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。 D6=Z%h\*
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一、基础 ms@*JCL!t
1、说明:创建数据库 ^V#9{)B
CREATE DATABASE database-name X`JWYb4
2、说明:删除数据库 "7mYs)=
drop database dbname a|Io)Qhr
3、说明:备份sql server $hZb<Xz
--- 创建 备份数据的 device rJ|Q%utYz
USE master fl #gWAM
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' (Z;;v|F.i=
--- 开始 备份 <5X?6*Qvr
BACKUP DATABASE pubs TO testBack r9McCebIW
4、说明:创建新表 SAMP,un7
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ;jS2bc:8a
根据已有的表创建新表: FR&4i" +
A:create table tab_new like tab_old (使用旧表创建新表) Y_tLSOD#/
B:create table tab_new as select col1,col2... from tab_old definition only 3z';Zwz &X
5、说明:删除新表 +LuGjDn0
drop table tabname M0zJGIT~b
6、说明:增加一个列 ofH=h
Alter table tabname add column col type ^m8T$^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。 :iqFC >D
7、说明:添加主键: Alter table tabname add primary key(col) &7"a.&*9xX
说明:删除主键: Alter table tabname drop primary key(col) /T1zz2l~
8、说明:创建索引:create [unique] index idxname on tabname(col....) a+sHW<QeS
删除索引:drop index idxname
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注:索引是不可更改的,想更改必须删除重新建。 "uf*?m3
9、说明:创建视图:create view viewname as select statement D!<[\G
删除视图:drop view viewname [!H2i
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10、说明:几个简单的基本的sql语句 o=@0Bd8
选择:select * from table1 where 范围 d$Y3 a^O|
插入:insert into table1(field1,field2) values(value1,value2) t\Pn67t
删除:delete from table1 where 范围 ^PA >t$
更新:update table1 set field1=value1 where 范围 x(pq!+~K
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! |U)m'W-(q
排序:select * from table1 order by field1,field2 [desc] ilJeI@
总数:select count as totalcount from table1 =
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求和:select sum(field1) as sumvalue from table1 {5w'.Z]0v
平均:select avg(field1) as avgvalue from table1 HxCq6Y_m<
最大:select max(field1) as maxvalue from table1 G8b/eWtP
最小:select min(field1) as minvalue from table1 A[)od
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11、说明:几个高级查询运算词 V;0{o
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A: UNION 运算符 U
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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。 E`s9SE
B: EXCEPT 运算符 3jR,lEJyj
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。 GPlAQk
C: INTERSECT 运算符 :?W {vV
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。 OjO$.ecT
注:使用运算词的几个查询结果行必须是一致的。 hd{Vz{;W
12、说明:使用外连接 ?|!167/O
A、left outer join: ]AkHNgW
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。 ]4~-
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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 W _j`'WN/
B:right outer join: #vh1QV!Ho
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
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C:full outer join: Dlz||==
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。 :aHD'K
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二、提升 $Gt1T[:QUX
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) D>"U0*h
法一:select * into b from a where 1<>1 *I,3,zO
法二:select top 0 * into b from a `~|8eKFq!
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) pgT XyAP{
insert into b(a, b, c) select d,e,f from b; .
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3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) GtI]6t
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 j$r .&,m
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. u=^0n2ez
4、说明:子查询(表名1:a 表名2:b) ER,,K._?B
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) +W|MAJtg
5、说明:显示文章、提交人和最后回复时间 l*]9
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b /LMb~Hy,
6、说明:外连接查询(表名1:a 表名2:b) $T* ##kyE9
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 0=Jf93D5
7、说明:在线视图查询(表名1:a ) clfi)-^{K
select * from (SELECT a,b,c FROM a) T where t.a > 1; F jdh&9Zc
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 $__e7
select * from table1 where time between time1 and time2 &X0/7)*"v
select a,b,c, from table1 where a not between 数值1 and 数值2 nsR^TD;
9、说明:in 的使用方法 V"":_`1VW
select * from table1 where a [not] in ('值1','值2','值4','值6') bSH lR#!6
10、说明:两张关联表,删除主表中已经在副表中没有的信息 N_S>%Z+
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) LL3RC6;e
11、说明:四表联查问题: G#n99X@-
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... `L0aQ$'>z
12、说明:日程安排提前五分钟提醒 XP'Mv_!Z
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 <jdS0YT
13、说明:一条sql 语句搞定数据库分页 &We1i&w
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 u*_I7.}9
14、说明:前10条记录 UJ'
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select top 10 * form table1 where 范围 - bL
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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&E)S}wP
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) VU,\OOp
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 =w&%29BYq
(select a from tableA ) except (select a from tableB) except (select a from tableC) [{3WHS.
