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。 .so{ RI
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一、基础 88U4I
1、说明:创建数据库 |7/B20
CREATE DATABASE database-name -i'T!Qg1
2、说明:删除数据库 /)de`k"
drop database dbname 7Yxy2[
3、说明:备份sql server d#a
--- 创建 备份数据的 device Ik1,?A
USE master h{sW$WA
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 2ezuP F
--- 开始 备份 KF'H|)!K
BACKUP DATABASE pubs TO testBack *4qsM,t
4、说明:创建新表 -H`G6oMOO
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) .KT+,Y
根据已有的表创建新表: c)SSi@<
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A:create table tab_new like tab_old (使用旧表创建新表) ?/)5U}*M0T
B:create table tab_new as select col1,col2... from tab_old definition only =,[46 ;q
5、说明:删除新表 4_N)1u !
drop table tabname ja7Zv[
6、说明:增加一个列 %TG$5')0
Alter table tabname add column col type 0 \LkJ*i
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。 =pcj{B{qa
7、说明:添加主键: Alter table tabname add primary key(col) >Fld7;L?<
说明:删除主键: Alter table tabname drop primary key(col) Mn~A;=%qF
8、说明:创建索引:create [unique] index idxname on tabname(col....) 7Nwi\#o
删除索引:drop index idxname 0v0Y(
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注:索引是不可更改的,想更改必须删除重新建。 >W'SG3Hmc
9、说明:创建视图:create view viewname as select statement 2c%}p0<;|?
删除视图:drop view viewname ,0 &lag
10、说明:几个简单的基本的sql语句 :/%Vpdd@
选择:select * from table1 where 范围 ^MJGY,r6b
插入:insert into table1(field1,field2) values(value1,value2) hCT%1R}rKr
删除:delete from table1 where 范围 |7`Vw Z
更新:update table1 set field1=value1 where 范围
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查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! Z{p6Q1u
排序:select * from table1 order by field1,field2 [desc] Sc6wC H
总数:select count as totalcount from table1 X=\#n-*
求和:select sum(field1) as sumvalue from table1 yekIw
平均:select avg(field1) as avgvalue from table1 I I>2\d|
最大:select max(field1) as maxvalue from table1 \ @N> 38M
最小:select min(field1) as minvalue from table1 P>@`hZ9
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11、说明:几个高级查询运算词 1~ SY
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A: UNION 运算符 ;7`<.y
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。 g=Qga09
B: EXCEPT 运算符 z{#F9'\&
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。 Y[~6f,?^
C: INTERSECT 运算符 zW0AB8l
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。 &vMH
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注:使用运算词的几个查询结果行必须是一致的。 INbjk;k
12、说明:使用外连接 m]-8?B1`Y
A、left outer join: Y6L+3*Qt
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。 Jl]]nOBQ/
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 km c9P&
B:right outer join: u=E?N:I~F
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。 [V)sCAW
C:full outer join: h{* O9O<
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。 p fBO5Ys
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二、提升 Gr6ma*)y~t
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) !7xp<=
法一:select * into b from a where 1<>1 Ox~'w0c,f
法二:select top 0 * into b from a T![K
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) z}Z`kq+C
insert into b(a, b, c) select d,e,f from b; 4|$D.`Wu
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) `90v~OF
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 tJwF
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例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. @&Nvb.5nT
4、说明:子查询(表名1:a 表名2:b) @Qs-A^.
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) GwW#Ww;Oc
5、说明:显示文章、提交人和最后回复时间 kQ#eWk J,
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 4C*3#/TR
6、说明:外连接查询(表名1:a 表名2:b) `>sqP aD
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c DYWC]*
7、说明:在线视图查询(表名1:a ) 42wcpSp
select * from (SELECT a,b,c FROM a) T where t.a > 1; EkL\~^
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 W1@;94Sb~
select * from table1 where time between time1 and time2 X#3<hN*v
select a,b,c, from table1 where a not between 数值1 and 数值2 `U g.c
9、说明:in 的使用方法 87^
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select * from table1 where a [not] in ('值1','值2','值4','值6') Agi1r]W
10、说明:两张关联表,删除主表中已经在副表中没有的信息 R{[Q+y'E
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) "T&uS1+=c
11、说明:四表联查问题: Y=rr6/k
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 ..... 0&.lSwa
12、说明:日程安排提前五分钟提醒 Qi[D&47XO
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 vv0zUvmT
13、说明:一条sql 语句搞定数据库分页 Hxl,U>za#
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 DrEtnt
14、说明:前10条记录 epbp9[`
select top 10 * form table1 where 范围 >o} ati
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.) ;Bb5KD
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) vUK>4^{J5
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 <kSaSW
(select a from tableA ) except (select a from tableB) except (select a from tableC) h]Oplp4\W
17、说明:随机取出10条数据 w3w*"M
select top 10 * from tablename order by newid() # 0!IUSa
18、说明:随机选择记录 "B}08C,?
