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。 #Pulbk8
!ACWv*pW
@JWoF^U
一、基础 aNpeePF)z
1、说明:创建数据库 [*j
C
CREATE DATABASE database-name yuvt<kz
2、说明:删除数据库 ;u'mSJI'
drop database dbname tZ]|3wp
3、说明:备份sql server *JX)q
--- 创建 备份数据的 device QM1-w^
USE master |yi3y `f
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 9K@>{69WQ
--- 开始 备份 G"=tQ$ZU
BACKUP DATABASE pubs TO testBack N;A#3Ter
4、说明:创建新表 U/2g N
H
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) ]Ph~-O
根据已有的表创建新表: -}m#uUqI
A:create table tab_new like tab_old (使用旧表创建新表) Oph4&Ip[w
B:create table tab_new as select col1,col2... from tab_old definition only 6EhRCl
5、说明:删除新表 Ek +L"7
drop table tabname u,
%mVd
6、说明:增加一个列 X3DXEeBEL
Alter table tabname add column col type v2dCkn /
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 ?gb"S,
7、说明:添加主键: Alter table tabname add primary key(col) :>$)Snqo=n
说明:删除主键: Alter table tabname drop primary key(col) z^Nnt
8、说明:创建索引:create [unique] index idxname on tabname(col....) :5G3uN+\
删除索引:drop index idxname xQ62V11R6
注:索引是不可更改的,想更改必须删除重新建。 ^j?\_r'j
9、说明:创建视图:create view viewname as select statement L!3AiAnr
删除视图:drop view viewname q!k
F
10、说明:几个简单的基本的sql语句 AF1";duA
选择:select * from table1 where 范围 SzR0Mu3uK
插入:insert into table1(field1,field2) values(value1,value2) [IVT0
i
删除:delete from table1 where 范围 Sq&*K9:z
更新:update table1 set field1=value1 where 范围 H(ht{.sjI
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! )EYsqj
排序:select * from table1 order by field1,field2 [desc] (XJehdB0
总数:select count as totalcount from table1 I?v)>||Q
求和:select sum(field1) as sumvalue from table1 0Ng6Xg(QHc
平均:select avg(field1) as avgvalue from table1 Bo?uwi
最大:select max(field1) as maxvalue from table1 $jb 0/
最小:select min(field1) as minvalue from table1 N:!XtYA<
BJk:h-m [
Jp.Sow
jMUE&/k
11、说明:几个高级查询运算词 Wxg,y{(`
Eo\#*Cv*
.Lo$uKsW$l
A: UNION 运算符 I]>-~_
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。 a\\B88iRRZ
B: EXCEPT 运算符 4@|K^nT`
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。 -vI?b#
C: INTERSECT 运算符 $=$I^hV
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。 Z9ciS";L
注:使用运算词的几个查询结果行必须是一致的。 !%NxSJ
12、说明:使用外连接 PGMu6$
A、left outer join: g/so3F%v
.
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。 D5)qmu
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 9U6y<X
B:right outer join: ;h_"5/#
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。 mSAuS)YD
C:full outer join: TH/!z,(>
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。 &-+qB
>SK>
5oplV(<?*S
EuqmA7s8A
二、提升 ~)D2U:"^xm
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) C81+nR
法一:select * into b from a where 1<>1 E=w $r
法二:select top 0 * into b from a C/e`O|G
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) BD,JBu]
insert into b(a, b, c) select d,e,f from b; UuAn`oYhV
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) 3 S:}fPR
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 B4R!V!Z*
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. 'g#Ml`cm
4、说明:子查询(表名1:a 表名2:b) fyx-VXu
select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3) n.67f
5、说明:显示文章、提交人和最后回复时间 iwCnW7:
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b o(>!T=f
6、说明:外连接查询(表名1:a 表名2:b) [9a0J):w{
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c a@zKi;
7、说明:在线视图查询(表名1:a ) DTN @b!
