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。 wyWe2d
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一、基础 sa6/$
1、说明:创建数据库 4OX|pa
CREATE DATABASE database-name TC[(mf:8
2、说明:删除数据库 "Bn8WT2?
drop database dbname &q8oalh
3、说明:备份sql server Y]MB/\gj
--- 创建 备份数据的 device d7(g=JK<
USE master uknX py))
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' &gGh%:`B
--- 开始 备份 0G?*i_u\
BACKUP DATABASE pubs TO testBack +h*-9
4、说明:创建新表 EH1GdlhA
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) @s7ZfV??
根据已有的表创建新表: rx[l7F
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A:create table tab_new like tab_old (使用旧表创建新表) <KB V
B:create table tab_new as select col1,col2... from tab_old definition only GS_+KR\
5、说明:删除新表 tE=;V) %we
drop table tabname )w/ #T
6、说明:增加一个列 3(&f!<Uy
Alter table tabname add column col type <cig^B{nX
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。 _TLB1T^/4
7、说明:添加主键: Alter table tabname add primary key(col) ArK%?*`5
说明:删除主键: Alter table tabname drop primary key(col) *BdKQ/Dk
8、说明:创建索引:create [unique] index idxname on tabname(col....) 0i|z$QRL~
删除索引:drop index idxname TjDDvXY
注:索引是不可更改的,想更改必须删除重新建。 _`|te|ccF
9、说明:创建视图:create view viewname as select statement MuI>ZoNF
删除视图:drop view viewname #^FDG1=
10、说明:几个简单的基本的sql语句 Q6qIx=c4
选择:select * from table1 where 范围 {"e)Jj_=
插入:insert into table1(field1,field2) values(value1,value2) V7~tIhuJH
删除:delete from table1 where 范围 =o_Ua^mr
更新:update table1 set field1=value1 where 范围 ;YGCsLT<xt
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! R V@'$`Q
排序:select * from table1 order by field1,field2 [desc] ,76xa%k(U|
总数:select count as totalcount from table1 L'A9TW2
求和:select sum(field1) as sumvalue from table1 }Zuk}Og9+
平均:select avg(field1) as avgvalue from table1 {~*^jS']5
最大:select max(field1) as maxvalue from table1 Ij w{g%
最小:select min(field1) as minvalue from table1 @*>kOZ(3
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11、说明:几个高级查询运算词 YmwUl> @{
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A: UNION 运算符 B
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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。 (D5sJ$&E@\
B: EXCEPT 运算符 cVb&Jzd
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 b aO^Z
C: INTERSECT 运算符 UA0j#
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 .Tm m
注:使用运算词的几个查询结果行必须是一致的。 t@"i/@8x$
12、说明:使用外连接 arWP]%E0W
A、left outer join: s^\
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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。 A.YXK%A%
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 E&z`BPd
B:right outer join: Vf*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。 or<n[<D-C
C:full outer join: 3bU(ea^e$
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。 w ag^Sk
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二、提升 WPu-P
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) yw@kh^L
法一:select * into b from a where 1<>1 Q# Yba
法二:select top 0 * into b from a aTWCX${~b
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) w!kWG,{C
insert into b(a, b, c) select d,e,f from b; x9!3i{_
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) {r>iUgg
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 j0wpaIp
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. |d)*,O4s
4、说明:子查询(表名1:a 表名2:b) Q4R*yRk
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) QKB*N)%6
5、说明:显示文章、提交人和最后回复时间 T1~G{@"
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b E:$EK_?:t
6、说明:外连接查询(表名1:a 表名2:b) Y W9+.Dc`
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c hj4mbL
7、说明:在线视图查询(表名1:a ) F$6JzF$|F
select * from (SELECT a,b,c FROM a) T where t.a > 1; Mil+> X0
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 ~[@gu,Wb
select * from table1 where time between time1 and time2 Ip_deP@
select a,b,c, from table1 where a not between 数值1 and 数值2 GZt L-
9、说明:in 的使用方法 OaH1xZNOC`
select * from table1 where a [not] in ('值1','值2','值4','值6') ?:AD&Dn
10、说明:两张关联表,删除主表中已经在副表中没有的信息 qG)M8xk
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) yQz6K6p
11、说明:四表联查问题: ;Pw\p^wz
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 ..... $p;<1+!
