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。 1+x"
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一、基础 Ed9Uw7
1、说明:创建数据库 PVCoXOqh
CREATE DATABASE database-name @R[{
2、说明:删除数据库 P6:C/B
drop database dbname OviS(}v4@
3、说明:备份sql server )kD/ 8
--- 创建 备份数据的 device AYts
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USE master isQ(O
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 'YL[s
--- 开始 备份 ~3&{`9Y
BACKUP DATABASE pubs TO testBack *3GV9'-P
4、说明:创建新表 ~4~`bT9
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) yYG<tUG;
根据已有的表创建新表: .w2 ID
A:create table tab_new like tab_old (使用旧表创建新表) h!EA;2yGKa
B:create table tab_new as select col1,col2... from tab_old definition only tq3Wga!5
5、说明:删除新表 FcDS*ZEk!
drop table tabname 8t-GsjHb
6、说明:增加一个列 drq3=2
Alter table tabname add column col type ]R__$fl`8
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 )pnyVTKt
7、说明:添加主键: Alter table tabname add primary key(col) +&EXTZ@o
说明:删除主键: Alter table tabname drop primary key(col) %Tm*^
8、说明:创建索引:create [unique] index idxname on tabname(col....) M+/xw8}a
删除索引:drop index idxname 5(1:^:LGK
注:索引是不可更改的,想更改必须删除重新建。 -3 I3 X
9、说明:创建视图:create view viewname as select statement M^FY6TT4O
删除视图:drop view viewname c`;\sW-_W
10、说明:几个简单的基本的sql语句 zzqJeIS
选择:select * from table1 where 范围 Uzu6>yT
插入:insert into table1(field1,field2) values(value1,value2) d$dy6{/YD
删除:delete from table1 where 范围 ahBqYAK9
更新:update table1 set field1=value1 where 范围 V$^jlWdR
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! ]-fkmnmWX
排序:select * from table1 order by field1,field2 [desc] %,$ n^{v
总数:select count as totalcount from table1 m>>.N?
求和:select sum(field1) as sumvalue from table1 JAPr[O&
平均:select avg(field1) as avgvalue from table1 \;LDE`Q_x
最大:select max(field1) as maxvalue from table1 L4#pMc
最小:select min(field1) as minvalue from table1 *H>rvE.K?
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11、说明:几个高级查询运算词 ).k DY?s
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A: UNION 运算符 Cs'LrUB?=U
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。 ZL MH~cc
B: EXCEPT 运算符
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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。 nwRltK
C: INTERSECT 运算符 7e/+C{3v
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。 [K!9xM6
注:使用运算词的几个查询结果行必须是一致的。 Gr"CHz/
12、说明:使用外连接 op,L3:R\Z
A、left outer join: 8[^'PIz
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。 o4(*nz
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 N.F5)04
B:right outer join: JKfG/z|
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。 APQq F/
C:full outer join: -%K!Ra\W
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。 jmok]-pC
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二、提升 /zn=AAYb
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) o5<<vvdA
法一:select * into b from a where 1<>1 '%)R}wgV
法二:select top 0 * into b from a nla6QlFYn*
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) [}RoZB&I
insert into b(a, b, c) select d,e,f from b; Z:;}
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) 9>""xt
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 6_LeP9s )
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. bS.w<V
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4、说明:子查询(表名1:a 表名2:b) DSGcxM+
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) )G? qX.D
5、说明:显示文章、提交人和最后回复时间 d_RgKdR )k
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b >t D=t8
6、说明:外连接查询(表名1:a 表名2:b) aQkOQy
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c =W(*0"RM
7、说明:在线视图查询(表名1:a ) B5e9'X^
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select * from (SELECT a,b,c FROM a) T where t.a > 1; p6VD*PT$&
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 4ls:BO;k]
select * from table1 where time between time1 and time2 *6uccx7{
select a,b,c, from table1 where a not between 数值1 and 数值2 WzMYRKZ
9、说明:in 的使用方法 5En6f`nR{
select * from table1 where a [not] in ('值1','值2','值4','值6') gr=h!'m
10、说明:两张关联表,删除主表中已经在副表中没有的信息 %x)bZ=An
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) s?SspuV
11、说明:四表联查问题: x 3@-E
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... b}J%4Lx%m
12、说明:日程安排提前五分钟提醒 4#U}bN
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 `]Bb0h1![
13、说明:一条sql 语句搞定数据库分页 R[WiW RfD
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 |"H 2'L$
14、说明:前10条记录 2wf&jGHs
select top 10 * form table1 where 范围 2[E wN!IZ
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.) <v"o+
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) !e$gp(4
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 3} A$+PX
(select a from tableA ) except (select a from tableB) except (select a from tableC) /
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17、说明:随机取出10条数据 +)]YvZ6%[,
select top 10 * from tablename order by newid() $YYWpeW
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18、说明:随机选择记录 <hT\xBb:
select newid() c:R?da
19、说明:删除重复记录 J~YT~D2L
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) "gM^o
20、说明:列出数据库里所有的表名 |HazM9=
select name from sysobjects where type='U' xO$P
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21、说明:列出表里的所有的 @hLkU4S
select name from syscolumns where id=object_id('TableName') R1jl <=
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。 pYO =pL^Q
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 \& JZ
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显示结果: qnm_#!&uHT
type vender pcs (8 nv&|
电脑 A 1 h}b:-a
电脑 A 1 xNz(LZ.c
光盘 B 2 1MelHW
光盘 A 2 UHBXq;?&q
手机 B 3 K^-1M?
