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。 /"g[Ay
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一、基础 n^3NA|A
1、说明:创建数据库 |
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CREATE DATABASE database-name $a)JCErN
2、说明:删除数据库 hG< a
drop database dbname :K!GR
3、说明:备份sql server (0Zrfu^
--- 创建 备份数据的 device `,hW;p>-
USE master 5 >0\e_V
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' 0]/,m4a#n
--- 开始 备份 5?S{W
BACKUP DATABASE pubs TO testBack :4Id7Ce
4、说明:创建新表 []sB^UT
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) s,{RP0|
根据已有的表创建新表: Y8{T.\%\+
A:create table tab_new like tab_old (使用旧表创建新表) >}xAg7\^
B:create table tab_new as select col1,col2... from tab_old definition only w50.gr7
5、说明:删除新表 OYQXi
drop table tabname ?*(r1grHl
6、说明:增加一个列 ptnMCF
Alter table tabname add column col type sj?`7kg
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 A8CIP:Z
7、说明:添加主键: Alter table tabname add primary key(col) >;T$#LZ
说明:删除主键: Alter table tabname drop primary key(col) "P>$=X~Zi
8、说明:创建索引:create [unique] index idxname on tabname(col....) ym-lT|>Z
删除索引:drop index idxname
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注:索引是不可更改的,想更改必须删除重新建。 ,k`YDy|#e
9、说明:创建视图:create view viewname as select statement m? ]zomP
删除视图:drop view viewname Ncs4<"{$
10、说明:几个简单的基本的sql语句 ?HEo9/ *7
选择:select * from table1 where 范围 '2Mjz6mBDA
插入:insert into table1(field1,field2) values(value1,value2) #3 }5cC8_
删除:delete from table1 where 范围 ir( -$*J
更新:update table1 set field1=value1 where 范围 "^e}C@
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! 1"~O"m sb
排序:select * from table1 order by field1,field2 [desc] 6&/ Ew4 e
总数:select count as totalcount from table1 QSl:=Q'
求和:select sum(field1) as sumvalue from table1 _>Pe]3
平均:select avg(field1) as avgvalue from table1 c,{&
最大:select max(field1) as maxvalue from table1 sM);gI14
最小:select min(field1) as minvalue from table1 +aXMH T"U
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11、说明:几个高级查询运算词 wh7i
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A: UNION 运算符 6KZ8 .m}:
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 hSLwiX~
B: EXCEPT 运算符 P?yOLG+)l)
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 WsK"^"Z
C: INTERSECT 运算符 @[[Cs*-
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 |zRoXO`]-*
注:使用运算词的几个查询结果行必须是一致的。 h>mBkJ
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12、说明:使用外连接 7><*
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A、left outer join: R?={{+O
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 5KA
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SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c hr$VVbOho
B:right outer join: ;c \zgs~"T
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。 D!OG307P
C:full outer join: +lk\oj$S+
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 H *z0xxa
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二、提升 ,_TH@0{
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) s$+: F$Y0
法一:select * into b from a where 1<>1 NL>[8#
法二:select top 0 * into b from a lN=m$ J
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ~8n~4
insert into b(a, b, c) select d,e,f from b; eaZ)1od
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) ]
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insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 -h^} jP8
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. =4w^)'/
4、说明:子查询(表名1:a 表名2:b) CoKj'jA
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) B[U.CAUn
5、说明:显示文章、提交人和最后回复时间 ?
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select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b :g]HB,78
6、说明:外连接查询(表名1:a 表名2:b) }fa%JN %E
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c n79DS(t
7、说明:在线视图查询(表名1:a ) g)zn.]
