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。 -y.cy'$f
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一、基础 1I%u)[;>
1、说明:创建数据库 f:-)S8OJ
CREATE DATABASE database-name eo+<@83
2、说明:删除数据库 /WQ.,a
drop database dbname 7xnj\9$m
3、说明:备份sql server o\8?CNm1(
--- 创建 备份数据的 device R3B+vLGX
USE master ysnW3q!@
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 6]7csOE
--- 开始 备份 UytMnJ88
BACKUP DATABASE pubs TO testBack 56AC%_ g>
4、说明:创建新表 4 OPY
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) rC8p!e.yL
根据已有的表创建新表: B&cIx~+
A:create table tab_new like tab_old (使用旧表创建新表) +M"j#H
B:create table tab_new as select col1,col2... from tab_old definition only *OLqr/ yb
5、说明:删除新表 1Q@]b_"Xh
drop table tabname kmC@\xTp
6、说明:增加一个列 /1OCK=
Alter table tabname add column col type c~<;}ve^z
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。 J&8KIOz14Z
7、说明:添加主键: Alter table tabname add primary key(col) -,8LL@_
说明:删除主键: Alter table tabname drop primary key(col)
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8、说明:创建索引:create [unique] index idxname on tabname(col....) SAP/jD$5]>
删除索引:drop index idxname N{%7OG
注:索引是不可更改的,想更改必须删除重新建。 8'PZA,CW
9、说明:创建视图:create view viewname as select statement fo ~uI(rk
删除视图:drop view viewname wm~7`&
10、说明:几个简单的基本的sql语句 |62` {+
选择:select * from table1 where 范围 V'vWz`#
插入:insert into table1(field1,field2) values(value1,value2) `'1g>Ebk0
删除:delete from table1 where 范围 d]DV\*v
更新:update table1 set field1=value1 where 范围 |5 V0_79
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! y[m,t}gi
排序:select * from table1 order by field1,field2 [desc] ` aVp#
总数:select count as totalcount from table1 d{YvdN9d
求和:select sum(field1) as sumvalue from table1 >jt2vU@t.
平均:select avg(field1) as avgvalue from table1 i$NlS}W
最大:select max(field1) as maxvalue from table1
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最小:select min(field1) as minvalue from table1 NW1 Jr/
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11、说明:几个高级查询运算词 PYCN3s#Gi
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A: UNION 运算符 Sgi`&;PF
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。 >V6t
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B: EXCEPT 运算符 ?c#s}IH
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。 %#2$B+
C: INTERSECT 运算符 IR-n:z
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。 $cSUB
注:使用运算词的几个查询结果行必须是一致的。 g<Z :`00|
12、说明:使用外连接 3"x_Y
A、left outer join: neFwxS?
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。 3-/|G-4k7
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 Go%Z^pF3CO
B:right outer join: pwFdfp
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。 JX&U?Z
C:full outer join: |^Iox0A
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。 :9hGL
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二、提升 Ja6 KO2}p
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 6*Z7JiQ0
法一:select * into b from a where 1<>1 .lcp5D[(
法二:select top 0 * into b from a t'eaR-
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) Wk[a|>
insert into b(a, b, c) select d,e,f from b; BgXZr,?
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) Wj.t4XG!
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 \B#tB?rA
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. &l+Qn'N
4、说明:子查询(表名1:a 表名2:b) ]Q"T8drL
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) @_do<'a
5、说明:显示文章、提交人和最后回复时间 }#^Cj;
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b CzBYH
6、说明:外连接查询(表名1:a 表名2:b) ;+~5XLk
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c .`IhxE~mN
7、说明:在线视图查询(表名1:a ) Em!- W5*s
select * from (SELECT a,b,c FROM a) T where t.a > 1; E&8Nh J
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 i)x0]XF
select * from table1 where time between time1 and time2 \HO)ss)"
select a,b,c, from table1 where a not between 数值1 and 数值2 VukbvBWPN
9、说明:in 的使用方法 9VW/Af
select * from table1 where a [not] in ('值1','值2','值4','值6') Cfi4~ &
10、说明:两张关联表,删除主表中已经在副表中没有的信息 xeF>"6\
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) FtTq*[a
11、说明:四表联查问题: Pxl, "
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 ..... ~9]vd|
12、说明:日程安排提前五分钟提醒 J.UNw8z
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 cM%?Ot,mK"
13、说明:一条sql 语句搞定数据库分页 &@6xu{o
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 {8.Zb NEJ
14、说明:前10条记录 5{HF'1XgZ*
select top 10 * form table1 where 范围 M@T{uo
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.) FGn"j@m0
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) TJv .T2|
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 %2:UsI
(select a from tableA ) except (select a from tableB) except (select a from tableC) <6(0ZO%,C!