手机 C 3 Io6/Fv>!
23、说明:初始化表table1 f|RmAP;X,
TRUNCATE TABLE table1 *Cy54Z#
24、说明:选择从10到15的记录 ^l &lwSRVt
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 6(
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三、技巧 J3$>~?^1
1、1=1,1=2的使用,在SQL语句组合时用的较多 ~lj~]j
"where 1=1" 是表示选择全部 "where 1=2"全部不选, 0D-`>_
如: E-LkP;
if @strWhere !='' A~ya{^}
begin sXKkZ+2q
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere lU
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end LZ*8YNp1'
else -@TY8#O#-
begin 8\"<t/_
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set @strSQL = 'select count(*) as Total from [' + @tblName + ']' ZbnAAbfKH
end f%Q)_F[0D4
我们可以直接写成 +`y(S}Z
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere +9)JtmoL
2、收缩数据库 TS<d?:
--重建索引 /-=fWtA
DBCC REINDEX XxqGsGx4
DBCC INDEXDEFRAG <}a?<):S
--收缩数据和日志 (Wzp sDte
DBCC SHRINKDB ju~$FNt8R
DBCC SHRINKFILE Gvb2>ZN
3、压缩数据库 Lp`.fn8Ln
dbcc shrinkdatabase(dbname) x`CjFaE~F
4、转移数据库给新用户以已存在用户权限 Z9{~t
exec sp_change_users_login 'update_one','newname','oldname' Hq@+m!
go Daf|.5>(@
5、检查备份集 :uL<UD,vu3
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' ;m/e|_4;y
6、修复数据库 _k84#E0
ALTER DATABASE [dvbbs] SET SINGLE_USER O&%'j
GO r924!zdbR
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK %L|fTndKH
GO U,<m%C"
ALTER DATABASE [dvbbs] SET MULTI_USER l.YE@EL
GO HB07 n4 |
7、日志清除 =C %)(|
SET NOCOUNT ON CEy\1D
DECLARE @LogicalFileName sysname, f@*69a8
@MaxMinutes INT, sqkWQ`Ur
@NewSize INT ~uQ*u.wi
USE tablename -- 要操作的数据库名 ttP7-y
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 gt kV=V
@MaxMinutes = 10, -- Limit on time allowed to wrap log. |}"YUk^
@NewSize = 1 -- 你想设定的日志文件的大小(M) kUT2/3Vi
-- Setup / initialize X2w)J?pv
DECLARE @OriginalSize int 6Yai?*.Q
SELECT @OriginalSize = size ;?h[WIy
FROM sysfiles MBLZ:A |
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WHERE name = @LogicalFileName xJq|,":gj
SELECT 'Original Size of ' + db_name() + ' LOG is ' + q8 v iC|
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + qpQ;,8X-"
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' iO L$| Z(
FROM sysfiles x6ghO-s
WHERE name = @LogicalFileName (qn=BPI
CREATE TABLE DummyTrans ~(kEGEF
(DummyColumn char (8000) not null) osV6=
DECLARE @Counter INT, yi7.9/;a
@StartTime DATETIME, q'D Ts9Bj
@TruncLog VARCHAR(255) `[ZswLE
SELECT @StartTime = GETDATE(), U%3N=M
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 6v%yU3l
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ^F^g(|(K
EXEC (@TruncLog) x#{!hL
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-- Wrap the log if necessary. 5K vp%
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired /VR~E'Cy%
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) g_>&R58
AND (@OriginalSize * 8 /1024) > @NewSize y^2#;0W
BEGIN -- Outer loop. h5?^MRZS
