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。 WdT|xf.Q&
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一、基础 +@Y[i."^J
1、说明:创建数据库 +6=!ve}
CREATE DATABASE database-name I?K0bs+6
2、说明:删除数据库 cGp^;> ]M
drop database dbname 0
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3、说明:备份sql server ~K9U0ypH
--- 创建 备份数据的 device +[ItkfSod!
USE master nR7\ o(!
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' e0L;V@R
--- 开始 备份 ,:`6x[ +
BACKUP DATABASE pubs TO testBack 9)">()8
4、说明:创建新表 6fkr!&Dy7
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) Cu:Zn%
根据已有的表创建新表: U]|q4!WE
A:create table tab_new like tab_old (使用旧表创建新表) =r~.I
B:create table tab_new as select col1,col2... from tab_old definition only z m'jk D|
5、说明:删除新表 ! Cl/=0$[L
drop table tabname ju#63
6、说明:增加一个列 RVfe}4Stm#
Alter table tabname add column col type W%1S:2+Kl
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 }>0
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7、说明:添加主键: Alter table tabname add primary key(col) Db=gS=Qm
说明:删除主键: Alter table tabname drop primary key(col)
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8、说明:创建索引:create [unique] index idxname on tabname(col....) V5B-S.i@
删除索引:drop index idxname W(aRO
注:索引是不可更改的,想更改必须删除重新建。 -e~Uu
9、说明:创建视图:create view viewname as select statement @m V C
删除视图:drop view viewname qN@a<row&~
10、说明:几个简单的基本的sql语句 o!~bR
选择:select * from table1 where 范围 to3J@:V8e
插入:insert into table1(field1,field2) values(value1,value2) >| ?T|
删除:delete from table1 where 范围 [R4x[36Zp
更新:update table1 set field1=value1 where 范围 ;X(n3F
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! x1wxB
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排序:select * from table1 order by field1,field2 [desc] spJ(1F{|V
总数:select count as totalcount from table1 4*x!B![]y
求和:select sum(field1) as sumvalue from table1 PAHlj,n)
平均:select avg(field1) as avgvalue from table1 sh ;uKzQ
最大:select max(field1) as maxvalue from table1 3ZlI$r(
最小:select min(field1) as minvalue from table1 &>e DCs
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11、说明:几个高级查询运算词 `VtwKt*
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A: UNION 运算符 Ug21d42Z4
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。 $)Yo g]}
B: EXCEPT 运算符 :eW~nI.Vc
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 hli10p$
C: INTERSECT 运算符
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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。 bZ.N7X PH
注:使用运算词的几个查询结果行必须是一致的。 +ZKhmb!
12、说明:使用外连接 iwQ-(GjM[A
A、left outer join: cO,V8#H
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。 \'Ta8
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 Hc]1mM
B:right outer join: rf->mk{
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。 f_ztnRw
C:full outer join: #OWs3$9
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 A[kH_{to;
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二、提升 LUck>l\l
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) wy{>gvqK
法一:select * into b from a where 1<>1 Z=@)
法二:select top 0 * into b from a 6
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) d&uTiH? 0
insert into b(a, b, c) select d,e,f from b; m> (h_j
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) SDHc[66'
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 xGfDz*t
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 87KrSZ
4、说明:子查询(表名1:a 表名2:b) JGcD{RU|
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) YM`pNtQ
5、说明:显示文章、提交人和最后回复时间 q9Sz7_K
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b KC:4
6、说明:外连接查询(表名1:a 表名2:b) Reu{
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c *Ca)RgM
7、说明:在线视图查询(表名1:a ) JA(fam~{
select * from (SELECT a,b,c FROM a) T where t.a > 1; RX5.bVp
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8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 UZP6x2:=
select * from table1 where time between time1 and time2 _i[)$EgFm
select a,b,c, from table1 where a not between 数值1 and 数值2 2BDan^:-Av
9、说明:in 的使用方法 Wi[m`#
select * from table1 where a [not] in ('值1','值2','值4','值6') -I-Uh{)j
10、说明:两张关联表,删除主表中已经在副表中没有的信息 *3O >J"
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) MJ,ZXJXs
11、说明:四表联查问题: xs!g{~V{
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 ..... K3:|Tc(
12、说明:日程安排提前五分钟提醒 T_?nd T2
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 QZ3(u<f
13、说明:一条sql 语句搞定数据库分页 HDVl5X`j'
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 hNnX-^J<o
14、说明:前10条记录 pP* ~ =?
