四表联查问题: Ns
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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 ..... )zn`qaHK@e
12、说明:日程安排提前五分钟提醒 TC[(mf:8
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 "Bn8WT2?
13、说明:一条sql 语句搞定数据库分页 CNU,\>J@$
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 p8gm=
14、说明:前10条记录 g}\G@7Q
select top 10 * form table1 where 范围 xb8S)zO]Q
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.) ]c/k%]o~
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) A><w1-X&=o
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 re}_+svU
(select a from tableA ) except (select a from tableB) except (select a from tableC) AIN Fv;
17、说明:随机取出10条数据 \;#T.@c5
select top 10 * from tablename order by newid() iwM$U(
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18、说明:随机选择记录 J[ 0o6
select newid() .: dy d
19、说明:删除重复记录 R(.5Hs
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) P qUjBP\
20、说明:列出数据库里所有的表名 1V/?p<A
select name from sysobjects where type='U' Z@sDxYt9
21、说明:列出表里的所有的 <yNu/B.M
select name from syscolumns where id=object_id('TableName') =emcs%
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 ' 5tk0A
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type ^UJB%l
显示结果: ~F; ~
type vender pcs dbVMG-z8
电脑 A 1 bEvlk\iql
电脑 A 1 ) oypl+y
光盘 B 2 T- ~l2u|s
光盘 A 2 Pk{eGG<F$
手机 B 3 E]@$,)nC
手机 C 3 )O}q{4,}
23、说明:初始化表table1 ,76xa%k(U|
TRUNCATE TABLE table1 L'A9TW2
24、说明:选择从10到15的记录 - 2DvKW$
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc +wPXDN#R
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三、技巧 *h([ai"1-
1、1=1,1=2的使用,在SQL语句组合时用的较多 9Ub##5$[,
"where 1=1" 是表示选择全部 "where 1=2"全部不选, fGtYvl O-5
如: &AUtUp
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if @strWhere !='' M0) q
begin &d,!^9
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere h;C/} s
end Z.QgL=
else -/w#f&Y+]8
begin :o"9x,
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' uPhL?s{
end G>@KX
我们可以直接写成 !v fbgK
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere THN//}d
2、收缩数据库 [uLwr$N<%L
--重建索引 NP#6'eH\
DBCC REINDEX UgD|tuz]
DBCC INDEXDEFRAG 1U?,}w
--收缩数据和日志 `xXpP"*o}
DBCC SHRINKDB uCB>".'kM
DBCC SHRINKFILE 3bU(ea^e$
3、压缩数据库 Bz+zEXBC
dbcc shrinkdatabase(dbname) }w_r(g?\
4、转移数据库给新用户以已存在用户权限 U\'HB.P\
exec sp_change_users_login 'update_one','newname','oldname' <@448,9&
go _/c1b>kcso
5、检查备份集 ovXU +8
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' *r90IS}A$2
6、修复数据库 d94Le/E
ALTER DATABASE [dvbbs] SET SINGLE_USER tg~@(IT}j
GO nhdOo
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK /}kG$~
GO qdCcMcGt
ALTER DATABASE [dvbbs] SET MULTI_USER )hy(0 D
GO w,)O*1't
7、日志清除 VZ3{$0
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SET NOCOUNT ON * "qS
DECLARE @LogicalFileName sysname, 1-=ZIHW
@MaxMinutes INT, KkJrh@lk
@NewSize INT wJAJ /
USE tablename -- 要操作的数据库名 *DUP$@}k
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 iVSN>APe
@MaxMinutes = 10, -- Limit on time allowed to wrap log. UE\Z]t!
@NewSize = 1 -- 你想设定的日志文件的大小(M) RW4,j&)
-- Setup / initialize
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DECLARE @OriginalSize int G(;hJ'LT
SELECT @OriginalSize = size `uh+d
FROM sysfiles ,wYA_1$$H
WHERE name = @LogicalFileName BN>t"9XpW
SELECT 'Original Size of ' + db_name() + ' LOG is ' + qP k`e}D
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ASU.VY
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ou\M}C`E
FROM sysfiles b/soU2?^
WHERE name = @LogicalFileName \?_M_5Nb
CREATE TABLE DummyTrans o)2KQ$b>Q
(DummyColumn char (8000) not null) umo<9Y
DECLARE @Counter INT, eYQPK?jo
@StartTime DATETIME, 7cQFH@SC
@TruncLog VARCHAR(255) Cm"7f!(#
SELECT @StartTime = GETDATE(), Rp0`%}2
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@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' PP-U.
