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。 FW DuH`-5
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一、基础 ]eW|}V7A:
1、说明:创建数据库 ,NEs{!
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CREATE DATABASE database-name 3kCbD=yF
2、说明:删除数据库 Y14R"*t~
drop database dbname {1aAm+
3、说明:备份sql server #!jRY!2Vt
--- 创建 备份数据的 device s
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USE master Rda1X~-g
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' e<4z)
--- 开始 备份 ?+5{HFx
BACKUP DATABASE pubs TO testBack I_G>W3
4、说明:创建新表 iyYY)roB
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) h50StZ8Yr
根据已有的表创建新表: es[5B* 5
A:create table tab_new like tab_old (使用旧表创建新表) rfRo*u2"
B:create table tab_new as select col1,col2... from tab_old definition only e:LZ s0
5、说明:删除新表 rR@n>
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drop table tabname ,6O9#1A&i
6、说明:增加一个列
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Alter table tabname add column col type nnL$m_K~
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。 oks=|'&
7、说明:添加主键: Alter table tabname add primary key(col) Qz+d[%Q}x
说明:删除主键: Alter table tabname drop primary key(col) jF{gDK
8、说明:创建索引:create [unique] index idxname on tabname(col....) &&1Y"dFs
删除索引:drop index idxname $|(|Qzi%
注:索引是不可更改的,想更改必须删除重新建。 S7ehk*`
9、说明:创建视图:create view viewname as select statement S}^s5ztm
删除视图:drop view viewname I~LQ1_
10、说明:几个简单的基本的sql语句 F/*fQAa"
选择:select * from table1 where 范围 }Tr83B|
插入:insert into table1(field1,field2) values(value1,value2) z<6P3x|
删除:delete from table1 where 范围 }c4E 2c
更新:update table1 set field1=value1 where 范围 : .o=F`W
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! gAA
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排序:select * from table1 order by field1,field2 [desc] ;"Y;l=9_
总数:select count as totalcount from table1 hlFU"u_
求和:select sum(field1) as sumvalue from table1 qTHg[sME
平均:select avg(field1) as avgvalue from table1 l5';?>!s
最大:select max(field1) as maxvalue from table1 -ouJf}#R
最小:select min(field1) as minvalue from table1 kgI=0W>
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11、说明:几个高级查询运算词 C.eV|rc@T
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A: UNION 运算符 {0vbC/?]
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 EO/cW<uV'
B: EXCEPT 运算符 RO$@>vL
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。 (
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C: INTERSECT 运算符 1gShV ]2
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。 o\ow{gh9
注:使用运算词的几个查询结果行必须是一致的。 ,eeL5V
12、说明:使用外连接 +%}5{lu_e
A、left outer join: B N*,!fx
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。 3cfZ!E~^kc
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 CESe}^)n
B:right outer join: Wytvs*\`
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。 t7oz9fSz=?
C:full outer join: rfXF 01I
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。 "UoCT7X
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二、提升 t6bWSz0
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) I0l.KiBm
法一:select * into b from a where 1<>1 nhP~jJn
法二:select top 0 * into b from a I"Q9W|J_&
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) *T>#zR{
insert into b(a, b, c) select d,e,f from b; ;8L+_YCa
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) bOxjm`B<
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 W_BAb+$aF
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. (#-=y~%
4、说明:子查询(表名1:a 表名2:b) /[|}rqX(
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) GATP
5、说明:显示文章、提交人和最后回复时间 )|Vg/S
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b b*FU*)<4.
6、说明:外连接查询(表名1:a 表名2:b) SEQO2`]e:
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c bm tJU3Rm
7、说明:在线视图查询(表名1:a ) ?mYV\kDt\
select * from (SELECT a,b,c FROM a) T where t.a > 1; j |'#5H`
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 @%G' U&R{
select * from table1 where time between time1 and time2 D2TXOPH
select a,b,c, from table1 where a not between 数值1 and 数值2 SJ@8[n.x
9、说明:in 的使用方法 yToT7 X7F7
select * from table1 where a [not] in ('值1','值2','值4','值6') e1`)3-f
10、说明:两张关联表,删除主表中已经在副表中没有的信息 ;ad9{":J#B
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 4('0f:9z+
11、说明:四表联查问题: GwMUIevO_
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... .}$`+h8WT
12、说明:日程安排提前五分钟提醒 Y1yXB).AH8
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 f^6&Fb>
13、说明:一条sql 语句搞定数据库分页 uD ?I>7
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 p9&gEW
14、说明:前10条记录 Nn,vdu{^2
select top 10 * form table1 where 范围 K{=r.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.) [I++>4
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 7dufY
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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 S&
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(select a from tableA ) except (select a from tableB) except (select a from tableC) SrQ4y`?
