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。 l[q%1-N
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一、基础 &[hq !v
1、说明:创建数据库 1>SCY_Cv
CREATE DATABASE database-name ~"+Fp&[9f
2、说明:删除数据库 9\]%N;;Lo
drop database dbname -
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3、说明:备份sql server t<6`?\Gk
--- 创建 备份数据的 device {IW pI *
USE master nsJN)Pt
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' '_~=C-g
--- 开始 备份 Ex
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BACKUP DATABASE pubs TO testBack `_6!nkq8
4、说明:创建新表 P#g"c.?;
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) K~_[[)14b
根据已有的表创建新表: FasA f(3
A:create table tab_new like tab_old (使用旧表创建新表) {yy^DlHb
B:create table tab_new as select col1,col2... from tab_old definition only bS+by'Ea1W
5、说明:删除新表 Dm1;mR S+
drop table tabname y+XB
6、说明:增加一个列 .`OdnLGy
Alter table tabname add column col type I
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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。 0~\Dd0W/:`
7、说明:添加主键: Alter table tabname add primary key(col) 9@-^!DBM
说明:删除主键: Alter table tabname drop primary key(col) P!{
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8、说明:创建索引:create [unique] index idxname on tabname(col....) I T)rhi:
删除索引:drop index idxname -VESe}c:nQ
注:索引是不可更改的,想更改必须删除重新建。 mk;l;!*T8
9、说明:创建视图:create view viewname as select statement zhDmZ
删除视图:drop view viewname `V@{#+X
10、说明:几个简单的基本的sql语句 u $N2uFc
选择:select * from table1 where 范围 VR>;{>~
插入:insert into table1(field1,field2) values(value1,value2) $^Dx4:k<2
删除:delete from table1 where 范围 3+;}2x0-F
更新:update table1 set field1=value1 where 范围 pNo<:p
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! a(X?N.w
排序:select * from table1 order by field1,field2 [desc] p
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总数:select count as totalcount from table1 7B$iM,}.b
求和:select sum(field1) as sumvalue from table1
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平均:select avg(field1) as avgvalue from table1 (L?fYSP!
最大:select max(field1) as maxvalue from table1 yFT)R hN
最小:select min(field1) as minvalue from table1 "$?f&*
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11、说明:几个高级查询运算词 Y#_,Ig5.
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A: UNION 运算符 >ln% 3=
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 Kc*h@#`~oL
B: EXCEPT 运算符 v?)-KtX|
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 e`#c[lbAAM
C: INTERSECT 运算符 Y?2I
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INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 M`ETH8Su=
注:使用运算词的几个查询结果行必须是一致的。 4}{HRs?
12、说明:使用外连接 SLL%XF~/Sb
A、left outer join: q@ >s#
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 jd$uOn.r
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 [ds:LQq)/
B:right outer join: a[:0<Ek
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。 n^|n6(EZ
C:full outer join: /lSz8h2
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。 -y{o@
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二、提升 [0D( PV(n
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) pq6}q($Rk
法一:select * into b from a where 1<>1 [Z484dS`_
法二:select top 0 * into b from a s#ijpc>h
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ?k~(E`ZE3
insert into b(a, b, c) select d,e,f from b; ]&1Kz
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3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 3~\mP\/4v
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 \iAkF`OC
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. rLNo7i
4、说明:子查询(表名1:a 表名2:b) g*b`V{/Vw
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) ?yF)tF+<
5、说明:显示文章、提交人和最后回复时间 wAxXK94#3
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b D;It0"
6、说明:外连接查询(表名1:a 表名2:b) -cCujDM#T
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c Ql>DS~a
7、说明:在线视图查询(表名1:a ) mHo}, |
select * from (SELECT a,b,c FROM a) T where t.a > 1; ^ad
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8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 g]R }w@nJ
select * from table1 where time between time1 and time2 M-u:8dPu
select a,b,c, from table1 where a not between 数值1 and 数值2 <k'=_mC_
9、说明:in 的使用方法 +qe!KPk2
select * from table1 where a [not] in ('值1','值2','值4','值6') sTO*
10、说明:两张关联表,删除主表中已经在副表中没有的信息 E)m{m$Hb
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 'D8WNZ8Q
11、说明:四表联查问题: w1/pwzn
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 ..... U7.3`qd"
12、说明:日程安排提前五分钟提醒 ~]DGf(
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 V<AT"vU[
13、说明:一条sql 语句搞定数据库分页 3qPj+@
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 j0!Z 20
14、说明:前10条记录 m]BxGwT=m
select top 10 * form table1 where 范围 A^2VH$j]+
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) n'{cU(
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 5bX
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16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 c4oQ4
(select a from tableA ) except (select a from tableB) except (select a from tableC) jEsP: H(0^
17、说明:随机取出10条数据 S,m)yh.