17、说明:随机取出10条数据 ,Yhy7w
select top 10 * from tablename order by newid() $$C5Q;7w!
18、说明:随机选择记录 o?A/
select newid() 5wXe^G
19、说明:删除重复记录 7kpCBLM(}
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) wqDRFZ1*P
20、说明:列出数据库里所有的表名 BcV;EEi
select name from sysobjects where type='U' TSu^.K
21、说明:列出表里的所有的 $$YLAgO4
select name from syscolumns where id=object_id('TableName') 4/D~H+k
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。 v8g3]MVj3
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 pJ7wd~wF*
显示结果: -eAo3
type vender pcs L^PZ\OC
电脑 A 1 q|m8G
电脑 A 1 PZ69aZ*Gs
光盘 B 2 t!^FWr&
光盘 A 2 3}O.B
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手机 B 3 g3{)AX[Uy
手机 C 3 e
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23、说明:初始化表table1 Wo5G23:xz
TRUNCATE TABLE table1 bu"Jb4_a>
24、说明:选择从10到15的记录 N]cGJU>$
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc =DTn9}u
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三、技巧 h`&@>uEiq
1、1=1,1=2的使用,在SQL语句组合时用的较多 =0xuH>WY}w
"where 1=1" 是表示选择全部 "where 1=2"全部不选, b!hxx Z
如: 9[5NnRv$P
if @strWhere !='' 2YK4SL
begin n`f},.NM|
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere {y0*cC
end :K{`0U&l5
else tF)K$!GR[
begin }|f\'S
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' (_]{[dFr%
end IBl}.o&]B#
我们可以直接写成 l/OG79qq
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere %kD WUJZ
2、收缩数据库 AF
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--重建索引 77/y{#Sk
DBCC REINDEX FM9b0qE
DBCC INDEXDEFRAG W#'c6Hq2c
--收缩数据和日志
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DBCC SHRINKDB MnFem $ @
DBCC SHRINKFILE b0LjNO@<
3、压缩数据库 FsZM_0>/s
dbcc shrinkdatabase(dbname) 4s*P5w_'/
4、转移数据库给新用户以已存在用户权限 Mr:*l`b_
exec sp_change_users_login 'update_one','newname','oldname' GN{\ccej
go )<4o"R:*
5、检查备份集 W"Dj+/uS
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' $V?zJ:a>L
6、修复数据库 T,(IdVlJ
ALTER DATABASE [dvbbs] SET SINGLE_USER M
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GO 3hR7 ./
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK Bt,qG1>$-
GO YU76(S9 0#
ALTER DATABASE [dvbbs] SET MULTI_USER BieII$\P%P
GO ,)V*xpp
7、日志清除 +`f gn9p
SET NOCOUNT ON .}ZX~k&P
DECLARE @LogicalFileName sysname, *Q=-7am
@MaxMinutes INT, aGp <%d
@NewSize INT Hk2@X(
USE tablename -- 要操作的数据库名 (o^V[zV
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 FVG|5'V^
@MaxMinutes = 10, -- Limit on time allowed to wrap log. 3leg,qd
@NewSize = 1 -- 你想设定的日志文件的大小(M) ^w2n
-- Setup / initialize &.kg8|s{
DECLARE @OriginalSize int t,N-|
SELECT @OriginalSize = size v)N6ZOj*C
FROM sysfiles i#lvt#2J0
WHERE name = @LogicalFileName m'k`p5[=h
SELECT 'Original Size of ' + db_name() + ' LOG is ' + UE7P =B
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + D]y6*Ha
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' }3:TPW5S
FROM sysfiles @babgP,
WHERE name = @LogicalFileName y5a^xRDw
CREATE TABLE DummyTrans EN.yU!N.4
(DummyColumn char (8000) not null) f]T1:N*t
DECLARE @Counter INT, g/+M&k$
@StartTime DATETIME, l@1f L%f
@TruncLog VARCHAR(255) hl}#bZ8]
SELECT @StartTime = GETDATE(), KtEMH
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' )2YU|
DBCC SHRINKFILE (@LogicalFileName, @NewSize) \Qk:\aLR
EXEC (@TruncLog) y(.WK8
-- Wrap the log if necessary. B>X+eK
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired 1sc #!^Oo
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 9ciL<'H\
AND (@OriginalSize * 8 /1024) > @NewSize TOMvJ>bF
BEGIN -- Outer loop. g/z9bOgIX
SELECT @Counter = 0 8f^URN<x
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) Kox~k?JK
BEGIN -- update yF0,}
INSERT DummyTrans VALUES ('Fill Log') Zpb3>0<R
DELETE DummyTrans m)_1->K
SELECT @Counter = @Counter + 1 /UyW&]nK
END [%l+
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EXEC (@TruncLog) EUuMSDp
END '4Z%{.;
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ^0{S!fs
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + m_rR e\
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' .e.vh:Sz
FROM sysfiles qx0o,oZN!