select newid() O0{
19、说明:删除重复记录 0l6iv[qu5w
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) /K!,^Xn
20、说明:列出数据库里所有的表名 pHvE`s"Ea
select name from sysobjects where type='U' vQ/\BN
21、说明:列出表里的所有的 *_QHtZG
select name from syscolumns where id=object_id('TableName') |d5L
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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。 -{*V)J_Co
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 DXz8C -
显示结果: /a(zLHyz)
type vender pcs e\_6/j7'
电脑 A 1 BP[U`
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电脑 A 1 .V3Dql@z"
光盘 B 2 be/1-=m
光盘 A 2 I.u,f:Fl'
手机 B 3 3rY /6{
手机 C 3 D%idlL2%J
23、说明:初始化表table1 >>bYg
TRUNCATE TABLE table1 oPy zk7{
24、说明:选择从10到15的记录 8@aS9th$
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Rdg0WT*;j
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三、技巧 ~|9LWp_
1、1=1,1=2的使用,在SQL语句组合时用的较多 tKeO+6 l
"where 1=1" 是表示选择全部 "where 1=2"全部不选, Qg>GW
如: j_yFH#^W:
if @strWhere !='' y:OywIi(
begin W{+0iAYnp
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere &&]!+fTZ\(
end $M`;."
else ++!E9GU{
begin 'TrrOq4
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' G
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end YB{E=\~
我们可以直接写成 mY8=qkZE
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere JX)z<Dz$
2、收缩数据库 Cj1UD;
--重建索引 B^(rUR
DBCC REINDEX *wB-lg7%
DBCC INDEXDEFRAG ,A!e"=HF
--收缩数据和日志 MJ9SsC1
DBCC SHRINKDB W79A4l<
DBCC SHRINKFILE c'+r[rSn1
3、压缩数据库 ^Ai_/! "
dbcc shrinkdatabase(dbname) .r| vz6tU?
4、转移数据库给新用户以已存在用户权限 &E &iaw!
exec sp_change_users_login 'update_one','newname','oldname' GLQvAHC
go ]GtR8w@w
5、检查备份集 =Xjuz:9D~
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' r)5\3j[P
6、修复数据库 '(pdk
ALTER DATABASE [dvbbs] SET SINGLE_USER d+2O^of:T
GO H8BO*8}
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 7oe@bS/Z
GO M y"!j,Up
ALTER DATABASE [dvbbs] SET MULTI_USER .(1j!B4^
GO 0^&R7Rv c
7、日志清除 ).!14Gjo
SET NOCOUNT ON @
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DECLARE @LogicalFileName sysname, pu$XUt
@MaxMinutes INT, m=iov2K>
@NewSize INT y [9}[NMZ
USE tablename -- 要操作的数据库名 06@0r
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 To8v#.i
@MaxMinutes = 10, -- Limit on time allowed to wrap log. }Q=se[((
@NewSize = 1 -- 你想设定的日志文件的大小(M) Zc3:9
-- Setup / initialize 5652'p
DECLARE @OriginalSize int Z^`=!n-V
SELECT @OriginalSize = size g}
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FROM sysfiles 4Eh BpTg
WHERE name = @LogicalFileName :$cSQ(q9a
SELECT 'Original Size of ' + db_name() + ' LOG is ' + a H|OA\<
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + K@sP~('
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' _{`'{u
FROM sysfiles ]AC!R{H
WHERE name = @LogicalFileName u1|P'>;lF
CREATE TABLE DummyTrans e=]oh$]
(DummyColumn char (8000) not null) h NOYFH
DECLARE @Counter INT, "4k=(R?
