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。 8K;wX%_,
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一、基础 @8$3Q,fF(
1、说明:创建数据库 (e~vrSk+)~
CREATE DATABASE database-name o<f#Zi
2、说明:删除数据库 ~Bi{k'A9
drop database dbname Lu6?$N57rC
3、说明:备份sql server MF}}o0P
--- 创建 备份数据的 device #R#o/@|
USE master c9<&+
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' l0sBXs`3b
--- 开始 备份 ~=#jr0IZ
BACKUP DATABASE pubs TO testBack Qk_Mx"
4、说明:创建新表 |Ox!tvyr
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ~|!f6=
根据已有的表创建新表: mz<wYV*
A:create table tab_new like tab_old (使用旧表创建新表) giNyD4uO
B:create table tab_new as select col1,col2... from tab_old definition only i4p2]Nr
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5、说明:删除新表 M9J^;3Lrh
drop table tabname (F.vVldBy
6、说明:增加一个列 jaOt"iU.B
Alter table tabname add column col type 2{gd4Kt6.
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。 d$O)k+j
7、说明:添加主键: Alter table tabname add primary key(col) [-pB}1Dxb
说明:删除主键: Alter table tabname drop primary key(col) $At,D.mGkb
8、说明:创建索引:create [unique] index idxname on tabname(col....) }aJK^>^>A
删除索引:drop index idxname xdV $dDCT
注:索引是不可更改的,想更改必须删除重新建。 WER\04%D\m
9、说明:创建视图:create view viewname as select statement f[;l7
删除视图:drop view viewname ]di9dLT
10、说明:几个简单的基本的sql语句 \~{b;$N}
选择:select * from table1 where 范围 wRLj>nc
插入:insert into table1(field1,field2) values(value1,value2) Hrdz1:#6,
删除:delete from table1 where 范围 aN}l&4d
更新:update table1 set field1=value1 where 范围 zr1,A#BV
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! uV'w0`$y
排序:select * from table1 order by field1,field2 [desc] P-*=e8z{
总数:select count as totalcount from table1 Ou'<9m!9
求和:select sum(field1) as sumvalue from table1 9>1
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平均:select avg(field1) as avgvalue from table1 `tjH#W`
最大:select max(field1) as maxvalue from table1 DdG*eKC
最小:select min(field1) as minvalue from table1 ROfr
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11、说明:几个高级查询运算词 pSml+A:
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A: UNION 运算符 (9X>E+0E
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。 `;OEdeAM
B: EXCEPT 运算符 Wt8=j1>
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。 R/UL4R,)^
C: INTERSECT 运算符 oP 0ZJK&;
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。 Db5y";T
注:使用运算词的几个查询结果行必须是一致的。 *wY { ~zh
12、说明:使用外连接 nOE 1bf^l
A、left outer join: $sTvXf:g
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。 kl90w
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 5 Y|(i1
B:right outer join: ^^m3
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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。 k"V@9q;*
C:full outer join: HN j6Iw
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。 3|FZ!8D
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二、提升 >FRJvZ6
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) HcKZmL.wp
法一:select * into b from a where 1<>1 5csqu^/y
法二:select top 0 * into b from a 6'^Gh B
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) g\n0v~T+
insert into b(a, b, c) select d,e,f from b; B&Igm<72x
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) my|UlZ(qg
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 )U':NV2
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 1sHaG
4、说明:子查询(表名1:a 表名2:b) bR*/d-v^
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)
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5、说明:显示文章、提交人和最后回复时间 xqAXfJ.
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b ~1`ZPLVG
6、说明:外连接查询(表名1:a 表名2:b) e#uk+]
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c +l,6}tV9
7、说明:在线视图查询(表名1:a ) ?g5u#Q>!
select * from (SELECT a,b,c FROM a) T where t.a > 1; YV 5kzq
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 ZvS|a~jO
select * from table1 where time between time1 and time2 4XprVB
select a,b,c, from table1 where a not between 数值1 and 数值2 ?R;K`f9<
9、说明:in 的使用方法 5%5z@Ka
select * from table1 where a [not] in ('值1','值2','值4','值6') <X{hW^??)
