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。 L,@lp
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一、基础 IB7E}56l
1、说明:创建数据库 &JI8]JmU)
CREATE DATABASE database-name C73kJa
2、说明:删除数据库 z]9MM
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drop database dbname #
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3、说明:备份sql server !I
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--- 创建 备份数据的 device \K!VNB>h
USE master Z/;aT -N
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' Vy,DN~ag
--- 开始 备份 5o8EC"
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BACKUP DATABASE pubs TO testBack {,~3.5u
4、说明:创建新表 q%?in+l
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) cpJ|w3xB
根据已有的表创建新表: Hg$lXtn]
A:create table tab_new like tab_old (使用旧表创建新表) ~`:L?Jkb6H
B:create table tab_new as select col1,col2... from tab_old definition only 1PV'?tXp(
5、说明:删除新表 <yFu*(Q
drop table tabname :zF,A,)
6、说明:增加一个列 P(z++A&
Alter table tabname add column col type ~O&:C{9=
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。 <<R*2b
7、说明:添加主键: Alter table tabname add primary key(col) .UY^oR=b{
说明:删除主键: Alter table tabname drop primary key(col) ;x@~A^<el
8、说明:创建索引:create [unique] index idxname on tabname(col....) fDU!~/#
删除索引:drop index idxname wx0j(:B]
注:索引是不可更改的,想更改必须删除重新建。 ?oHpFlj
9、说明:创建视图:create view viewname as select statement 1Z~FCJz
删除视图:drop view viewname lv+TD!b
10、说明:几个简单的基本的sql语句 b7?hI
选择:select * from table1 where 范围 (c
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插入:insert into table1(field1,field2) values(value1,value2) 8C9-_Ng`
删除:delete from table1 where 范围 "u^H#L>-q
更新:update table1 set field1=value1 where 范围 P! #[mio
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! +s DV~\Vu
排序:select * from table1 order by field1,field2 [desc] T <ET
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总数:select count as totalcount from table1 &AbNWtCV+G
求和:select sum(field1) as sumvalue from table1 *.d)OOpLo
平均:select avg(field1) as avgvalue from table1 \ Et3|Iv
最大:select max(field1) as maxvalue from table1 (S\[Y9
最小:select min(field1) as minvalue from table1 U0N 60
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11、说明:几个高级查询运算词 FSW_<%
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A: UNION 运算符 [;),\\u,d
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。 PKg@[<g43
B: EXCEPT 运算符 ")XHak.JX
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。 &H/'rd0M
C: INTERSECT 运算符 GM f
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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。 A!WKnb_`
注:使用运算词的几个查询结果行必须是一致的。 z !rL
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12、说明:使用外连接 * kDC liL
A、left outer join: Cl8Cg~2
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。 fN^8{w/O
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 \B,@`dw
B:right outer join: P%&0]FCx
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。
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C:full outer join: c?[I?ytl
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。 My[pr_xg
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二、提升 c>:wd@w
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 9} M?P
法一:select * into b from a where 1<>1 ?:I* 8Fj
法二:select top 0 * into b from a hVAn>_(
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) NzOx0WLF
insert into b(a, b, c) select d,e,f from b; "2$fi{9
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) ryUQU^v
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 o5uph=Q{
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. peuZ&yK+"
4、说明:子查询(表名1:a 表名2:b) Ep3N&Imp
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) O$j7i:G'5
5、说明:显示文章、提交人和最后回复时间 '3DXPR^B6
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b F {4bo$~>
6、说明:外连接查询(表名1:a 表名2:b) ']z{{UNUN
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c xvl#w
7、说明:在线视图查询(表名1:a ) x'>9d
select * from (SELECT a,b,c FROM a) T where t.a > 1; 4`]^@"{
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 ]i ,{
select * from table1 where time between time1 and time2 D_^
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select a,b,c, from table1 where a not between 数值1 and 数值2 KD7dye
9、说明:in 的使用方法 Tg)|or/%
select * from table1 where a [not] in ('值1','值2','值4','值6') {|_M
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10、说明:两张关联表,删除主表中已经在副表中没有的信息
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delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) j<jN05p
11、说明:四表联查问题: })8N5C+KU
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... a PfO$b:
12、说明:日程安排提前五分钟提醒 suiS&$-E
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 A,hJIe
13、说明:一条sql 语句搞定数据库分页 cyv`B3}
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 Z=Y& B>:[
14、说明:前10条记录 6@ IXqKz
select top 10 * form table1 where 范围 BmMGx8P
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.) u9GQU
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) L<-_1!wh
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 FvXZ<(A{
(select a from tableA ) except (select a from tableB) except (select a from tableC) \[_t]'p
17、说明:随机取出10条数据 0s3%Kqi[
select top 10 * from tablename order by newid() g:D>.lKd
18、说明:随机选择记录 _w(7u(Z
select newid() R0]1xGz
19、说明:删除重复记录 (\hx` Yh=>
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) 7#ibN!