@StartTime DATETIME, ckjVa\
@TruncLog VARCHAR(255) %M)oHX1p
SELECT @StartTime = GETDATE(), Cb%.C;q
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' Bd oC6H
DBCC SHRINKFILE (@LogicalFileName, @NewSize) v*'iWHCl,
EXEC (@TruncLog) "p~]m~g
-- Wrap the log if necessary. S7NnC4)=-f
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired BQuliX&
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) zj$_iB`9
AND (@OriginalSize * 8 /1024) > @NewSize
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BEGIN -- Outer loop. gjegzKU
SELECT @Counter = 0 Y\g90
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) rI^~9Rz
BEGIN -- update aC8,Y$>?E`
INSERT DummyTrans VALUES ('Fill Log') N]s7/s
DELETE DummyTrans vzyI::f?
SELECT @Counter = @Counter + 1 !Ir1qt8T
END .f !]@"\
EXEC (@TruncLog) 7z&adkG:
END -90ZI1O`
SELECT 'Final Size of ' + db_name() + ' LOG is ' + F%_,]^ n[
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + Z:o
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CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' Vi?~0.Z%
FROM sysfiles 2.Eu+*UC
WHERE name = @LogicalFileName kJvy<(iG
DROP TABLE DummyTrans ok>P [
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SET NOCOUNT OFF `m@]
8、说明:更改某个表 lGnql 1(
exec sp_changeobjectowner 'tablename','dbo' ,'1Olu{v[s
9、存储更改全部表 a._^E/EV
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch 1^60I#Vr@
@OldOwner as NVARCHAR(128), W]!@Zlal
@NewOwner as NVARCHAR(128) ,+NE: _
AS cdJ`Gk
DECLARE @Name as NVARCHAR(128) -M1~iOb
DECLARE @Owner as NVARCHAR(128) r8
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DECLARE @OwnerName as NVARCHAR(128) x^#6>oOR
DECLARE curObject CURSOR FOR -l40)^ E}
select 'Name' = name, dp
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'Owner' = user_name(uid) LA;V}%y?
from sysobjects Xv-1PY':pA
where user_name(uid)=@OldOwner UE&C
order by name v`_i1h9p{
OPEN curObject .e FOfV)
FETCH NEXT FROM curObject INTO @Name, @Owner iFwyh`Bcg
WHILE(@@FETCH_STATUS=0) YM`:L
BEGIN #GY&$8.u*
if @Owner=@OldOwner ezg^5o;
begin p'Y&Z?8
set @OwnerName = @OldOwner + '.' + rtrim(@Name) (ifqwl62
exec sp_changeobjectowner @OwnerName, @NewOwner FD
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end G>[
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-- select @name,@NewOwner,@OldOwner qr'x0r|<>
FETCH NEXT FROM curObject INTO @Name, @Owner ! =\DC,-CB
END s#+"5&!s
close curObject _d\u!giy
deallocate curObject C"U[ b%
GO ;*wT,2;
10、SQL SERVER中直接循环写入数据 <*A|pns
declare @i int `bZ2x@
set @i=1 :tjgg]
while @i<30 409x!d~it
begin E~<(i':
insert into test (userid) values(@i)
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set @i=@i+1 7z/(V\9B
end +(=0CA0GE
小记存储过程中经常用到的本周,本月,本年函数 Qc&-\kQ:$u
Dateadd(wk,datediff(wk,0,getdate()),-1) *w'q
Dateadd(wk,datediff(wk,0,getdate()),6) Q3NPwM
Dateadd(mm,datediff(mm,0,getdate()),0) DnG/ n
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) &O+sK4P
Dateadd(yy,datediff(yy,0,getdate()),0) 6Q.{llO
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) ,c,Xd
上面的SQL代码只是一个时间段 RV0>-@/x
Dateadd(wk,datediff(wk,0,getdate()),-1) z)58\rtz
Dateadd(wk,datediff(wk,0,getdate()),6) H-/; l54E
就是表示本周时间段. 7d|*postv
下面的SQL的条件部分,就是查询时间段在本周范围内的: K9e~Wl<3
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 2Y E;m&
而在存储过程中 4T-,'P{?
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) KMxNH,5
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) 2~G,Ia