select top 10 * from tablename order by newid() Mxn>WCPo
18、说明:随机选择记录 @.T
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select newid() (,`ypD +3q
19、说明:删除重复记录 4mJ4)
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ~`c?&YixU
20、说明:列出数据库里所有的表名 1q<BYc+z
select name from sysobjects where type='U' {wRs V=*
21、说明:列出表里的所有的 |ul25/B
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select name from syscolumns where id=object_id('TableName') Mo|[Muj8b
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 <\GP\G
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type zME75;{
显示结果: Od70w*,
type vender pcs sPn[FuT>+s
电脑 A 1 EA9`-xs|
电脑 A 1
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光盘 B 2 mL`,v
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光盘 A 2 9S@PY_ms
手机 B 3 [op!:K0
手机 C 3 eKNZ?!c=
23、说明:初始化表table1 :}0y[qc3
TRUNCATE TABLE table1 _Iy0-=G
24、说明:选择从10到15的记录 NARW3\
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc tvynl;Y/
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三、技巧 K O "U5v
1、1=1,1=2的使用,在SQL语句组合时用的较多 =4uL1[0'
"where 1=1" 是表示选择全部 "where 1=2"全部不选, Mib(J+Il
如: %mPIr4$Pg
if @strWhere !='' e5_a.c
begin U7O~ch[,
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere ?9nuL}m!a
end $5ZBNGr
else {^2``NYM_
begin eWSA
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' PXG)?`^NX
end S\K;h/;V
我们可以直接写成 NL
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere .5'M^
2、收缩数据库 yB\}e'J^
--重建索引 MW8GM }Ho[
DBCC REINDEX H=[eO
DBCC INDEXDEFRAG AJt*48H*G
--收缩数据和日志 :@{(^}N8u
DBCC SHRINKDB ED&>~~k)
DBCC SHRINKFILE t7tX<|aN
3、压缩数据库 Ql^I$5&
dbcc shrinkdatabase(dbname) FuiG=quY
4、转移数据库给新用户以已存在用户权限 Hj't.lg+j
exec sp_change_users_login 'update_one','newname','oldname' wUj[c7Y%
go M eo(|U
5、检查备份集 j'FSd*5m
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ;rYL\`6L
6、修复数据库 Nw[TP
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ALTER DATABASE [dvbbs] SET SINGLE_USER rk:^^r>5Qi
GO F|3Te?_
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK #qY`xH'>
GO hp+=UnW
ALTER DATABASE [dvbbs] SET MULTI_USER )isz
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GO awh<CmcZ
7、日志清除 9HrT>{@
SET NOCOUNT ON n@ lf+
DECLARE @LogicalFileName sysname, , f{<
@MaxMinutes INT, WzZ<ZCHm
@NewSize INT S[(Tpk2_
USE tablename -- 要操作的数据库名 |;e K5(|
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 Aon3G
@MaxMinutes = 10, -- Limit on time allowed to wrap log. P*Va<'{:{
@NewSize = 1 -- 你想设定的日志文件的大小(M) LgXc}3
-- Setup / initialize <VI.A" Qk~
DECLARE @OriginalSize int pA7&
SELECT @OriginalSize = size ZN#mu]jC?