20、说明:列出数据库里所有的表名 q#ClnG*
select name from sysobjects where type='U' Ou!2[oe@M
21、说明:列出表里的所有的 X0H!/SlS
select name from syscolumns where id=object_id('TableName') xH(lm2kvT
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。 Qu"\wE^.`
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 NAQAU
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显示结果: #Z`q+@@]A
type vender pcs w?k>:,'[
电脑 A 1 i6tf2oqO7
电脑 A 1 ith
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光盘 B 2 Bp`]
光盘 A 2 A8fOQ
手机 B 3 ;F!5%}OcL%
手机 C 3 iWB=sL&p
23、说明:初始化表table1 wQH<gJE/:
TRUNCATE TABLE table1 (*nT(Adk
24、说明:选择从10到15的记录 [.'|_l
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc &(G\[RWp\
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三、技巧 ?{|q5n
1、1=1,1=2的使用,在SQL语句组合时用的较多 \y)rt )
"where 1=1" 是表示选择全部 "where 1=2"全部不选, { MSkHf=
如: |\<`Ib4j
if @strWhere !='' v/0QOp
begin j4qR(p(vC
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere }=UHbU.n~!
end }Jve cRtg1
else W*4-.*U8a
begin ox>^>wR*
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' .TMs bZ|j
end ^aMg/.j
我们可以直接写成 uK#4(eY=W
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere gA5/,wDO
2、收缩数据库 ] =xE
--重建索引 7he,?T)vD
DBCC REINDEX V!ZC(
DBCC INDEXDEFRAG $L>@Ed<
--收缩数据和日志 }Qc@m9;bH
DBCC SHRINKDB BNl5!X^{
DBCC SHRINKFILE c74.< @w
3、压缩数据库 6C^
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dbcc shrinkdatabase(dbname) m
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4、转移数据库给新用户以已存在用户权限 ^f
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exec sp_change_users_login 'update_one','newname','oldname' +EAsW(F1
go z^q0/'
5、检查备份集 VT%NO'0
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' /W30~y
6、修复数据库 :P\7iW
ALTER DATABASE [dvbbs] SET SINGLE_USER ;|5F[
GO wj<6kG
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK /y#f3r+*2
GO =Z3 F1Cq?
ALTER DATABASE [dvbbs] SET MULTI_USER fue(UMF~
GO Sh~dwxp*"
7、日志清除 }6}l7x
SET NOCOUNT ON r
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DECLARE @LogicalFileName sysname, )!Z*.?
