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。 =%crSuP
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一、基础 =|3*Y0
1、说明:创建数据库 T$Rf
CREATE DATABASE database-name to] ~$~Q|>
2、说明:删除数据库 Ij7[2V]c
drop database dbname KA9v?_@{ F
3、说明:备份sql server D;oX*`
--- 创建 备份数据的 device 14 hE<u
USE master JHsxaX;c
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' zW ; sr.
--- 开始 备份 pJ@D}2u(
BACKUP DATABASE pubs TO testBack '!XVz$C
4、说明:创建新表 oMb@)7
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) kfs[*ku
根据已有的表创建新表: Uj)`(}r
A:create table tab_new like tab_old (使用旧表创建新表) zhC5%R &n/
B:create table tab_new as select col1,col2... from tab_old definition only SGLU7*sfd
5、说明:删除新表 ,D{D
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drop table tabname -j}zr yG-
6、说明:增加一个列 f;a55%3c
Alter table tabname add column col type Ob
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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。 /V E|F Ts
7、说明:添加主键: Alter table tabname add primary key(col) 89%#;C
说明:删除主键: Alter table tabname drop primary key(col) p y%RR*4#
8、说明:创建索引:create [unique] index idxname on tabname(col....) &jE@i#
删除索引:drop index idxname y-a3
注:索引是不可更改的,想更改必须删除重新建。 {bO
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9、说明:创建视图:create view viewname as select statement |Y;[)s =q
删除视图:drop view viewname >B+!fi'SS>
10、说明:几个简单的基本的sql语句 B5/"2i
选择:select * from table1 where 范围 %_ Vj'z~T
插入:insert into table1(field1,field2) values(value1,value2) 0-IL@Di`F
删除:delete from table1 where 范围 =a_ >")
更新:update table1 set field1=value1 where 范围 %2`.*]L
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料!
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排序:select * from table1 order by field1,field2 [desc] *~jTE;J
总数:select count as totalcount from table1 ,uCgC4EP
求和:select sum(field1) as sumvalue from table1 ;0:[X+"(
平均:select avg(field1) as avgvalue from table1 #HmZe98[%
最大:select max(field1) as maxvalue from table1 h9l 6AnbJ
最小:select min(field1) as minvalue from table1 [|APMMYK1
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11、说明:几个高级查询运算词 q3/ 0xN+?
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A: UNION 运算符 ,^&amWey
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|
B: EXCEPT 运算符 Ox&]{
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。 8QFg6#"O
C: INTERSECT 运算符 C "g bol^
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。 )cBO_
注:使用运算词的几个查询结果行必须是一致的。 lWk/vj<5
12、说明:使用外连接 'DtC=
A、left outer join: 9 kLA57
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%vl+qW
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 a3SBEkC
B:right outer join: wF$z ?L
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。 o%[swoM@
C:full outer join: Zd8`95
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。 }o@Dsx5
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二、提升 T8>aU
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) rE9Nt9}
法一:select * into b from a where 1<>1 S0!w]Ku
法二:select top 0 * into b from a }5lC8{wZ
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) p?'&P!