12、说明:日程安排提前五分钟提醒 :3N&&]
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 p!Xn iY
13、说明:一条sql 语句搞定数据库分页 QWQJSz5
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 umo<9Y
14、说明:前10条记录 eYQPK?jo
select top 10 * form table1 where 范围 *ufVZzP(
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.) o|cx?
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) Cm"7f!(#
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 oniVC',
(select a from tableA ) except (select a from tableB) except (select a from tableC) Jk=_8Xvr`
17、说明:随机取出10条数据 ^:cc3wt'3[
select top 10 * from tablename order by newid() nRHxbE}::
18、说明:随机选择记录 VV+gPC
select newid() x O_u
19、说明:删除重复记录 uvMcB9
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ZJf:a}=h
20、说明:列出数据库里所有的表名 Z#NEa.]
select name from sysobjects where type='U' sS{!z@\Lf
21、说明:列出表里的所有的 :9~LYJ
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select name from syscolumns where id=object_id('TableName') E'
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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。 `i5 \(cdl
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 MLT^7'y
显示结果: UP .4# 1I
type vender pcs r
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电脑 A 1 IY"+hHt
电脑 A 1 UFzC8
光盘 B 2 `UD,ne
光盘 A 2 =@ d/SZ|(E
手机 B 3 or
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手机 C 3 uA[c$tBe
23、说明:初始化表table1 H3>49;`
TRUNCATE TABLE table1 90Bn}@t=Q
24、说明:选择从10到15的记录 IgyoBfj\d
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 5q,ZH6\
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三、技巧 H8!)zZ
1、1=1,1=2的使用,在SQL语句组合时用的较多 5"9'=LV~
"where 1=1" 是表示选择全部 "where 1=2"全部不选, OK" fFv
如: nKnQ%R
if @strWhere !='' G0Y]-*1
begin ^xX1G_{
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere N;` jz(r
end U
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else N`J]k
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begin gp<XTLJ@>
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' {!&^VXZIT
end L_sDbAT~<
我们可以直接写成 Y !%2vOt
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere hw({>cH\
2、收缩数据库 Q2 Dh(
--重建索引 S|
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DBCC REINDEX eb>jT:
DBCC INDEXDEFRAG lOy1vw'
--收缩数据和日志 <nU8.?\?~
DBCC SHRINKDB | Di7,$c
DBCC SHRINKFILE y>>)Yo&|
3、压缩数据库 *cP(3n3]R
dbcc shrinkdatabase(dbname) Aa+<4
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4、转移数据库给新用户以已存在用户权限 kx,3[qe'S
exec sp_change_users_login 'update_one','newname','oldname' %v4*$E!f
go DX_?-jw})f
5、检查备份集 VA5f+c/ %
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' WBWIHv{j
6、修复数据库 1hY%ZsjC
ALTER DATABASE [dvbbs] SET SINGLE_USER &~:+2
GO d7G
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DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK Q9Vj8JO"{
GO _BoYyJQH
ALTER DATABASE [dvbbs] SET MULTI_USER _<%YLv
GO /'a\$G"%6
7、日志清除 w0X})&,{`m
SET NOCOUNT ON FQ"ED:lks
DECLARE @LogicalFileName sysname, = N^Ec[u(l
@MaxMinutes INT, 4rLc]
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@NewSize INT #T=e p0
USE tablename -- 要操作的数据库名 .hRtQU
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 Dkg^B@5Xr
@MaxMinutes = 10, -- Limit on time allowed to wrap log. M%Zh{
@NewSize = 1 -- 你想设定的日志文件的大小(M) A|(!\J0
-- Setup / initialize 39~te%;C7
DECLARE @OriginalSize int BtrMv6
SELECT @OriginalSize = size @E4ya$A)F
FROM sysfiles Q`!^EyRA:^
WHERE name = @LogicalFileName ~t1?oJ
SELECT 'Original Size of ' + db_name() + ' LOG is ' + DQ@M?~1hp
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + EXsVZg"#