select top 10 * form table1 where 范围 rA1r#ksQ
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.) u=;nU(]M '
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) !?o$-+a|
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 VS|("**
(select a from tableA ) except (select a from tableB) except (select a from tableC) =HY1l}\
17、说明:随机取出10条数据 @f{_=~+
select top 10 * from tablename order by newid() 8ts+'65|F
18、说明:随机选择记录 vA"niO
select newid() \c~{o+UD-
19、说明:删除重复记录 [OZ=iz.
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) rN1U.FRe/
20、说明:列出数据库里所有的表名 -
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select name from sysobjects where type='U' HCG@#W<wc
21、说明:列出表里的所有的 B>Cs&}Y!
select name from syscolumns where id=object_id('TableName')
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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。 $tCcjBK\
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type { ^2W>^
显示结果: f{Fe+iPc
type vender pcs y168K[p
电脑 A 1 :X1cA3c!
电脑 A 1 t{SMSp
光盘 B 2 Y^6[[vaj2
光盘 A 2 T5Sg2a1&
手机 B 3 xN3 [Kp
手机 C 3 8b:clvh
23、说明:初始化表table1 &.Latx
TRUNCATE TABLE table1 bug Fl>
24、说明:选择从10到15的记录 AB"1(PbG
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc ZSPgci
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三、技巧 /*AJr
1、1=1,1=2的使用,在SQL语句组合时用的较多 -/UXd4S
"where 1=1" 是表示选择全部 "where 1=2"全部不选, R+E_#lP_$
如: DVl[t8K!
if @strWhere !='' hA*Z'.[
begin gf3U#L}P
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere V+O0k: o
end G7Z vfLR{:
else =0h|yjnL/
begin 0aC2 Pym^
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' Wk`bb!P_
end drENkS=,
我们可以直接写成 |,;twj[?4
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere b+IOh|
2、收缩数据库 i)7n c
--重建索引 ]Y4q'KH
DBCC REINDEX >X[|c"l.
DBCC INDEXDEFRAG =!(*5\IM
--收缩数据和日志 X_u@D;$
DBCC SHRINKDB ut4r~~Ar
DBCC SHRINKFILE v._Egk0
3、压缩数据库 )C>}"#J>
dbcc shrinkdatabase(dbname) ZU-4})7uSB
4、转移数据库给新用户以已存在用户权限 M!Z*QY."P
exec sp_change_users_login 'update_one','newname','oldname' hIVI\U,
go 3cOY0Z#T
5、检查备份集 dUoWo3r=
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' E+}GxFG-:
6、修复数据库 ;GE26Ymqly
ALTER DATABASE [dvbbs] SET SINGLE_USER &@YFje6Lcm
GO n .f4z<
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK AozmO
GO @sw9A93A
ALTER DATABASE [dvbbs] SET MULTI_USER Y^R?Q'
GO {gFAvMj#
7、日志清除 GS
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SET NOCOUNT ON $A;7Em
DECLARE @LogicalFileName sysname, C}b|2y
@MaxMinutes INT, =Kc|C~g
@NewSize INT )o#6-K+b
USE tablename -- 要操作的数据库名 ]<27Sw&yaG
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 17>5#JLP
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ]?0{(\
@NewSize = 1 -- 你想设定的日志文件的大小(M) E?Zb~xk
-- Setup / initialize +65oC x
DECLARE @OriginalSize int %cH8;5U40
SELECT @OriginalSize = size |XKOXa3.
FROM sysfiles nnt8 sf@\
WHERE name = @LogicalFileName 6FL?4>MZ
SELECT 'Original Size of ' + db_name() + ' LOG is ' + _urG_~q
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + J| SwQE~
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 6OL41g'
FROM sysfiles lSH ZV
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WHERE name = @LogicalFileName (U|)xA]y!