@MaxMinutes INT, -M~:lK]n
@NewSize INT dulI&_x
USE tablename -- 要操作的数据库名 kr5">"7
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 VimE@ Hz
@MaxMinutes = 10, -- Limit on time allowed to wrap log. +I:Unp
@NewSize = 1 -- 你想设定的日志文件的大小(M) };bEU wGWf
-- Setup / initialize nQtWvT
DECLARE @OriginalSize int R'`qKc
SELECT @OriginalSize = size z'U1bMg
FROM sysfiles "f2$w
WHERE name = @LogicalFileName p* (JjH
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 9y8&9<#
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + S6M}WR^,
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' +nhLIO{{L
FROM sysfiles Mj?`j_X
WHERE name = @LogicalFileName 4qbBc1,7y
CREATE TABLE DummyTrans /P3 <"?#k
(DummyColumn char (8000) not null) \*y-g@-{W$
DECLARE @Counter INT, V-2(?auZd
@StartTime DATETIME, |t&>5HM
@TruncLog VARCHAR(255) _LUhZlw
SELECT @StartTime = GETDATE(), \0I_<
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' ,RI Gc US
DBCC SHRINKFILE (@LogicalFileName, @NewSize) Y>T-af49
EXEC (@TruncLog) 8f4b&ah
-- Wrap the log if necessary. 4Zddw0|2
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired LTCb@L{^i
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) #s(BuVU
AND (@OriginalSize * 8 /1024) > @NewSize T_
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BEGIN -- Outer loop. S9D<8j^
SELECT @Counter = 0 #PW9:_BE
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) #ut
BEGIN -- update Jk11fn;\>
INSERT DummyTrans VALUES ('Fill Log') .x.]`b(
DELETE DummyTrans rgv?gaQ>
SELECT @Counter = @Counter + 1 l
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END w"|L:8
EXEC (@TruncLog) 1..+F0U
END a=1@*ID
SELECT 'Final Size of ' + db_name() + ' LOG is ' + NC`aP0S
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + o]_dJB
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' vjCu4+w($Z
FROM sysfiles aQc leTb
WHERE name = @LogicalFileName ^4hO
DROP TABLE DummyTrans Xp% v.M
SET NOCOUNT OFF HTS0s\R$
8、说明:更改某个表 uc\Kg1{
exec sp_changeobjectowner 'tablename','dbo' 9c'xHO`
9、存储更改全部表 f:w?pE
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch CL;}IBd a
@OldOwner as NVARCHAR(128), ~.nmI&3
@NewOwner as NVARCHAR(128) ~2N"#b&J
AS J#(LlCs?@c
DECLARE @Name as NVARCHAR(128) D&
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DECLARE @Owner as NVARCHAR(128) }W8;=$jr
DECLARE @OwnerName as NVARCHAR(128) 4Uo&d#o)C-
DECLARE curObject CURSOR FOR 7`Ak)F:V
select 'Name' = name, \fdv]f
'Owner' = user_name(uid) `r':by0M
from sysobjects D|p9qe5%
where user_name(uid)=@OldOwner 9};8?mucr
order by name _,0
OPEN curObject FUb\e-Q=
FETCH NEXT FROM curObject INTO @Name, @Owner Y%^w:|f^
WHILE(@@FETCH_STATUS=0) !zpRrx_
BEGIN k FD;i
if @Owner=@OldOwner <w9JRpFY
begin XJ\DVZ
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ncdKj}
exec sp_changeobjectowner @OwnerName, @NewOwner (OL4Ex' ]
end iByf{ I>+
-- select @name,@NewOwner,@OldOwner pRpBhm;iJ
FETCH NEXT FROM curObject INTO @Name, @Owner m,w A:o$'
END hEH?[>9
close curObject s`8= 3]w
deallocate curObject #L;dI@7C
GO 9T9!kb
10、SQL SERVER中直接循环写入数据 5PJhEB
declare @i int Y=I'czg
set @i=1 =v&hWjP
while @i<30 >Q;l(fdj
begin n'LrQU
insert into test (userid) values(@i) Uz8ff
set @i=@i+1
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end 'KL0@l
小记存储过程中经常用到的本周,本月,本年函数 v$v-2y'%
Dateadd(wk,datediff(wk,0,getdate()),-1) -f^tE,-
Dateadd(wk,datediff(wk,0,getdate()),6) P4'Q/Sj
Dateadd(mm,datediff(mm,0,getdate()),0) I6av6t}
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) tw/dD +
Dateadd(yy,datediff(yy,0,getdate()),0) a#k6&3m&
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) P|E| $)m
上面的SQL代码只是一个时间段 6;d*r$0Fc
Dateadd(wk,datediff(wk,0,getdate()),-1) 1(R}tRR7 R
Dateadd(wk,datediff(wk,0,getdate()),6) ZvX*t)VjTz
就是表示本周时间段. *OsQ}onv
下面的SQL的条件部分,就是查询时间段在本周范围内的: _6hQ %hv8
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) i9|Sa6vuI
而在存储过程中 fU}ub2_in
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) |aS.a&vwR
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) @*XV`_!h