17、说明:随机取出10条数据 s",Ea*
select top 10 * from tablename order by newid() {YiMd
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18、说明:随机选择记录 2/+~h(Cc
select newid() JL,Y9G*]s
19、说明:删除重复记录 Z Qlk 5
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) .'`aX
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20、说明:列出数据库里所有的表名 XHA|v^
select name from sysobjects where type='U' qiet<F
21、说明:列出表里的所有的 2B4.o*Q\
select name from syscolumns where id=object_id('TableName') TyV~2pcN
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。 L!:NL#M
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 :|(YlNUv
显示结果: k<1i.rh
type vender pcs 2{j$1EdI@-
电脑 A 1 L]MWdD
电脑 A 1 K^!#;,0
光盘 B 2 W/UA%We3+L
光盘 A 2 0m3hL~0(a
手机 B 3 $TK*w8@:
手机 C 3 z6w'XA1_+t
23、说明:初始化表table1 "" UyfC[
TRUNCATE TABLE table1 !Q"L)%)'A
24、说明:选择从10到15的记录 -Y524
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc 6 ZRc|ZQ
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三、技巧 )<HvIr(xr
1、1=1,1=2的使用,在SQL语句组合时用的较多 :WRD<D_4
"where 1=1" 是表示选择全部 "where 1=2"全部不选, uzxwJs'fz
如: 1{M?_~g4
if @strWhere !='' y CHOg
begin waMV6w)<
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere i1x4$}
end pT=^o
else [.>=>KJ_
begin !BVCuuM>w
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' 'TYO-'aC
end -n7@r
我们可以直接写成 lq.:/_m0
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere fDDpR=
2、收缩数据库 d3z nb@7
--重建索引 ovN3.0tAI
DBCC REINDEX HsYzIQLL
DBCC INDEXDEFRAG !y$##PZ
--收缩数据和日志 '|gsmO
DBCC SHRINKDB Y*@7/2,
DBCC SHRINKFILE N?m)u,6-l
3、压缩数据库 9X*Z\-
dbcc shrinkdatabase(dbname) kL zjK]4 *
4、转移数据库给新用户以已存在用户权限 xp1/@Pw?
exec sp_change_users_login 'update_one','newname','oldname' te[uAJ1 N
go O^\:J2I(
5、检查备份集 <N<0 ?GQ
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' W!HjO;
6、修复数据库 q+[ )i6!?
ALTER DATABASE [dvbbs] SET SINGLE_USER .=YV
GO g5#LoGc
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK hYyIC:PXR
GO K3vZ42n
ALTER DATABASE [dvbbs] SET MULTI_USER (_#E17U)_
GO ~Q=;L>Qd
7、日志清除 p[&Jl
SET NOCOUNT ON s2L]H
DECLARE @LogicalFileName sysname, lO\HchGzB
@MaxMinutes INT, o.r D
@NewSize INT FrMXf,}
USE tablename -- 要操作的数据库名 h];H]15&
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 *-*V>ntvT$
@MaxMinutes = 10, -- Limit on time allowed to wrap log. e,#w*|
@NewSize = 1 -- 你想设定的日志文件的大小(M) )7Hx<?P
-- Setup / initialize nN$.^!;&
DECLARE @OriginalSize int N'{Yhx u
SELECT @OriginalSize = size VEa"^{,w
FROM sysfiles ;e_us!Sn
WHERE name = @LogicalFileName l'<&H#A;'
SELECT 'Original Size of ' + db_name() + ' LOG is ' + zATOFV
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + jhz*Y}MX
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' v1i-O'
FROM sysfiles F
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WHERE name = @LogicalFileName Ruq;:5u
CREATE TABLE DummyTrans 3KqRw (BK
(DummyColumn char (8000) not null) i9 CQ~
DECLARE @Counter INT, zdem}kBIe
@StartTime DATETIME, @G]*]rkKb
@TruncLog VARCHAR(255) m~;.kc
SELECT @StartTime = GETDATE(), U$DZht4>u
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' Wk^{Tn/]
DBCC SHRINKFILE (@LogicalFileName, @NewSize) {_W8Qm`.
