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。 7t,t`
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一、基础 _gKe%J&
1、说明:创建数据库 Vh}SCUof'
CREATE DATABASE database-name x0d~i!d
2、说明:删除数据库 9qS"uj
drop database dbname uKgZ$-'
3、说明:备份sql server XZw6Xtn
--- 创建 备份数据的 device JdZ+Hp3.
USE master P0`Mdk371
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 0]HYP;E"U
--- 开始 备份 L
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BACKUP DATABASE pubs TO testBack P/&]?f0/
4、说明:创建新表 ''\;z<v
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) q80S[au
根据已有的表创建新表: ]*7Y~dO
A:create table tab_new like tab_old (使用旧表创建新表) EUsI%p
B:create table tab_new as select col1,col2... from tab_old definition only vkLC-Mzm<
5、说明:删除新表 ;[RZ0Uy=
drop table tabname nx0K$Ptq
6、说明:增加一个列 +cU>k}
Alter table tabname add column col type qRbf2;
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。 h*u`X>!!
7、说明:添加主键: Alter table tabname add primary key(col) iAa;6mH
说明:删除主键: Alter table tabname drop primary key(col) "`6n6r42
8、说明:创建索引:create [unique] index idxname on tabname(col....) (H+'X}1
删除索引:drop index idxname Zo>]rKeV
注:索引是不可更改的,想更改必须删除重新建。 A.UUW
9、说明:创建视图:create view viewname as select statement {BHI1Uw
删除视图:drop view viewname bI|2@HV2
10、说明:几个简单的基本的sql语句 1~$);US
选择:select * from table1 where 范围 G%d
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插入:insert into table1(field1,field2) values(value1,value2) ioPUUUb)
删除:delete from table1 where 范围 yoAfc
更新:update table1 set field1=value1 where 范围 |p$spQ
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ePIiF_X
排序:select * from table1 order by field1,field2 [desc] _=|vgc
总数:select count as totalcount from table1 l7De6A"
求和:select sum(field1) as sumvalue from table1 6"dD2WV/
平均:select avg(field1) as avgvalue from table1 klUQkz |<a
最大:select max(field1) as maxvalue from table1 eW|^tH
最小:select min(field1) as minvalue from table1 O{ /q-~_
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11、说明:几个高级查询运算词 OT&k.!=
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A: UNION 运算符 y!]CJigpZ
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。 ExRe:^yU\
B: EXCEPT 运算符 7 I>G{
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。 epgPT'^
C: INTERSECT 运算符 sUPz/Z.h
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。 )&
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注:使用运算词的几个查询结果行必须是一致的。 -(K9s!C!.
12、说明:使用外连接 =/\:>+p^.y
A、left outer join: QNDHOo>v
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。 9(":,M(/o
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 {&Q9"C
B:right outer join: U4G`ZKv(!
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。 qY[xpm
C:full outer join: LY-2sa#B$-
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 ? R>h `
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二、提升 zRPeNdX
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) vB+ '
法一:select * into b from a where 1<>1 Zdn~`Q{
法二:select top 0 * into b from a Ao/ jt<
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) |g*XK6
insert into b(a, b, c) select d,e,f from b; ;qBu4'C)T
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) T9s2bC.z55
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 awz;z?~
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. .H,xle
4、说明:子查询(表名1:a 表名2:b) 8zMu7,E
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) V\6]n2
5、说明:显示文章、提交人和最后回复时间 t]Xw{)T
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 2<}NB?f`N
6、说明:外连接查询(表名1:a 表名2:b) YM
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select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c rSrIEP,c'
7、说明:在线视图查询(表名1:a ) j!3 Gz
select * from (SELECT a,b,c FROM a) T where t.a > 1; Uo2GK3nT
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 ;`6^6p\p
select * from table1 where time between time1 and time2 |2KAo!PI
select a,b,c, from table1 where a not between 数值1 and 数值2 cp o-.