17、说明:随机取出10条数据 *%Nns',
select top 10 * from tablename order by newid() <nOuyGIZ
18、说明:随机选择记录 r?"}@MRW
select newid() 1&8j3"
19、说明:删除重复记录 GFQG(7G9
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ~51kiQW
20、说明:列出数据库里所有的表名 _cxm}*}\#
select name from sysobjects where type='U' %;=IMMK
21、说明:列出表里的所有的 Imh2~rw;
select name from syscolumns where id=object_id('TableName') PUQ_w
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。 =#.8$oa^
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type %)<oX9E
显示结果: OUlxeo/
type vender pcs I*+LJy;j
电脑 A 1 )I Y 5Y
电脑 A 1 XDP6T"h
光盘 B 2 r|\5'ZMx
光盘 A 2 2rR@2Vsw2
手机 B 3 ?b*/ddIs
手机 C 3 EaM"=g
23、说明:初始化表table1 'FPcAW^8
TRUNCATE TABLE table1 45r]wT(C
24、说明:选择从10到15的记录 vu_>U({.
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select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc =A0"0D{\
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三、技巧 `eMrP`
1、1=1,1=2的使用,在SQL语句组合时用的较多 1BMV=_
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 0^<Skm27"
如: ~!3t8Hx6
if @strWhere !='' [0% yJH
begin NSMjr_
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere R
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end :c~9>GCE&
else PSP1>-7)w
begin fB;&n
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 5(iSOsb
end IKMsY5i
我们可以直接写成 36kc4=
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere QoW(tM
2、收缩数据库 6o[0sM_];
--重建索引 vWqyZ-p,q
DBCC REINDEX vI
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DBCC INDEXDEFRAG 3t"~F%4-}
--收缩数据和日志
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DBCC SHRINKDB u|_LR5S!j
DBCC SHRINKFILE kz7vbY
3、压缩数据库 2cs?("8e%
dbcc shrinkdatabase(dbname) e/]O<, *
4、转移数据库给新用户以已存在用户权限 c{'$=lR "
exec sp_change_users_login 'update_one','newname','oldname' ys&"r":I
go g^s+C Z
5、检查备份集 wq:b j=j
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' M(;y~|e
6、修复数据库 ['51FulDR
ALTER DATABASE [dvbbs] SET SINGLE_USER $?]@_=
GO F9m 2C'U
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK Ur_S
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GO jsk:fh0~M
ALTER DATABASE [dvbbs] SET MULTI_USER p/ziFpU
GO Ek"YM[
7、日志清除 \S=XIf
SET NOCOUNT ON uD.
DECLARE @LogicalFileName sysname, >Jm-2W5J
@MaxMinutes INT, \&eY)^vw
@NewSize INT =gMaaGg p,
USE tablename -- 要操作的数据库名 ' +)6#/*
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 -{yDk$"
@MaxMinutes = 10, -- Limit on time allowed to wrap log. DHh+%|e
@NewSize = 1 -- 你想设定的日志文件的大小(M) SBCL1aM
-- Setup / initialize _/8_,9H
DECLARE @OriginalSize int |Q5H9<*
SELECT @OriginalSize = size k9*J*7l-m
FROM sysfiles ax-=n (
WHERE name = @LogicalFileName 4'+d"Ok
SELECT 'Original Size of ' + db_name() + ' LOG is ' + T4V[RN
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 96.IuwL*.s
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' SjZd0H0
FROM sysfiles 3gxf~$)?