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 2{}8_G
EXEC (@TruncLog) <y2HzBC
-- Wrap the log if necessary. uvMcB9
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 7.y35y
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ZBuh(be
AND (@OriginalSize * 8 /1024) > @NewSize mMOjV_
BEGIN -- Outer loop. 2
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SELECT @Counter = 0 -]. a0
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) $<da<}b
BEGIN -- update q|zips,
INSERT DummyTrans VALUES ('Fill Log') YAP,#a
DELETE DummyTrans M*
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SELECT @Counter = @Counter + 1 Y/<`C
END l.Q.G<ol
EXEC (@TruncLog) Z{}+7P
END evvv&$&
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ;k:17&:8ue
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + y2M]z:Y U
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' K41Gn
FROM sysfiles aoHAB<.C
WHERE name = @LogicalFileName y!M# #K*
DROP TABLE DummyTrans [pxC3{|d$
SET NOCOUNT OFF NCa3")k
8、说明:更改某个表 Whl^~$+f
exec sp_changeobjectowner 'tablename','dbo' q}|_]R_y
9、存储更改全部表 mJ>msI
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CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch /T<))@$
@OldOwner as NVARCHAR(128), f\vMdY
@NewOwner as NVARCHAR(128) b*)F7{/Z
AS 8pXqgIbmb
DECLARE @Name as NVARCHAR(128) >&YUV.mLY
DECLARE @Owner as NVARCHAR(128) tjg?zlj
DECLARE @OwnerName as NVARCHAR(128) XGb*LY+Db6
DECLARE curObject CURSOR FOR x8!uI)#tS
select 'Name' = name, lj /IN[U/
'Owner' = user_name(uid) cd._q2
from sysobjects D k<NlH zp
where user_name(uid)=@OldOwner AL{iQxQ6
order by name R~"&E#C
OPEN curObject -, uT8'
FETCH NEXT FROM curObject INTO @Name, @Owner 1c|{<dFm
WHILE(@@FETCH_STATUS=0) {YK7';_E*
BEGIN A~X| vW
if @Owner=@OldOwner qM18Ji*
begin #b9V&/ln
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ;_S
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exec sp_changeobjectowner @OwnerName, @NewOwner yu}yON
end hem>@Bp'V
-- select @name,@NewOwner,@OldOwner n{I1ZlEeh
FETCH NEXT FROM curObject INTO @Name, @Owner 7{lWg x
END : "^/?Sd
close curObject 37b6w6{D
deallocate curObject 5t,X;
GO i`}!<{k
10、SQL SERVER中直接循环写入数据 2.
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declare @i int l4gZHMh'
set @i=1 6~OJB!
while @i<30 kgHZaQnD
begin YSbeCyv
insert into test (userid) values(@i) -Q6Vz=ku
set @i=@i+1
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end *?pnTQs^
小记存储过程中经常用到的本周,本月,本年函数 88KQ) NU
Dateadd(wk,datediff(wk,0,getdate()),-1) ^c]c`w
Dateadd(wk,datediff(wk,0,getdate()),6) 9qkJ<
Dateadd(mm,datediff(mm,0,getdate()),0) g(C/J9J
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) K5HzA1^
Dateadd(yy,datediff(yy,0,getdate()),0) SUDvKP
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) WP{U9YF2
上面的SQL代码只是一个时间段 9aBz%* xo
Dateadd(wk,datediff(wk,0,getdate()),-1) Qp9QSyMs}
Dateadd(wk,datediff(wk,0,getdate()),6) 8Z CR9%
就是表示本周时间段. 'Q"Mu
下面的SQL的条件部分,就是查询时间段在本周范围内的: eD|"?@cE
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) !u;gGgQF
而在存储过程中 3 MCV?"0
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) ${e5Ka
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 2cjbb kq