9、说明:in 的使用方法 U)3DQ6T99
select * from table1 where a [not] in ('值1','值2','值4','值6') fNrgdfo
10、说明:两张关联表,删除主表中已经在副表中没有的信息 R i^[i}
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) tr7<]Hm:
11、说明:四表联查问题: i E CrI3s
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... /q5:p`4{J
12、说明:日程安排提前五分钟提醒 S%`0'lzzj
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 gynh#&r
13、说明:一条sql 语句搞定数据库分页 uIZWO.OdU
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 "U7qo}`I
14、说明:前10条记录 rylzcN9RM$
select top 10 * form table1 where 范围 M}!2H*
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.) PiA0]>
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) HF(KN{0.B
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 3d|9t9v
(select a from tableA ) except (select a from tableB) except (select a from tableC) YQY%M>F@d%
17、说明:随机取出10条数据 :^(>YAyHj^
select top 10 * from tablename order by newid() Qf@
18、说明:随机选择记录 '}$Dgp6e
select newid() N$[{8yil^w
19、说明:删除重复记录 8(* [Fe9
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) +!|9hF'
20、说明:列出数据库里所有的表名 NQ6sGL
select name from sysobjects where type='U' |DsnNk0c
21、说明:列出表里的所有的 xt*u4%
select name from syscolumns where id=object_id('TableName') ~*wk6&|
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。 tToTxf~
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 7nuU^wc
显示结果: AnT3M.>ek
type vender pcs p|]\P%,\
电脑 A 1 L`24?Y{
电脑 A 1 J_;o|gqX
光盘 B 2 w4gg@aO
光盘 A 2 |iwP:C^\mJ
手机 B 3 _]:z \TDn
手机 C 3 LGtIm7
23、说明:初始化表table1 V5rST +
TRUNCATE TABLE table1 KY~-;0x
24、说明:选择从10到15的记录 o>VVsH
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc G["c\Xux
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三、技巧 ' MxrQ;|S
1、1=1,1=2的使用,在SQL语句组合时用的较多 vuYSVI2=H
"where 1=1" 是表示选择全部 "where 1=2"全部不选, O6OP =K!t:
如: F|!){=
if @strWhere !='' VX1-JxY
begin \P6$mh\T
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere L+i(TM=
end /~<@ *-'
else |)*fRL,
begin q*9!,!e
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' aca=yDs2
end o !U
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我们可以直接写成 }B1!gz$YNO
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere ,l)^Ft`5
2、收缩数据库 Ct>GYk$
--重建索引 UNBH
DBCC REINDEX mrjswF27$o
DBCC INDEXDEFRAG g?ULWeZg5
--收缩数据和日志 _D+J!f^
DBCC SHRINKDB X93!bB
DBCC SHRINKFILE r!
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3、压缩数据库 ZEx}$<)_
dbcc shrinkdatabase(dbname) Ll4g[8
4、转移数据库给新用户以已存在用户权限 5bgs*.s
exec sp_change_users_login 'update_one','newname','oldname' - RU=z!{
go )<tI!I][j
5、检查备份集 S@/IQR
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' a5TioQ
6、修复数据库 i ,/0/?)*_
ALTER DATABASE [dvbbs] SET SINGLE_USER NN?`"Fww
GO gp\<p-}
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK J
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GO Kh_Lp$'0uM
ALTER DATABASE [dvbbs] SET MULTI_USER 2_Z ? #Y
GO 3(,?S$>
7、日志清除 rQ qW_t%
SET NOCOUNT ON w {3<{
DECLARE @LogicalFileName sysname, =aTv! 8</
@MaxMinutes INT, 1waTTT?"Ho
@NewSize INT L}pt)w*V1j
USE tablename -- 要操作的数据库名 W@I|Q -
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 Zo~
@MaxMinutes = 10, -- Limit on time allowed to wrap log. @P?~KW6<|
@NewSize = 1 -- 你想设定的日志文件的大小(M) io8'g3<
-- Setup / initialize ] &Rx@&e*
DECLARE @OriginalSize int u@cYw:-C
SELECT @OriginalSize = size =D<PVGo9
FROM sysfiles Rw0qcM\>|
WHERE name = @LogicalFileName |3KLk ?2
SELECT 'Original Size of ' + db_name() + ' LOG is ' + ^0\
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + ?m\t|/0Q
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' aq@8"b(.