FROM sysfiles cO%-Av~P
WHERE name = @LogicalFileName "/[xak!g
SELECT 'Original Size of ' + db_name() + ' LOG is ' + n4,b?-E>(
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + _0dm?=
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' / r6^]grg
FROM sysfiles #&<>|m
WHERE name = @LogicalFileName <y[LdB/a
CREATE TABLE DummyTrans 4\
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(DummyColumn char (8000) not null) -l)vl<}
DECLARE @Counter INT, [AkL6
@StartTime DATETIME, V
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@TruncLog VARCHAR(255) 4H'\nsM
SELECT @StartTime = GETDATE(), x9Um4!/t
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' l# u$w&
DBCC SHRINKFILE (@LogicalFileName, @NewSize) xa#;<8 iV
EXEC (@TruncLog) EYWRTh
-- Wrap the log if necessary. y,'M3GGl
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired `L# pN5
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) KBJ%$OQV
AND (@OriginalSize * 8 /1024) > @NewSize ScOiOz:Ha
BEGIN -- Outer loop. v,bCj6
SELECT @Counter = 0 K",YAfJa
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) &iR3]FNI
BEGIN -- update :}(Aq;}X
INSERT DummyTrans VALUES ('Fill Log') :_9MS0
DELETE DummyTrans &$$KC?!w
SELECT @Counter = @Counter + 1 (%.[MilxPM
END L~9Q7 6w
EXEC (@TruncLog) 5hN)y-4@
END [Z~h!}
SELECT 'Final Size of ' + db_name() + ' LOG is ' + Q(v*I&k
CONVERT(VARCHAR(30),size) + ' 8K pages or ' +
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CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' D>tex/Of3
FROM sysfiles ,5}%_
WHERE name = @LogicalFileName @p`*MWU
DROP TABLE DummyTrans fNR2(8;}
SET NOCOUNT OFF } )DE
8、说明:更改某个表 ZcJa:
exec sp_changeobjectowner 'tablename','dbo' G*;?&;*
9、存储更改全部表 wJc~AP)I%z
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch [0vgA#6I
@OldOwner as NVARCHAR(128), pUbf]3 t
@NewOwner as NVARCHAR(128) L_4c~4
AS ; '6`hZ
DECLARE @Name as NVARCHAR(128) WEy$SN+P
DECLARE @Owner as NVARCHAR(128) {3,_i66
DECLARE @OwnerName as NVARCHAR(128) 0Va+l)F
DECLARE curObject CURSOR FOR ZAATV+Z
select 'Name' = name, DzZEn]+zt
'Owner' = user_name(uid) 4mHR+SZy
from sysobjects !@>_5p>q*
where user_name(uid)=@OldOwner Vx'82CIC
order by name b;Nm$`2
OPEN curObject U-^qVlw
FETCH NEXT FROM curObject INTO @Name, @Owner vVvx g0
WHILE(@@FETCH_STATUS=0) _{Z!$q6,
BEGIN `Xs3^FJt
if @Owner=@OldOwner a
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begin lL8pIcQW
set @OwnerName = @OldOwner + '.' + rtrim(@Name) rK` x<
exec sp_changeobjectowner @OwnerName, @NewOwner P ?^h
end SXqWq
-- select @name,@NewOwner,@OldOwner FR*CiaD1
FETCH NEXT FROM curObject INTO @Name, @Owner &~4;HjS
END yV"k:_O{
close curObject r_R(kns
deallocate curObject pg<m0g@W*;
GO D;?cf+6$
10、SQL SERVER中直接循环写入数据 0FN;^hP5|
declare @i int tL#~U2K
set @i=1 _\"2Mdk`]
while @i<30 _PPZ!r(
begin da[=d*I.
insert into test (userid) values(@i) qStZW^lFeY
set @i=@i+1 8-#_xsZ^;
end ov3FKMG?
小记存储过程中经常用到的本周,本月,本年函数 PI G3kJ
Dateadd(wk,datediff(wk,0,getdate()),-1) nm#ISueh
Dateadd(wk,datediff(wk,0,getdate()),6) y
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Dateadd(mm,datediff(mm,0,getdate()),0) 1R-1#<a>&
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) IvZ,|R?
Dateadd(yy,datediff(yy,0,getdate()),0) p]jkfsCjN
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) @ra^0
上面的SQL代码只是一个时间段 1>yh`Bp\=
Dateadd(wk,datediff(wk,0,getdate()),-1) hZZ
Dateadd(wk,datediff(wk,0,getdate()),6) 5S9i>B
就是表示本周时间段. kh4., \'
下面的SQL的条件部分,就是查询时间段在本周范围内的: e:9s%|]T
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) ^uiQZ%;
而在存储过程中 P^3`znq{
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) H|\@[:A+
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) Fok%