SELECT @Counter = 0 T"wg/mT
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) 6?Ncgj
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BEGIN -- update Om3Ayk}
INSERT DummyTrans VALUES ('Fill Log') ?kjQ_K
DELETE DummyTrans ^WA7X9ed
SELECT @Counter = @Counter + 1 F^,:p.ihm<
END $]7f1U_e
EXEC (@TruncLog) Mj0,Y#=76
END ]#0 (
SELECT 'Final Size of ' + db_name() + ' LOG is ' + +eVYy_bL-
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + l9K`+c+t
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ZL|aB886
FROM sysfiles wMS%/l0p1
WHERE name = @LogicalFileName !'f7;%7s
DROP TABLE DummyTrans q4ROuE|d
SET NOCOUNT OFF @ @[xTyA
8、说明:更改某个表 ^eW<-n@^
exec sp_changeobjectowner 'tablename','dbo' BabaKSm}LP
9、存储更改全部表 y-<.l=6A
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Nd8>p.iqO
@OldOwner as NVARCHAR(128),
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@NewOwner as NVARCHAR(128) {}$9
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AS -CPtYG[s
DECLARE @Name as NVARCHAR(128) _p$/.~Xo9
DECLARE @Owner as NVARCHAR(128) \o<ucp\J
DECLARE @OwnerName as NVARCHAR(128) W>3S%2d
DECLARE curObject CURSOR FOR -^&=I3bp
select 'Name' = name, hSehJjEoM
'Owner' = user_name(uid) <2U#U;
from sysobjects 7q0_lEh
where user_name(uid)=@OldOwner dT|XcVKg
order by name .Fb#j+Lq
OPEN curObject J 8i;E4R
FETCH NEXT FROM curObject INTO @Name, @Owner 4v[y^P
WHILE(@@FETCH_STATUS=0) _i_='dsyW/
BEGIN Cqd\n#d/~
if @Owner=@OldOwner @9/I^Zk
begin PV68d; $:8
set @OwnerName = @OldOwner + '.' + rtrim(@Name) .}faWzRH9
exec sp_changeobjectowner @OwnerName, @NewOwner x0 j5D
end P&`%VW3E
-- select @name,@NewOwner,@OldOwner v9(5HY
FETCH NEXT FROM curObject INTO @Name, @Owner RZ6y5
END rr#nBhh8
close curObject 9r%fBiSk
deallocate curObject t]K20(FSN
GO B{Q}^Mcxy
10、SQL SERVER中直接循环写入数据 <rC%$tr
declare @i int o.Kn DY
set @i=1 U[C>Aoze
while @i<30 5|*{~O|
begin d4o
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insert into test (userid) values(@i) ZP";B^J
set @i=@i+1 Ow0>qzTg
end Yp\n=#$[
小记存储过程中经常用到的本周,本月,本年函数 'LgRdtO6
Dateadd(wk,datediff(wk,0,getdate()),-1) $6Ma{r C|
Dateadd(wk,datediff(wk,0,getdate()),6) qbyYNlXqm
Dateadd(mm,datediff(mm,0,getdate()),0) \'|n.1Fr
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) p)biOG
Dateadd(yy,datediff(yy,0,getdate()),0) aoy Be|H~=
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) {4_s:+v0
上面的SQL代码只是一个时间段 Av x`
Dateadd(wk,datediff(wk,0,getdate()),-1) i'fw>-0
Dateadd(wk,datediff(wk,0,getdate()),6) Jn+ -G4h$
就是表示本周时间段. n#!c!EfG
下面的SQL的条件部分,就是查询时间段在本周范围内的: }s,NM%oI
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) #]h
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而在存储过程中 APu$t$dmm
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) -YNpHd/;,
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) i(~DhXz*T