10、说明:两张关联表,删除主表中已经在副表中没有的信息 f/VrenZ_
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) dLtn,qCX0^
11、说明:四表联查问题: YyZ>w2_MTi
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 ..... 3X,SCG
12、说明:日程安排提前五分钟提醒 =?, dX
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 \s[/{3
13、说明:一条sql 语句搞定数据库分页 ]DaC??%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 Y8fahQ#
14、说明:前10条记录 ZMVQo-=
select top 10 * form table1 where 范围 o@d+<6Um
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.) Zk4(
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) 3V"y|q
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 o5 fXe}pl@
(select a from tableA ) except (select a from tableB) except (select a from tableC) `iiZ
17、说明:随机取出10条数据 rLfhm
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select top 10 * from tablename order by newid() eZr}xo@9
18、说明:随机选择记录 l*yh(3~}
select newid() V(Dn!Nz
19、说明:删除重复记录 >;;tX3(
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) #n[1%8l,
20、说明:列出数据库里所有的表名 Yp_R+a^
select name from sysobjects where type='U' 9b0M'x'W5
21、说明:列出表里的所有的 P 3CzX48^
select name from syscolumns where id=object_id('TableName') $)5-}NJf'
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 (M5{y`Kk
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type !Hk$ t
显示结果: LcA~ a<_
type vender pcs (;11xu
电脑 A 1 9_6.%qj&
电脑 A 1 \G}$+
光盘 B 2 <Rl:=(]i~
光盘 A 2 V`n;W6Q17
手机 B 3 *FwHZZ~U
手机 C 3 LQnkpy3A
23、说明:初始化表table1 ^lP_{c
TRUNCATE TABLE table1 ?QnVWu2K
24、说明:选择从10到15的记录 SnhB$DG
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc B f_oIc
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三、技巧 u
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1、1=1,1=2的使用,在SQL语句组合时用的较多 ||lI_B
"where 1=1" 是表示选择全部 "where 1=2"全部不选, g]z[!&%Ahs
如: iZVMDJ?(Z]
if @strWhere !='' B~/LAD_
begin _V9 O,"DDc
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere Cyb-}l
end H8ws6}C
else vlD!YNy
begin 9 pGND]tIi
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' yvgn}F{}
end jQKlJi2xu
我们可以直接写成 \xH#X=J
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere e*Gm()Vu,
2、收缩数据库 b Hr2LhQCN
--重建索引 )m-l&UK
DBCC REINDEX *hHy>(*
DBCC INDEXDEFRAG 0RLyAC|
--收缩数据和日志 Rv)!p~V8
DBCC SHRINKDB 3q>6gaTv
DBCC SHRINKFILE "rj qDpH
3、压缩数据库 %r<c>sFJN
dbcc shrinkdatabase(dbname) Z(S=2r.
4、转移数据库给新用户以已存在用户权限 }+L!r53g6
exec sp_change_users_login 'update_one','newname','oldname' r~sx]=/
go m})q8b!S
5、检查备份集 a:oZ5PX=
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' Sv7_-#SW<(
6、修复数据库 QL>G-Rp
ALTER DATABASE [dvbbs] SET SINGLE_USER ;
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GO s7FJJTn
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK N
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GO _u`NIpXSP
ALTER DATABASE [dvbbs] SET MULTI_USER s_=/p5\
GO Ufz& 2
7、日志清除 LiyEF&_u
SET NOCOUNT ON h SZ0 }/
DECLARE @LogicalFileName sysname, S^GB\uJ
@MaxMinutes INT, 0x}8}
@NewSize INT FTy`#*7Ul
USE tablename -- 要操作的数据库名 x9#>0
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SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 +$#YW5wy
@MaxMinutes = 10, -- Limit on time allowed to wrap log. C*}TY)8
@NewSize = 1 -- 你想设定的日志文件的大小(M) NX$S^Z\QI
-- Setup / initialize ?I` BbT}
DECLARE @OriginalSize int i>9/vwe
SELECT @OriginalSize = size CjzfU*G
FROM sysfiles o|7]8K=
WHERE name = @LogicalFileName rAdYBr=0
SELECT 'Original Size of ' + db_name() + ' LOG is ' + B/i`
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + web=AQ5I4
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' jb' hqz
FROM sysfiles p%A(5DE
WHERE name = @LogicalFileName BX|+"AeF
CREATE TABLE DummyTrans "+REv_:
(DummyColumn char (8000) not null) d9XX^nY.