CREATE TABLE DummyTrans XC|*A$x,
(DummyColumn char (8000) not null) vv+TKO
DECLARE @Counter INT, F:M>z=
@StartTime DATETIME, 6xH;:B)d
@TruncLog VARCHAR(255) fyM3UA\U
SELECT @StartTime = GETDATE(), &Nc[$H7<
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' )@}A
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) }m6f^fs}
EXEC (@TruncLog) ,~(|p`
-- Wrap the log if necessary. QVIcb;&:}
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired lij B#1<8*
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) tNK^z7Dm
AND (@OriginalSize * 8 /1024) > @NewSize oW0gU?Rr)u
BEGIN -- Outer loop. Q |
SELECT @Counter = 0 ,{k<JA{
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) ~?#~ Ar
BEGIN -- update 8r,9OM
INSERT DummyTrans VALUES ('Fill Log') }>2t&+v+
DELETE DummyTrans gaQ[3g
SELECT @Counter = @Counter + 1 w{PUj
END N0+hejz
EXEC (@TruncLog) b-PSm=`
END B@-|b
SELECT 'Final Size of ' + db_name() + ' LOG is ' + hZcmP"wgC1
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + \B_i$<Sz
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' Le*`r2
FROM sysfiles 0|g[o:;fl_
WHERE name = @LogicalFileName NX?}{'f
DROP TABLE DummyTrans 5XDgs|8
SET NOCOUNT OFF 8tU>DJ}0
8、说明:更改某个表 mge#YV::
exec sp_changeobjectowner 'tablename','dbo' n_v02vFAHT
9、存储更改全部表 hM?`x(P
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch J*5hf: ?i
@OldOwner as NVARCHAR(128), 14mf}"z\
@NewOwner as NVARCHAR(128) >K\3*]>J3
AS o&~dGG4J
DECLARE @Name as NVARCHAR(128) '=VH6@vZ_'
DECLARE @Owner as NVARCHAR(128) >tN5vWW
DECLARE @OwnerName as NVARCHAR(128) wHf&R3fg
DECLARE curObject CURSOR FOR %NNj9Bl<VV
select 'Name' = name, DKX/W+#a
'Owner' = user_name(uid) W3)\co
from sysobjects 7%e1cI
where user_name(uid)=@OldOwner TN5>" ??"
order by name oz LH ]*
OPEN curObject +jUgx;u,
FETCH NEXT FROM curObject INTO @Name, @Owner ]D O&x+Rb
WHILE(@@FETCH_STATUS=0) e,(a6X
BEGIN Z:!IX^q;}n
if @Owner=@OldOwner Mm5c8[
begin 'xIyGDe
set @OwnerName = @OldOwner + '.' + rtrim(@Name) cS4DN
exec sp_changeobjectowner @OwnerName, @NewOwner x|8^i6xB
end !v0"$V5+i
-- select @name,@NewOwner,@OldOwner "# !D|[h0
FETCH NEXT FROM curObject INTO @Name, @Owner CphFv!k'Z
END (~JwLe@a
close curObject rvwa!YY}
deallocate curObject !$_~x
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GO ?\ZL#)hr"p
10、SQL SERVER中直接循环写入数据 yNBv-oe5
declare @i int %,0%NjK
set @i=1 OVZP x%a
while @i<30 K*1.'9/
begin 6ZcXS
insert into test (userid) values(@i) oe9lF*$/
set @i=@i+1 Hfh!l2P
end fN@{y+6
小记存储过程中经常用到的本周,本月,本年函数 [
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Dateadd(wk,datediff(wk,0,getdate()),-1) >%u@R3PH]
Dateadd(wk,datediff(wk,0,getdate()),6) AotCX7T2T
Dateadd(mm,datediff(mm,0,getdate()),0) 6#U^<`
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) /'ZKS T4
Dateadd(yy,datediff(yy,0,getdate()),0) l-<`m#/v
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) V7EQ4Om:It
上面的SQL代码只是一个时间段 TN\|fzj
Dateadd(wk,datediff(wk,0,getdate()),-1) R:M,tL-l
Dateadd(wk,datediff(wk,0,getdate()),6) ,beS0U]
就是表示本周时间段. yrnv!moc%t
下面的SQL的条件部分,就是查询时间段在本周范围内的: `rlk|&T1
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 0]B(a
而在存储过程中 8#w)X/
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 7b, (\Fm
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) &dr@6-xaq