insert into b(a, b, c) select d,e,f from b; x5eSPF1
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) -$cO0RSY
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 5O"$'iL
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. w7QYWf'
4、说明:子查询(表名1:a 表名2:b) #7p!xf^
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) Z90]I<a~
5、说明:显示文章、提交人和最后回复时间 #,Cz+k*4
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b sTw+.m{F
6、说明:外连接查询(表名1:a 表名2:b) 9
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select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c :HkXsZ
7、说明:在线视图查询(表名1:a ) J)P7QTC
select * from (SELECT a,b,c FROM a) T where t.a > 1; QeG3X+
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 ,d$D0w
select * from table1 where time between time1 and time2 EfGy^`,'G
select a,b,c, from table1 where a not between 数值1 and 数值2 EM,=R
9、说明:in 的使用方法 ZP9x3MHe
select * from table1 where a [not] in ('值1','值2','值4','值6') +PKd
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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 7,5Bur
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) CRPE:7,D
11、说明:四表联查问题: <,,X\>B
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 ..... FPukV^
12、说明:日程安排提前五分钟提醒 F $1f8U8
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 EjP9/VG@=
13、说明:一条sql 语句搞定数据库分页 l9f%?<2D
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 xt1\Sie
14、说明:前10条记录 5Tq*]ZE
select top 10 * form table1 where 范围 PUErvLt
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) /-Z}=
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) e$o]f"(
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 arN=OB
(select a from tableA ) except (select a from tableB) except (select a from tableC) % !Ih=DZ
17、说明:随机取出10条数据 w[OUGn'
select top 10 * from tablename order by newid() W}@IUCRs
18、说明:随机选择记录 3>mAZZL5[
select newid() j?1wP6/NP
19、说明:删除重复记录 1x^Vv;K
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) LpN3cy>U
20、说明:列出数据库里所有的表名 ;Pe=cc"@
select name from sysobjects where type='U' 1C(sBU"
21、说明:列出表里的所有的 +P%k@w#<Z
select name from syscolumns where id=object_id('TableName') !TO+[g!
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。 z['2
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 D 3Tqk^5
显示结果: rG3?Z^&R+
type vender pcs )Bu#ln"
电脑 A 1 AejM\#>
电脑 A 1 y+nX(@~f]
光盘 B 2 "<&) G{
光盘 A 2 DcN!u6sJ
手机 B 3 ~]SCf@pRk
手机 C 3 DGNn#DP
23、说明:初始化表table1 P=R-1V
TRUNCATE TABLE table1 D.gD4g_O/
24、说明:选择从10到15的记录 !wTrWD!
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc zZ;V9KM>v
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三、技巧 B[9y<FB+
1、1=1,1=2的使用,在SQL语句组合时用的较多 5&qBG@Hw]
"where 1=1" 是表示选择全部 "where 1=2"全部不选, K%1`LT5:~
如: ehTv@2b
if @strWhere !='' D!&]jkUN
begin K
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set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere /h8100
end DMlr%)@{
else zxkO&DGRbN
begin Zxh<pd25Y
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' %F\.1\&eE
end 3Uej]}c
我们可以直接写成 _{$<s[S
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere zwk&3
2、收缩数据库 v[V7$.%5Q
--重建索引 v2k@yxt(
DBCC REINDEX [,(+r7aB
DBCC INDEXDEFRAG }m&\I
--收缩数据和日志 S_?sJwM
DBCC SHRINKDB wHh6y? g\
DBCC SHRINKFILE n'[>h0
3、压缩数据库 6sG5n7E-A
dbcc shrinkdatabase(dbname) qiH)J-
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4、转移数据库给新用户以已存在用户权限 J&&)%&h'I
exec sp_change_users_login 'update_one','newname','oldname' }42Hhu7j
go E;wT4 T=
5、检查备份集 RAWzQE}
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' i|m8#*Hd
6、修复数据库 \i+Ad@)
ALTER DATABASE [dvbbs] SET SINGLE_USER *Qyu
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GO &4ndi=.#rg
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK (I/iD.A
GO ]-_ ma
ALTER DATABASE [dvbbs] SET MULTI_USER #}l$<7ZU
GO _}F_Q5)
7、日志清除 }QBL{\E!
