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。 y9;Yivr)
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一、基础 fox6)Uot
1、说明:创建数据库 yX5\gO6G
CREATE DATABASE database-name FlQGgVN
2、说明:删除数据库 @c#(.=
drop database dbname >usL*b0%
3、说明:备份sql server =v\.h=~~
--- 创建 备份数据的 device ':q p05t
USE master *R"/ |Ka
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' O<I-
--- 开始 备份 i1085ztN
BACKUP DATABASE pubs TO testBack H::bwn`Vc
4、说明:创建新表 CAlCDfKW}
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) @d_M@\r=j
根据已有的表创建新表: KXrjqqXs
A:create table tab_new like tab_old (使用旧表创建新表) Z,=1buSz_
B:create table tab_new as select col1,col2... from tab_old definition only k!^{eOM
5、说明:删除新表 K@2),(z
drop table tabname Fcx&hj1gQ
6、说明:增加一个列 }qUX=s
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Alter table tabname add column col type $j~RWfw-
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。 3'Rx=G'
7、说明:添加主键: Alter table tabname add primary key(col) I'Hf{Erw
说明:删除主键: Alter table tabname drop primary key(col) gr{ DWCK
8、说明:创建索引:create [unique] index idxname on tabname(col....) ni<(K
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删除索引:drop index idxname %xW"!WbJ|
注:索引是不可更改的,想更改必须删除重新建。 Zfw,7am/
9、说明:创建视图:create view viewname as select statement 6b,V;#Anj
删除视图:drop view viewname [;N'=]`
10、说明:几个简单的基本的sql语句 NlqImM=r,
选择:select * from table1 where 范围 >~f]_puT
插入:insert into table1(field1,field2) values(value1,value2) l}h!B_P'
删除:delete from table1 where 范围 N mG#
更新:update table1 set field1=value1 where 范围 QPx^_jA
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! m'U0'}Ld};
排序:select * from table1 order by field1,field2 [desc] N+|d3X!
总数:select count as totalcount from table1 m~|40)
求和:select sum(field1) as sumvalue from table1 0J|3kY-n>
平均:select avg(field1) as avgvalue from table1 cK@wsA^4
最大:select max(field1) as maxvalue from table1 <v2;p}A
最小:select min(field1) as minvalue from table1 +_!QSU,@
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11、说明:几个高级查询运算词 RCrCs
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A: UNION 运算符 #4:?gfIj
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。 o-\[,}T)M
B: EXCEPT 运算符 `^vE9nW7
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。 sKWfXCd
C: INTERSECT 运算符 z}<^jgJ
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。 _`V'r#Qn
注:使用运算词的几个查询结果行必须是一致的。 VTM/hJmwJ
12、说明:使用外连接 wzA$'+Mb
A、left outer join: =|=(l)8
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 }bDm@NU
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c bcyzhK=
B:right outer join: 1 zZlC#V
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 ]5O~+Nf
C:full outer join: =]t|];c%
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 0b>h$OU/
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二、提升 _!6jR5&r,
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 6863xOv{T
法一:select * into b from a where 1<>1 1oS/`)
法二:select top 0 * into b from a #WuBL_nZ~
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) M}a6Vu9
insert into b(a, b, c) select d,e,f from b; 3]>| 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) 0sqFF[i
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 >z03{=sAN
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. ]]mJ']l
4、说明:子查询(表名1:a 表名2:b) qM`}{
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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) x:;kSh
5、说明:显示文章、提交人和最后回复时间 Q8NX)R
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b QZs!{sZ
6、说明:外连接查询(表名1:a 表名2:b) 4Ig;3 ^%71
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Y73C5.dNcE
7、说明:在线视图查询(表名1:a ) :h$$J
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select * from (SELECT a,b,c FROM a) T where t.a > 1; _w{Qtj~s|
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 !VJoM,b8
select * from table1 where time between time1 and time2 pRqx`5 }
select a,b,c, from table1 where a not between 数值1 and 数值2 ixFi{_
9、说明:in 的使用方法 .8R@2c`}Cs
select * from table1 where a [not] in ('值1','值2','值4','值6') m*pJBZxd
10、说明:两张关联表,删除主表中已经在副表中没有的信息 w(/S?d
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 6<]lW
11、说明:四表联查问题:
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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 ..... YVU7wW,1
12、说明:日程安排提前五分钟提醒 \G[$:nS
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 S!UaH>Rh
13、说明:一条sql 语句搞定数据库分页 3<!7>]A