DECLARE @Counter INT, sW~Z?PFP
@StartTime DATETIME, `eIX*R
@TruncLog VARCHAR(255) `A.!<bO)]
SELECT @StartTime = GETDATE(), <}RU37,W
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 5#zwdoQ
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ~RVx~hh
EXEC (@TruncLog) J?XEF@?'G
-- Wrap the log if necessary. t6;Ln().Hw
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired `x"0
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) `0rEV_$
AND (@OriginalSize * 8 /1024) > @NewSize J}7iXTh
BEGIN -- Outer loop. 71+J{XOC
SELECT @Counter = 0 K?_4|
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) TxhTK5#f
BEGIN -- update ,w|f*L$
INSERT DummyTrans VALUES ('Fill Log') uc?QS~H&w
DELETE DummyTrans zh$[UdY6
SELECT @Counter = @Counter + 1 q/,W'lQ\;
END p6(n\eg R
EXEC (@TruncLog) % Ke:%##Y
END L&qzX)
SELECT 'Final Size of ' + db_name() + ' LOG is ' + DRD%pm(
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + R1z\b~@"
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' l1~>{:mq
FROM sysfiles Ox"4 y
WHERE name = @LogicalFileName YF=@nR$_~j
DROP TABLE DummyTrans k/vE|
SET NOCOUNT OFF ?op6_a-wm
8、说明:更改某个表 hq.z:D
exec sp_changeobjectowner 'tablename','dbo' E+$vIYq:W
9、存储更改全部表 x. r~e)x=
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch t;9f7~
@OldOwner as NVARCHAR(128), [8/E ;h
@NewOwner as NVARCHAR(128) 3LZ0EYVL
AS ^f{+p*i}:
DECLARE @Name as NVARCHAR(128) tvptawA.
DECLARE @Owner as NVARCHAR(128) }%EQ
DECLARE @OwnerName as NVARCHAR(128) 93%U;0w[Nw
DECLARE curObject CURSOR FOR M:OY8=V
select 'Name' = name, \xk`o5/{
'Owner' = user_name(uid) dL<okw
from sysobjects ,MwwA@,9-
where user_name(uid)=@OldOwner ZD1UMB0$4
order by name " *xQN "F
OPEN curObject /sENoQR
FETCH NEXT FROM curObject INTO @Name, @Owner I<*U^e
WHILE(@@FETCH_STATUS=0) 9rX[z :
BEGIN z3b8
if @Owner=@OldOwner od|w)?16
begin &yzC\XdA
set @OwnerName = @OldOwner + '.' + rtrim(@Name) EI2V<v
exec sp_changeobjectowner @OwnerName, @NewOwner t#kR@t+6$\
end $Q1:>i@I|g
-- select @name,@NewOwner,@OldOwner @B$ Y`eK\
FETCH NEXT FROM curObject INTO @Name, @Owner E7+y
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END 8vB~1tl;
close curObject pB{QO4qn
deallocate curObject z2og&|uT
GO h2+vl@X
10、SQL SERVER中直接循环写入数据 q>w@W:t Z
declare @i int #rzq9}9tB
set @i=1 tv)x(MX
while @i<30 v\:>}
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begin \$s<G|<P
insert into test (userid) values(@i) Py6c=&*
set @i=@i+1 Zi/l.=9n
end 0@1AH<
小记存储过程中经常用到的本周,本月,本年函数 o[^% 0uVF
Dateadd(wk,datediff(wk,0,getdate()),-1) 6}2vn5 E//
Dateadd(wk,datediff(wk,0,getdate()),6) ,U2
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Dateadd(mm,datediff(mm,0,getdate()),0) GiB3.%R`
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) gNl@T
Dateadd(yy,datediff(yy,0,getdate()),0) =PyU9C-@
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) ?3Wh.%n
上面的SQL代码只是一个时间段 ,T_HE3 K
Dateadd(wk,datediff(wk,0,getdate()),-1) =35^k-VS
Dateadd(wk,datediff(wk,0,getdate()),6) k( 1rp|qf
就是表示本周时间段. ="3Hc=1?R
下面的SQL的条件部分,就是查询时间段在本周范围内的: Z=DAA+T`
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) 2}1(j
而在存储过程中 c]F$$BT
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) r ,|T@|{
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) qev1bBW