WHERE name = @LogicalFileName V<4)'UI?k9
DROP TABLE DummyTrans fbuop&FN+q
SET NOCOUNT OFF u6r-{[W}
8、说明:更改某个表 fY%Sw7ql<
exec sp_changeobjectowner 'tablename','dbo' mSQ!<1PM
9、存储更改全部表 yvDzxu
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch "r"]NyM
@OldOwner as NVARCHAR(128), T>f-b3dk
@NewOwner as NVARCHAR(128) qWE"vI22M
AS S"3g 1yU^_
DECLARE @Name as NVARCHAR(128) Z/-%Eb]L1
DECLARE @Owner as NVARCHAR(128) \
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DECLARE @OwnerName as NVARCHAR(128) vy|}\%*r~
DECLARE curObject CURSOR FOR Bl`e+&b
select 'Name' = name, 6w1:3~a
'Owner' = user_name(uid) #i2q}/w5`C
from sysobjects ixKQh};5/
where user_name(uid)=@OldOwner =:"@YD^a4
order by name gP1$#KgU
OPEN curObject svo^#V~h'
FETCH NEXT FROM curObject INTO @Name, @Owner BM&'3K_y
WHILE(@@FETCH_STATUS=0) Q ;k_q3
BEGIN v?LJ_>hw*T
if @Owner=@OldOwner =?*V3e3{
begin 3J,/bgL5
set @OwnerName = @OldOwner + '.' + rtrim(@Name) &OzJ^G\o
exec sp_changeobjectowner @OwnerName, @NewOwner M$&>"%Oi
end z%g<&Cq
-- select @name,@NewOwner,@OldOwner Ci*TX
FETCH NEXT FROM curObject INTO @Name, @Owner p$9N}}/c
END \17)=W
close curObject .{ x5(bi0S
deallocate curObject P{>T?-Hj
GO q"52-42
10、SQL SERVER中直接循环写入数据 ;=^WIC+Nr
declare @i int 0e7v ?UT
set @i=1 q0c)pxD%`
while @i<30 i;dr(c/ft
begin ,MvvW{EY
insert into test (userid) values(@i) MPL2#YU/a
set @i=@i+1 / TJTu_#
end \'p7,F{:>5
小记存储过程中经常用到的本周,本月,本年函数 W}=2?vHV=
Dateadd(wk,datediff(wk,0,getdate()),-1) ]iNSa{G
Dateadd(wk,datediff(wk,0,getdate()),6) v#/,,)m
Dateadd(mm,datediff(mm,0,getdate()),0) lJYv2EZ
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) \uPT-M*
Dateadd(yy,datediff(yy,0,getdate()),0) *@BBlkcx
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) (Q&z1XK3
上面的SQL代码只是一个时间段 /:USpuu
Dateadd(wk,datediff(wk,0,getdate()),-1) [FCNW0NV
Dateadd(wk,datediff(wk,0,getdate()),6) Bf*
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就是表示本周时间段. A23 Z)`
下面的SQL的条件部分,就是查询时间段在本周范围内的: )7`~U"r
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) EhVnt#`Si
而在存储过程中 WYzY#-j
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) e4`KnHsL
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) QB@*/Le