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 M7T5
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14、说明:前10条记录 %4H%?4
select top 10 * form table1 where 范围 'V {W-W<
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) QY/w
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) UpG~[u)%@
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 \bcLiKE{
(select a from tableA ) except (select a from tableB) except (select a from tableC) fl(wV.Je|
17、说明:随机取出10条数据 NJ<F>3
select top 10 * from tablename order by newid() Q?vlfZR`8
18、说明:随机选择记录 (e~N q
select newid() X,
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19、说明:删除重复记录 6'/ #+,d'
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) D^O@'zP=At
20、说明:列出数据库里所有的表名 y0#2m6u
select name from sysobjects where type='U' [6fQ7uFMM8
21、说明:列出表里的所有的 gJXaPJA{
select name from syscolumns where id=object_id('TableName') +rd+0 `}C
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 V&5wRz+`W
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type 8=l%5r^cq
显示结果: q1,~
type vender pcs <YY 14p
电脑 A 1 #a6iuO0I
电脑 A 1 SU0
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光盘 B 2 ! mHO$bQ"
光盘 A 2 fVlB=8DNk&
手机 B 3 5+'<R8{:,
手机 C 3 X8|,
23、说明:初始化表table1 C _Dn{
TRUNCATE TABLE table1 :>
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24、说明:选择从10到15的记录 ;I}fBZ3
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc $i&zex{\
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三、技巧 )e{aN+
1、1=1,1=2的使用,在SQL语句组合时用的较多 d6O[ @CyP
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 5O%{{J
如: (>Em^(&
if @strWhere !='' I,tud!p`
begin {FkF
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere Psf#c:*_)
end kmW4:EA%
else Y4-t7UlS;
begin J5qZFD
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' -f .,tM=
end c)J%`i$
我们可以直接写成 ;uJMG
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 7! Nsm
2、收缩数据库 It(_v
--重建索引 &yg|t5o
DBCC REINDEX V!Uc(
DBCC INDEXDEFRAG 6m93puY`7
--收缩数据和日志 K1KreYlF
DBCC SHRINKDB N7"W{"3D
DBCC SHRINKFILE L0,'mS
3、压缩数据库 2G7Wi!J
dbcc shrinkdatabase(dbname) 3`g^
4、转移数据库给新用户以已存在用户权限 b}`TLn
exec sp_change_users_login 'update_one','newname','oldname' [JiH\+XLPs
go f|5co>Hk
5、检查备份集 7.Op<
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ?9/G[[(
6、修复数据库 sRs>"zAg
ALTER DATABASE [dvbbs] SET SINGLE_USER .*oU]N%K=
GO i5Ggf"![
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK e
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GO **%37
ALTER DATABASE [dvbbs] SET MULTI_USER =cI(d ,
GO P
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7、日志清除 fhiM U8(&
SET NOCOUNT ON V
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DECLARE @LogicalFileName sysname, {)XTk&"
@MaxMinutes INT, 79gT+~z
@NewSize INT N8jIMb'<
USE tablename -- 要操作的数据库名 <~)P7~$d?p
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 k[xSbs'D
@MaxMinutes = 10, -- Limit on time allowed to wrap log. HPl<%%TI
@NewSize = 1 -- 你想设定的日志文件的大小(M) ^qs $v06
-- Setup / initialize t Q)qCk07
DECLARE @OriginalSize int _6Sp QW
SELECT @OriginalSize = size B\~}3!j
FROM sysfiles oJ^P(] dw
WHERE name = @LogicalFileName X?O[r3<
SELECT 'Original Size of ' + db_name() + ' LOG is ' + K;?+8(H
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + V[LglPt
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' VA%J\T|G2\
FROM sysfiles I7onX,U+
WHERE name = @LogicalFileName ="+#W6bZT
CREATE TABLE DummyTrans z/-=%g >HA
(DummyColumn char (8000) not null) d]9z@Pd
DECLARE @Counter INT, 2/?|&[
@StartTime DATETIME, ch]IzdD
@TruncLog VARCHAR(255) #a#F,ZT
SELECT @StartTime = GETDATE(), KlEpzJ98
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 7CysfBF0g
DBCC SHRINKFILE (@LogicalFileName, @NewSize) :WEDAFq0
EXEC (@TruncLog) sJZiI}Xc
-- Wrap the log if necessary. >4TO=i
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired i-1op> Y
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) `5*}p#G
AND (@OriginalSize * 8 /1024) > @NewSize sHj/;
BEGIN -- Outer loop. 3o*YzwRt
SELECT @Counter = 0 -).C
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) )0`C@um
BEGIN -- update 81F9uM0
INSERT DummyTrans VALUES ('Fill Log') vM={V$D&
DELETE DummyTrans e\rp)[>'
SELECT @Counter = @Counter + 1 $xsd~L&
END pglVR </
EXEC (@TruncLog) E.h*g8bXe
END :gv"M8AP
SELECT 'Final Size of ' + db_name() + ' LOG is ' + F59 TZI
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + $4\j]RE!