select * from (SELECT a,b,c FROM a) T where t.a > 1; eA~_)-Z-
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 eiNk]KXAYX
select * from table1 where time between time1 and time2 $' I$n
select a,b,c, from table1 where a not between 数值1 and 数值2 41fm}
9、说明:in 的使用方法 (VF4FC
select * from table1 where a [not] in ('值1','值2','值4','值6') V~gUMu4ot
10、说明:两张关联表,删除主表中已经在副表中没有的信息 ZF11v(n
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) #k|g9`
11、说明:四表联查问题: }IalgQ(i
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 ..... Q e2/4j4
12、说明:日程安排提前五分钟提醒 *t]&b ;=gE
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 "8j;k5<
13、说明:一条sql 语句搞定数据库分页
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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 p;QX"2
14、说明:前10条记录 b\e)PUm#u@
select top 10 * form table1 where 范围 `'WY'\|C
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.) l2KxZteXY0
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) Al-%j- j@-
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 *{p&Fy55
(select a from tableA ) except (select a from tableB) except (select a from tableC) 'zD;:wT
17、说明:随机取出10条数据 w|UKMbRMU]
select top 10 * from tablename order by newid() Kt&$Si
18、说明:随机选择记录 0Ts_"p
select newid() FO3eg"{N
19、说明:删除重复记录 BBuYO$p
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ~sU!
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20、说明:列出数据库里所有的表名 ]mLTF',5
select name from sysobjects where type='U' ePcI^}{
21、说明:列出表里的所有的 }FdcbNsP
select name from syscolumns where id=object_id('TableName') Xta>
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。 eMPQ|
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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 sR0e&Y
显示结果: qKb-aP-
type vender pcs /j5-
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电脑 A 1 gm%bxr@X~
电脑 A 1 Y_ ;i
光盘 B 2 x#}eC'Q
光盘 A 2 1 0Tg> H
手机 B 3 Gv2./<{#
手机 C 3 PTc\I
23、说明:初始化表table1 G<WDyoN=O
TRUNCATE TABLE table1 @W5hrei
24、说明:选择从10到15的记录 a^)4q\E
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc :tS>D5dz(
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三、技巧 ~9>[ U%D
1、1=1,1=2的使用,在SQL语句组合时用的较多 CFrHNU
"where 1=1" 是表示选择全部 "where 1=2"全部不选, =K<I)2
如: uB%^2{uU
if @strWhere !='' c+K=pp@
begin uJ5%JB("E
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere UFY~D"%/
end ZK_@.O+ ]
else ~esEql=Q3'
begin aD3F!Sn
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' v]Q_
end (,9cCnvmYU
我们可以直接写成 r D!.N
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere |>fS"u
2、收缩数据库 1?#p !;&
--重建索引 z?> y
DBCC REINDEX 5Yibv6:3a
DBCC INDEXDEFRAG KJ{F,fr+v
--收缩数据和日志 4JQ`&:?r
DBCC SHRINKDB [q{Txe
DBCC SHRINKFILE 3 BhA.o
3、压缩数据库 L-:L=
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dbcc shrinkdatabase(dbname)
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4、转移数据库给新用户以已存在用户权限 TOF62,
exec sp_change_users_login 'update_one','newname','oldname' 3V!&y/c<
go D$!p+Q
5、检查备份集 d`][1rZk
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' &Or=_5Y`
6、修复数据库
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ALTER DATABASE [dvbbs] SET SINGLE_USER U.sPFt
GO T9v#Jb6
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK !U~#H_
GO j I@$h_n
ALTER DATABASE [dvbbs] SET MULTI_USER ?RAR
GO
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7、日志清除 8q[WfD
SET NOCOUNT ON >(4S `}K
DECLARE @LogicalFileName sysname, r@ *A
@MaxMinutes INT, 92ww[+RQ@
@NewSize INT 1?$!y
USE tablename -- 要操作的数据库名 7tO$'q*h
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 nVA'O
@MaxMinutes = 10, -- Limit on time allowed to wrap log. |}y}o:(
@NewSize = 1 -- 你想设定的日志文件的大小(M) Nc Mq>n
-- Setup / initialize ,
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DECLARE @OriginalSize int IMw)X0z
SELECT @OriginalSize = size Gqb-3ngH
FROM sysfiles q@Yt`$VTN
WHERE name = @LogicalFileName tZ24}~da
SELECT 'Original Size of ' + db_name() + ' LOG is ' + GoA>sK
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + T@.m^|~
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' t>u9NZt G
FROM sysfiles z"C(#Y56 x
WHERE name = @LogicalFileName ij5=f0^4.