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' BvS!P8
FROM sysfiles NJCSo(O
WHERE name = @LogicalFileName &2nICAN[
CREATE TABLE DummyTrans L[^.pO
(DummyColumn char (8000) not null) y@(EGfI
DECLARE @Counter INT, /r8sL)D+
@StartTime DATETIME, ^^g u
@TruncLog VARCHAR(255) 4Uhh]/
SELECT @StartTime = GETDATE(), h_Ssm{C\
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' t?H
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) mNlbiB
EXEC (@TruncLog) TBZhL
-- Wrap the log if necessary. R*?!xDJ
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired '~VF*i^4
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) rZ&li/Z
AND (@OriginalSize * 8 /1024) > @NewSize "E@A~<RKP
BEGIN -- Outer loop. z31g"
SELECT @Counter = 0 nRyx2\Py+
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) y eam-8
BEGIN -- update ,Jx.Kj.,
INSERT DummyTrans VALUES ('Fill Log') Pk;1q?tGw
DELETE DummyTrans w"O{@2B3:H
SELECT @Counter = @Counter + 1 ^{YK'60
END {v"Y!/
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EXEC (@TruncLog)
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END }USOWsLSt
SELECT 'Final Size of ' + db_name() + ' LOG is ' + DVt^O[
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + D`fIw`
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CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' D!8v$(#hR
FROM sysfiles Uz=ol.E
WHERE name = @LogicalFileName 22*~CIh~x
DROP TABLE DummyTrans xiV!\Z}
SET NOCOUNT OFF T 0qM"
8、说明:更改某个表 caxOxRo\
exec sp_changeobjectowner 'tablename','dbo' $pIo`F _W
9、存储更改全部表 +6x}yc:yd
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch +,Or^pO=
@OldOwner as NVARCHAR(128), dsOt(yNo
@NewOwner as NVARCHAR(128) _U9.u#>sV
AS Z_a@,k:+[
DECLARE @Name as NVARCHAR(128) >S8
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DECLARE @Owner as NVARCHAR(128) b 4f3ef
DECLARE @OwnerName as NVARCHAR(128) -q(*)N5.2
DECLARE curObject CURSOR FOR 9fWR8iV
select 'Name' = name, h8 FV2"
'Owner' = user_name(uid) >2F9Tz,3
from sysobjects =?_:h`}
where user_name(uid)=@OldOwner gtIEpYN+
order by name sm{/S*3
OPEN curObject j'OXT<n*
FETCH NEXT FROM curObject INTO @Name, @Owner At'M? Q@v
WHILE(@@FETCH_STATUS=0) $3gM P+
BEGIN "<Yxt"Z4
if @Owner=@OldOwner <g&.U W4
begin ,g4T>7`&U%
set @OwnerName = @OldOwner + '.' + rtrim(@Name) }=B~n0
exec sp_changeobjectowner @OwnerName, @NewOwner m.<or?l'y>
end j{johV+`8
-- select @name,@NewOwner,@OldOwner %<r}V<OeR
FETCH NEXT FROM curObject INTO @Name, @Owner <m0=bm{j
END E@6gTx*
close curObject a|(|!=
deallocate curObject 5A^8?,F@
GO $inKI
10、SQL SERVER中直接循环写入数据 j\NCoos
declare @i int B)/c]"@89
set @i=1 Mf !S'\
while @i<30 f@q.kD21
begin v2a(yH
insert into test (userid) values(@i) +_25E.>ml
set @i=@i+1 KdD~;Ap$
end 138v{Z
小记存储过程中经常用到的本周,本月,本年函数 I_e7rE0`
Dateadd(wk,datediff(wk,0,getdate()),-1) s IBP$9
Dateadd(wk,datediff(wk,0,getdate()),6) n]7rHV}G
Dateadd(mm,datediff(mm,0,getdate()),0) DMTc{
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) q#1G4l.
Dateadd(yy,datediff(yy,0,getdate()),0) R;fe v
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Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) hL&7D@
上面的SQL代码只是一个时间段 Vk*XiEfKm>
Dateadd(wk,datediff(wk,0,getdate()),-1) s>1\bio*I
Dateadd(wk,datediff(wk,0,getdate()),6) `GlOl-
就是表示本周时间段. !? H:?
下面的SQL的条件部分,就是查询时间段在本周范围内的: !1K.HdK
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) NJmx(!Xsh
而在存储过程中 vE1:;%Q
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 45x4JG
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ROvY,-?