select * from (SELECT a,b,c FROM a) T where t.a > 1; \P!v9LX(
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 a2UER1Yp"
select * from table1 where time between time1 and time2 TclZdk]%T
select a,b,c, from table1 where a not between 数值1 and 数值2 g8mVjM\B;
9、说明:in 的使用方法 wCeSs=[
select * from table1 where a [not] in ('值1','值2','值4','值6') >DQl&:-)t
10、说明:两张关联表,删除主表中已经在副表中没有的信息 7'j?GzaQ+
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) HGB96,o f9
11、说明:四表联查问题: 4XQ v
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... iBxCk^
12、说明:日程安排提前五分钟提醒 0F`@/C1y55
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 'Y6{89 y
13、说明:一条sql 语句搞定数据库分页 Kom$i<O?48
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 KwWqsuju
14、说明:前10条记录 TxwZA
select top 10 * form table1 where 范围 P f6rr9
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.) /J3e[?78u
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) X.,SXNS+B
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 (SoV2[|
(select a from tableA ) except (select a from tableB) except (select a from tableC) B[C2uVEX:
17、说明:随机取出10条数据 zrU0YHmt
select top 10 * from tablename order by newid() q+dY&4&u
18、说明:随机选择记录 H]"Z_n_
select newid() CBs0>M/
19、说明:删除重复记录 -n!.PsGO>
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) I
o7pp(
20、说明:列出数据库里所有的表名 9fvy)kX;s
select name from sysobjects where type='U' I5Foh|)
21、说明:列出表里的所有的 h(] O;a-
select name from syscolumns where id=object_id('TableName') d4[M{LSl
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。 J^pL_
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 >AV-i$4eQ@
显示结果: xv 's52x
type vender pcs %H~q3|z
电脑 A 1 =nA;,9%
电脑 A 1 SYB
}
e
光盘 B 2 %#02Z%?%
光盘 A 2 bU=!~W5
手机 B 3 WUGPi'x
手机 C 3 0fXdE ;M3
23、说明:初始化表table1 mR[J Xh9s
TRUNCATE TABLE table1 ?nB).fc
24、说明:选择从10到15的记录 DuZ51[3_L
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc m=PSCIb
joAR;J
wz9V)_V*
sJ7r9O`x
三、技巧 KKa"Ba$g
1、1=1,1=2的使用,在SQL语句组合时用的较多 Bca\grA
"where 1=1" 是表示选择全部 "where 1=2"全部不选, p{t2pfb
如: Sq UoXNw
if @strWhere !='' K`j#'`/KC
begin jbn{5af
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere #_QvnQ?I
end engql;
else {_ww1'|A
begin EHcqj;@m
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' ]$4 k+)6
end %K;,qS'N_
我们可以直接写成 aIRCz=N
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere * ?rw'
2、收缩数据库 b,~4O~z
--重建索引 ToCB*GlL
DBCC REINDEX wP6~HiC
DBCC INDEXDEFRAG $oH?oD1
--收缩数据和日志 bh6Mh<+
DBCC SHRINKDB g/mVd;#o
DBCC SHRINKFILE =JOupw
3、压缩数据库 q3VE\&*^F
dbcc shrinkdatabase(dbname) {w(6Tc
4、转移数据库给新用户以已存在用户权限 7cr+a4 T33
exec sp_change_users_login 'update_one','newname','oldname' `;*Wt9
go x7t<F4
5、检查备份集 @GBS-iT3
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' gr4Hh/V
6、修复数据库 4.|]R8Mn
ALTER DATABASE [dvbbs] SET SINGLE_USER yps7MM-r
GO [O&2!x
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ]3NH[&+
GO "|]'\4UdzQ
ALTER DATABASE [dvbbs] SET MULTI_USER u#\=g:
GO 2!-ZNd:(+
7、日志清除 LP7t*}PK
SET NOCOUNT ON 3:YZC9
DECLARE @LogicalFileName sysname, R8c1~'
@MaxMinutes INT, 8PDt 7
\
@NewSize INT 9&g//JlD
USE tablename -- 要操作的数据库名 p` B48TW
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 'vhgR2/
@MaxMinutes = 10, -- Limit on time allowed to wrap log. Ua,Lg.z
@NewSize = 1 -- 你想设定的日志文件的大小(M) ]B:g<}5$4
-- Setup / initialize p;"pTGoWi
DECLARE @OriginalSize int E&#AX:
SELECT @OriginalSize = size R4_4 FEo
FROM sysfiles w-AF5%gX
WHERE name = @LogicalFileName iPa!pg4m
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 8 %Lq~lk
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + Gz+Bk5#{
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' z(:0@ 5
FROM sysfiles zn_ InxR
WHERE name = @LogicalFileName %njX'7^u
CREATE TABLE DummyTrans y)"aQJ>
(DummyColumn char (8000) not null) Qa5<go{
DECLARE @Counter INT, F6}Pwz[c
@StartTime DATETIME, xA`Q4"[I
@TruncLog VARCHAR(255) (NFq/w%
SELECT @StartTime = GETDATE(), q<@f3[A
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 6U @3
xU`
DBCC SHRINKFILE (@LogicalFileName, @NewSize)
zKx?cEpE
EXEC (@TruncLog) kmi[u8iXD_
-- Wrap the log if necessary. (VO)
Q
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired w_ kHy_)
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) IwZn%>1N
AND (@OriginalSize * 8 /1024) > @NewSize {e/12q
BEGIN -- Outer loop. n (C*LK
SELECT @Counter = 0 GLcf'$l
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) .LIEZ^@
BEGIN -- update 0 oEw1!cY
INSERT DummyTrans VALUES ('Fill Log') Agl5[{]E
DELETE DummyTrans (WVN*OR?