EXEC (@TruncLog) 0X99D2c
-- Wrap the log if necessary. /Q9Cvj)"
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired _LgP
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) r[):'ys,C
AND (@OriginalSize * 8 /1024) > @NewSize =M:Po0?0E
BEGIN -- Outer loop. % dFz[b
SELECT @Counter = 0 a(IE8:yU`
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) uUS~"\`fk
BEGIN -- update %npLgCF
INSERT DummyTrans VALUES ('Fill Log') ({Yfsf,
DELETE DummyTrans OS%[SHs
SELECT @Counter = @Counter + 1 %gn@B2z
END Xqe Qj}2kA
EXEC (@TruncLog) cl#XiyK>
END @Wd(>*"zw
SELECT 'Final Size of ' + db_name() + ' LOG is ' + "<Di
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + C<C^7-5
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' z( ^?xv
FROM sysfiles 3Yx'/ =]
WHERE name = @LogicalFileName M'|[:I.V
DROP TABLE DummyTrans 5o{U$
SET NOCOUNT OFF 8|=
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8、说明:更改某个表 ~9@527m<',
exec sp_changeobjectowner 'tablename','dbo' ]?}pJ28
9、存储更改全部表 3
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CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch 2OI 0B\
@OldOwner as NVARCHAR(128), ekfa"X_
@NewOwner as NVARCHAR(128) D:K"J><@
AS 5mVO9Qj
DECLARE @Name as NVARCHAR(128) s hq
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DECLARE @Owner as NVARCHAR(128) AEf[:]i]
DECLARE @OwnerName as NVARCHAR(128) %d-WQwJ
DECLARE curObject CURSOR FOR |61ns6i!
select 'Name' = name, H{_D#It
'Owner' = user_name(uid) 6 ym$8^
from sysobjects ADxje%!1O
where user_name(uid)=@OldOwner -1$z=,q'
order by name (!m6>m2
OPEN curObject =>o !
FETCH NEXT FROM curObject INTO @Name, @Owner a`9pHH:7Q
WHILE(@@FETCH_STATUS=0) *E>R1bJ8
BEGIN s 7%iuP
if @Owner=@OldOwner V_^pPBa
begin IEM{?
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ]p4?nT@]
exec sp_changeobjectowner @OwnerName, @NewOwner qfAnMBM1@
end $AZ=;iP-
-- select @name,@NewOwner,@OldOwner ?&qQOM~b-\
FETCH NEXT FROM curObject INTO @Name, @Owner GM8>u O
END r.u\qPT&
close curObject j,%i.[8S
deallocate curObject U7fNA7#x"
GO li{<F{7
10、SQL SERVER中直接循环写入数据 '9qyf<MlY
declare @i int Vnb@5W2\
set @i=1 ut]&3f''
while @i<30 -=lL{oB1
begin 7On.y*
insert into test (userid) values(@i) lHliMBSc
set @i=@i+1 Bn.R,B0PL
end E@Ewx;P5
小记存储过程中经常用到的本周,本月,本年函数 !z:j-gT3
Dateadd(wk,datediff(wk,0,getdate()),-1) 0%|)=T3Slu
Dateadd(wk,datediff(wk,0,getdate()),6) V2;Nv\J\
Dateadd(mm,datediff(mm,0,getdate()),0) gDw(_KC
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) ,9F3~Ryt(
Dateadd(yy,datediff(yy,0,getdate()),0) 2t0VbAO1{
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) '%+LQ"Bp
上面的SQL代码只是一个时间段 8"LM:0x
Dateadd(wk,datediff(wk,0,getdate()),-1) qv2J0'd'.
Dateadd(wk,datediff(wk,0,getdate()),6) VWYNq^<AT
就是表示本周时间段. e<8KZ
下面的SQL的条件部分,就是查询时间段在本周范围内的: I@Yk &aU
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) GVf[H2%H
而在存储过程中 'm<L}d
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) z#n+iC$9
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) vy7?]}MvV