FROM sysfiles LF& z
WHERE name = @LogicalFileName /$p6'1P8
CREATE TABLE DummyTrans Yz+ZY
(DummyColumn char (8000) not null) rr02pM0
DECLARE @Counter INT, M,\:<kNI
@StartTime DATETIME,
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@TruncLog VARCHAR(255) S;286[oq@
SELECT @StartTime = GETDATE(), Rx=>6,)'
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ]z/8KL
DBCC SHRINKFILE (@LogicalFileName, @NewSize) oV|4V:G q
EXEC (@TruncLog) \6 Zr
-- Wrap the log if necessary. [rV>57`YD
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 4p,EBn9(
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) '|8} z4/g
AND (@OriginalSize * 8 /1024) > @NewSize GE%Z9#E
BEGIN -- Outer loop. P 'od`
SELECT @Counter = 0 hFy;ffs.
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) DrY:9[LP
BEGIN -- update ]Hefm?9*^
INSERT DummyTrans VALUES ('Fill Log') j~jV'f.:H
DELETE DummyTrans =*c7i]@}
SELECT @Counter = @Counter + 1 .7avpOfz
END A#J`;5!Sc
EXEC (@TruncLog) lHPd"3HDK
END f\sQO&
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ]\hSI){
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + NRIG 1v>
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' UMm!B `M
FROM sysfiles biU^[g("
WHERE name = @LogicalFileName -7@/[9Gf`:
DROP TABLE DummyTrans zGkS^Z=(
SET NOCOUNT OFF |8l<$J
8、说明:更改某个表 @v)p<r^M">
exec sp_changeobjectowner 'tablename','dbo' :2rZcoNb.
9、存储更改全部表 8"8t-E#?
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch oldA#sA$
@OldOwner as NVARCHAR(128), Ki$MpA3j
@NewOwner as NVARCHAR(128) &-Gqdnc
AS Pama#6?OPh
DECLARE @Name as NVARCHAR(128) fY51:0{
DECLARE @Owner as NVARCHAR(128) f=r<nb'H
DECLARE @OwnerName as NVARCHAR(128) -~v2BN/
DECLARE curObject CURSOR FOR R\G0'?h
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select 'Name' = name, bU2Z[sn.
'Owner' = user_name(uid) ][+#;avU
from sysobjects 5A3xVN=
where user_name(uid)=@OldOwner 26I_YL,S
order by name W_\5nF
OPEN curObject c|B.n]Z
FETCH NEXT FROM curObject INTO @Name, @Owner !h23cj+V
WHILE(@@FETCH_STATUS=0) IYS)7`{]
BEGIN SwTL|+u
if @Owner=@OldOwner }J:U=HJ
begin :~tAUy":_*
set @OwnerName = @OldOwner + '.' + rtrim(@Name) #FCnA
exec sp_changeobjectowner @OwnerName, @NewOwner $0>60<J
end %7IugHH9y
-- select @name,@NewOwner,@OldOwner p93r'&Q
FETCH NEXT FROM curObject INTO @Name, @Owner t\k$};qJ
END @ hiCI.?X
close curObject /'l{E
deallocate curObject `(ue63AZ
GO ~obqG!2m
10、SQL SERVER中直接循环写入数据 "$+Jnc!!
declare @i int lm-dW'7&
set @i=1 P3x= 8_#
while @i<30 '
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begin Q
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insert into test (userid) values(@i)
-pf}
set @i=@i+1 59Xi3KY
end s
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小记存储过程中经常用到的本周,本月,本年函数 N `5,\TR2f
Dateadd(wk,datediff(wk,0,getdate()),-1) )NXmn95
Dateadd(wk,datediff(wk,0,getdate()),6) K/j3a[.
Dateadd(mm,datediff(mm,0,getdate()),0) A@1W}8qY:
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) bLij7K2H
Dateadd(yy,datediff(yy,0,getdate()),0) ~J wb`g.
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) RKHyw08
上面的SQL代码只是一个时间段 (2J: #
Dateadd(wk,datediff(wk,0,getdate()),-1) eg\v0Y!rI
Dateadd(wk,datediff(wk,0,getdate()),6) cl[BF'.H
就是表示本周时间段. 5\5/
下面的SQL的条件部分,就是查询时间段在本周范围内的: Y)0*b5?1r
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) DS.RURzd{r
而在存储过程中 A}G7l?V&
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) LrM=*Rh,O
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) DCIxRPw