SELECT @Counter = @Counter + 1 "
nq4!
END TF}<,aR
EXEC (@TruncLog) rG:IS=
END hWJ\dwF
SELECT 'Final Size of ' + db_name() + ' LOG is ' + z.
VuY3
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + H\Y.l,^
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' )p~\lM}?d
FROM sysfiles |<\o%89AM
WHERE name = @LogicalFileName 7Z0
)k9*
DROP TABLE DummyTrans ~Hd{+0
SET NOCOUNT OFF Ih ;6(5z
8、说明:更改某个表 `ihlKFX
exec sp_changeobjectowner 'tablename','dbo' u&I?LZ-=,
9、存储更改全部表 TKx.`Cf
m
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch U-QK
@OldOwner as NVARCHAR(128), O/e5LA
@NewOwner as NVARCHAR(128) L
Bb&av
AS Cl7IP<.
DECLARE @Name as NVARCHAR(128) 8+k\0fmy
DECLARE @Owner as NVARCHAR(128) !l?Go<^*L
DECLARE @OwnerName as NVARCHAR(128) (Q o
DECLARE curObject CURSOR FOR [D[s^<RJs
select 'Name' = name, h1z[ElEeoP
'Owner' = user_name(uid) >DBaKLu\
from sysobjects ]ctUl#j
where user_name(uid)=@OldOwner ]!d #2(
order by name S:v]3G
OPEN curObject >~){KV1~
FETCH NEXT FROM curObject INTO @Name, @Owner y"#o9"&>&
WHILE(@@FETCH_STATUS=0) >)R7*^m{'
BEGIN S)iv k x
if @Owner=@OldOwner D?44:'x+-
begin SpdQ<]
set @OwnerName = @OldOwner + '.' + rtrim(@Name) EFW'D=&h8
exec sp_changeobjectowner @OwnerName, @NewOwner %C" wUAY
end $ii/Q:w T"
-- select @name,@NewOwner,@OldOwner gGxgU$`#c
FETCH NEXT FROM curObject INTO @Name, @Owner @.yp IE\
END 'v GrbmK
close curObject !>TVDN>
deallocate curObject 4`o_r%
GO "o*(i7T=n
10、SQL SERVER中直接循环写入数据 *NS:X7p!V
declare @i int q{ItTvL
set @i=1 S;kI\;
while @i<30 O]DZb+O"
begin Zgkk%3'^'
insert into test (userid) values(@i) "EQ`Q=8
set @i=@i+1 cgNK67"(
end x~j>Lvw L
小记存储过程中经常用到的本周,本月,本年函数 s]#D;i8
Dateadd(wk,datediff(wk,0,getdate()),-1) /csj(8^w
Dateadd(wk,datediff(wk,0,getdate()),6) iBVV5 f
Dateadd(mm,datediff(mm,0,getdate()),0) -M2c8P:.b
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) <.HX_z3l
Dateadd(yy,datediff(yy,0,getdate()),0) Di5eD,N
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) dZFf/BXU
上面的SQL代码只是一个时间段 qZ'&zB)
Dateadd(wk,datediff(wk,0,getdate()),-1) #K.OJJaG
Dateadd(wk,datediff(wk,0,getdate()),6) 12U1DEd>-
就是表示本周时间段. 0k>bsn/j
下面的SQL的条件部分,就是查询时间段在本周范围内的: QFY1@2EC
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) F" FGPk
而在存储过程中 OBqaf
)W
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) a6wPkf7-H
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) sMlY!3{Ix