WHERE name = @LogicalFileName U-Af7qO
CREATE TABLE DummyTrans #t"9TP
(DummyColumn char (8000) not null) vqrBRlZ
DECLARE @Counter INT, M*g2VyZ
@StartTime DATETIME, $x;tSJ)m~
@TruncLog VARCHAR(255) Nf=C?`L
SELECT @StartTime = GETDATE(), )x$!K[=
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' y-E1]4?})
DBCC SHRINKFILE (@LogicalFileName, @NewSize) z7'n, [
EXEC (@TruncLog) ]sX7%3P
-- Wrap the log if necessary. WafdE
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired Q;XXgX#l
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) j G+T.
AND (@OriginalSize * 8 /1024) > @NewSize R19'|TJ
BEGIN -- Outer loop. qJ\X~5{
SELECT @Counter = 0 #Y;.>mF
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) %3]3r*e&5
BEGIN -- update Sp<hai
INSERT DummyTrans VALUES ('Fill Log') !&@2
DELETE DummyTrans 1P5*wNF
SELECT @Counter = @Counter + 1 ~ GNyE*t/Y
END bcq@N
EXEC (@TruncLog) -(6eVI
END mcvDxjk,h
SELECT 'Final Size of ' + db_name() + ' LOG is ' + PfVEv *
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + re7!p(W?,
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' dj?G.-
FROM sysfiles V8-4>H}Cb/
WHERE name = @LogicalFileName lKf Mp1
DROP TABLE DummyTrans *}+R{
SET NOCOUNT OFF L=d$"Q
8、说明:更改某个表 qv.[k<~a>
exec sp_changeobjectowner 'tablename','dbo' \z2vV+f
9、存储更改全部表 y' 2<qj
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch cge-'/8w%
@OldOwner as NVARCHAR(128), vad|Rp l
@NewOwner as NVARCHAR(128) Zn?8\
AS 60~v
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DECLARE @Name as NVARCHAR(128) S|l&fb n
DECLARE @Owner as NVARCHAR(128) UP\8w#~
DECLARE @OwnerName as NVARCHAR(128) {;U} :Dx
DECLARE curObject CURSOR FOR w+Ad$4Pf"
select 'Name' = name, G"}qV%"6"
'Owner' = user_name(uid) )$MS
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from sysobjects [Dnusp7e
where user_name(uid)=@OldOwner (&q@~
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order by name w#W5}i&x
OPEN curObject AdDQWJ^r
FETCH NEXT FROM curObject INTO @Name, @Owner t$aVe"uM
WHILE(@@FETCH_STATUS=0) 6!*K/2:O
BEGIN H!p!sn
if @Owner=@OldOwner %(fL?
begin |d5ggf.w
set @OwnerName = @OldOwner + '.' + rtrim(@Name) Q%rVo4M#2
exec sp_changeobjectowner @OwnerName, @NewOwner #1MKEfv(~
end 55LgBD
-- select @name,@NewOwner,@OldOwner P~&O4['<
FETCH NEXT FROM curObject INTO @Name, @Owner TLy;4R2Nn
END IoQr+:_R
close curObject yU> T8oFh
deallocate curObject 'T%IvJ#Xu
GO AlUJ1^o)
10、SQL SERVER中直接循环写入数据 ri,2clp
declare @i int Xe)Pg)J1
set @i=1 o\d |CE;>
while @i<30 TV?
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begin n:F@gZd`
insert into test (userid) values(@i) $,!hD\a
set @i=@i+1 p#)e:/Qy
end ,Ie<'>hd
小记存储过程中经常用到的本周,本月,本年函数 tzZ|S<e6=\
Dateadd(wk,datediff(wk,0,getdate()),-1) 6!@0VI&P
Dateadd(wk,datediff(wk,0,getdate()),6) Bhj:9%`
Dateadd(mm,datediff(mm,0,getdate()),0) &.hoCPo$
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) JL@F~U9
Dateadd(yy,datediff(yy,0,getdate()),0) 6ezcS}:+
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) ~'(9?81d
上面的SQL代码只是一个时间段
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Dateadd(wk,datediff(wk,0,getdate()),-1) ?%93b ,7
Dateadd(wk,datediff(wk,0,getdate()),6) 9-B@GFB;8
就是表示本周时间段. D^N[=q99&e
下面的SQL的条件部分,就是查询时间段在本周范围内的: H%FM
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ^Wf
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而在存储过程中 g/x_m.
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) B.El a
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) FZeP<Ban