CREATE TABLE DummyTrans DH*|>m&
(DummyColumn char (8000) not null) ew ,ed U
DECLARE @Counter INT, mqc Z3lsv
@StartTime DATETIME, g;Q^_4@
@TruncLog VARCHAR(255)
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SELECT @StartTime = GETDATE(), NGZ>:
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' T.N7`
DBCC SHRINKFILE (@LogicalFileName, @NewSize) 1gK3=Ys
EXEC (@TruncLog) L"<Eov6
-- Wrap the log if necessary. A;HKR4p;8
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired h#;K9#x6
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) i4Cb&h^
AND (@OriginalSize * 8 /1024) > @NewSize _rh.z_a7w
BEGIN -- Outer loop. BCB/cBE
SELECT @Counter = 0 <a}|G1 h
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) zd]L9 _
BEGIN -- update ghR]$SG
INSERT DummyTrans VALUES ('Fill Log') fB}5,22
DELETE DummyTrans 'ZgW~G]S
SELECT @Counter = @Counter + 1 ;//qjo
END )L("t
EXEC (@TruncLog) HCy} '}d
END 3;gtuqwD$
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ~}ZX^l&k{P
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + /s_$CSiB
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' Ybg`Z
FROM sysfiles =+\oL!^
WHERE name = @LogicalFileName 6_><W"r:]
DROP TABLE DummyTrans (pNng"/
SET NOCOUNT OFF V]cY+4Y
8、说明:更改某个表 7B :aJfxM
exec sp_changeobjectowner 'tablename','dbo' :m)?+
9、存储更改全部表 yKhzymS}T
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch
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@OldOwner as NVARCHAR(128), X*):N]
@NewOwner as NVARCHAR(128) }#^F'%zf
AS {XW>:EU'N
DECLARE @Name as NVARCHAR(128) )fr\V."
DECLARE @Owner as NVARCHAR(128) +JVfnTd
DECLARE @OwnerName as NVARCHAR(128) @C)h;TR
DECLARE curObject CURSOR FOR GQNiBsV
select 'Name' = name, P6'I:/V
'Owner' = user_name(uid) [=!MS?-G
from sysobjects Ik)Q0_<a
where user_name(uid)=@OldOwner "&|2IA
order by name ] 6B!eB
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OPEN curObject l0_O<
FETCH NEXT FROM curObject INTO @Name, @Owner ]gk1h=Y~h
WHILE(@@FETCH_STATUS=0) =Bx~'RYl1d
BEGIN !g:UM R
if @Owner=@OldOwner . r"?w
begin 9>P(eN
set @OwnerName = @OldOwner + '.' + rtrim(@Name) [!
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exec sp_changeobjectowner @OwnerName, @NewOwner IGQ8-#=
end 0~+k
-- select @name,@NewOwner,@OldOwner ((q(Q9(F
FETCH NEXT FROM curObject INTO @Name, @Owner je%12DM
END =?aB@&
close curObject __npX_4%S
deallocate curObject #O
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GO aoX$,~oI5
10、SQL SERVER中直接循环写入数据 4!|ar?Zy
declare @i int @SXgaWr
set @i=1 gH.^NO5\'
while @i<30 rP_)*)
begin 2G;d2LR:
insert into test (userid) values(@i) |&Wo-;Ud
set @i=@i+1 y9<Fv|Ric
end rJwJ5U
小记存储过程中经常用到的本周,本月,本年函数 )YnN9"8
Dateadd(wk,datediff(wk,0,getdate()),-1) mYX) =B{
Dateadd(wk,datediff(wk,0,getdate()),6) $Yc9><i
Dateadd(mm,datediff(mm,0,getdate()),0) ^f]pK&MAmN
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) WLb7]rCTp
Dateadd(yy,datediff(yy,0,getdate()),0) | w -W=v
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) H0 t1& :
上面的SQL代码只是一个时间段 OwUbm0)h^V
Dateadd(wk,datediff(wk,0,getdate()),-1) EG6fC4rfC
Dateadd(wk,datediff(wk,0,getdate()),6) IgJC>;]u
就是表示本周时间段. %4J?xhd
下面的SQL的条件部分,就是查询时间段在本周范围内的: UPF=X)!M
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) O:)@J b2
而在存储过程中 _aYQ(FO
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) !vw0Y,F&
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) {\I\4P