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' *. t^MP
FROM sysfiles NEs:},)o
WHERE name = @LogicalFileName xT8?&Bx
DROP TABLE DummyTrans WJi]t9 3
SET NOCOUNT OFF +A+)=/i;
8、说明:更改某个表 UKGPtKE<
exec sp_changeobjectowner 'tablename','dbo' K/$KI7P
9、存储更改全部表 q.vIc
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CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Cp N>p.kM
@OldOwner as NVARCHAR(128), Wwo0%<2y
@NewOwner as NVARCHAR(128) e-;}366}
AS G@0&8
DECLARE @Name as NVARCHAR(128) V`5O{Gg
DECLARE @Owner as NVARCHAR(128) +@UV?"d
DECLARE @OwnerName as NVARCHAR(128) t20K!}D_
DECLARE curObject CURSOR FOR TeQV?ZQ#}
select 'Name' = name, xdPx{"C
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'Owner' = user_name(uid) DU^loB+
from sysobjects BtZ yn7a
where user_name(uid)=@OldOwner l (o~-i\M
order by name _1^'(5f$
OPEN curObject y_,bu^+*
FETCH NEXT FROM curObject INTO @Name, @Owner YSMAd-Ef-
WHILE(@@FETCH_STATUS=0) [[ZJ]^n,
BEGIN )7@0[>
if @Owner=@OldOwner )oZ dj`
begin lZ0 =;I
set @OwnerName = @OldOwner + '.' + rtrim(@Name) *p d@.|^)m
exec sp_changeobjectowner @OwnerName, @NewOwner 9WHddDA
end gw(z1L5
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-- select @name,@NewOwner,@OldOwner K3C <{#r
FETCH NEXT FROM curObject INTO @Name, @Owner kfNWI#'9
END f1? >h\F8
close curObject WIOV2+
deallocate curObject ICCc./l|
GO M5B# TAybC
10、SQL SERVER中直接循环写入数据 MD]>g>
declare @i int [QTV9
set @i=1 ~[: 2I
while @i<30 k)u[0}
begin =Qq+4F)MD
insert into test (userid) values(@i) Xj*Wu_
set @i=@i+1 hZ3bVi)L\
end 5;?yCWc
小记存储过程中经常用到的本周,本月,本年函数 1M-pr 8:6s
Dateadd(wk,datediff(wk,0,getdate()),-1) ,Q B<7a+I
Dateadd(wk,datediff(wk,0,getdate()),6) G3]4A&h9v~
Dateadd(mm,datediff(mm,0,getdate()),0) E7hhew
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) zDp 2g)
Dateadd(yy,datediff(yy,0,getdate()),0) POW>~Tof1
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) QJNFA}*>
上面的SQL代码只是一个时间段 0x7'^Z>-oe
Dateadd(wk,datediff(wk,0,getdate()),-1) $kgVa^
Dateadd(wk,datediff(wk,0,getdate()),6) NA*#~
就是表示本周时间段. l6B@qYLZ
下面的SQL的条件部分,就是查询时间段在本周范围内的: 3$w65=
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ^aQ"E9
而在存储过程中 g}i61(
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) PH"%kCI:
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) $(
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