SET NOCOUNT ON _0UE*l$t
DECLARE @LogicalFileName sysname, =J|jCK[r
@MaxMinutes INT, BS(jC
@NewSize INT 0s79rJ
USE tablename -- 要操作的数据库名 &2S-scP
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 k(o(:-+x
@MaxMinutes = 10, -- Limit on time allowed to wrap log. Rh#`AM`)j
@NewSize = 1 -- 你想设定的日志文件的大小(M) S|af?IW
-- Setup / initialize ;hF}"shJN
DECLARE @OriginalSize int +s^nT{B@\
SELECT @OriginalSize = size a~?B/
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FROM sysfiles _]-8gr-T
WHERE name = @LogicalFileName R+z'6&/ =I
SELECT 'Original Size of ' + db_name() + ' LOG is ' + Kp^"<%RT
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 5h |aX
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' ix$
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FROM sysfiles >'4$g7o,
WHERE name = @LogicalFileName 'T$Cw\F&
CREATE TABLE DummyTrans T?RN} @D
(DummyColumn char (8000) not null) -xbs'[
DECLARE @Counter INT, rT\~VJ>+i
@StartTime DATETIME, 4>OS2b`.;
@TruncLog VARCHAR(255) /:ZwGyT;
SELECT @StartTime = GETDATE(), (:F]@vT
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' &xA>(|a\&-
DBCC SHRINKFILE (@LogicalFileName, @NewSize) vxOnv8(
EXEC (@TruncLog) (E7"GJ
-- Wrap the log if necessary. ]_|'N7J
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired EIfqRRTA
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ]#W7-Q;]
AND (@OriginalSize * 8 /1024) > @NewSize H4sW%nZ0
BEGIN -- Outer loop. m(o`;
SELECT @Counter = 0 { ^^5FE)%
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) #!E`%'
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BEGIN -- update nCQ".G
INSERT DummyTrans VALUES ('Fill Log') `\|tXl.
DELETE DummyTrans [oXSjLQm[
SELECT @Counter = @Counter + 1 |?ZU8I^vW
END ycSGv4
)
EXEC (@TruncLog) Ijap%l1I
END
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SELECT 'Final Size of ' + db_name() + ' LOG is ' + crOSr/I$
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + %@)R
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' T+aNX/c|>
FROM sysfiles !Z |_3
WHERE name = @LogicalFileName 4_ypFuS ^
DROP TABLE DummyTrans _>n)HG
SET NOCOUNT OFF yf!7
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8、说明:更改某个表 @$!6u0x
exec sp_changeobjectowner 'tablename','dbo' P3-O)m]jv
9、存储更改全部表 o.w/?
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch _|W&tB*
@OldOwner as NVARCHAR(128), ?i V}U
@NewOwner as NVARCHAR(128) m mZP;
AS 'wtb"0 }
DECLARE @Name as NVARCHAR(128) {&XTa`C
DECLARE @Owner as NVARCHAR(128) x;`Gn_
DECLARE @OwnerName as NVARCHAR(128) )+|wrK:*v
DECLARE curObject CURSOR FOR M$.bC0}T
select 'Name' = name, 60]VOQku
'Owner' = user_name(uid) YtKT3u:x
from sysobjects pUS: HJk|
where user_name(uid)=@OldOwner 4`mf^Kf
order by name uF1 4;
OPEN curObject UJQTArf
FETCH NEXT FROM curObject INTO @Name, @Owner I'^XEl?
WHILE(@@FETCH_STATUS=0) }st~$JsV1
BEGIN I\1"E y
if @Owner=@OldOwner 9C2pGfEbn}
begin M$Ui=GGq
set @OwnerName = @OldOwner + '.' + rtrim(@Name) "U"fsAc#
exec sp_changeobjectowner @OwnerName, @NewOwner 0^\H$An*k
end S.Kcb=;"L
-- select @name,@NewOwner,@OldOwner j,;f#+O`g
FETCH NEXT FROM curObject INTO @Name, @Owner SXYwhID=
END )/JVp>
close curObject 8t=O=l\
deallocate curObject maHz3:
GO
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10、SQL SERVER中直接循环写入数据 FyWf`XTO
declare @i int ("ix!\1K@
set @i=1 gK;dfrU.8Y
while @i<30 qoH:_o8ClO
begin kTfRm^
insert into test (userid) values(@i) X@}7 #Vt
set @i=@i+1 .a :7|L#a
end 1Az&BZU[
小记存储过程中经常用到的本周,本月,本年函数 qTRP2rH,L&
Dateadd(wk,datediff(wk,0,getdate()),-1) h.]^ o*DJ
Dateadd(wk,datediff(wk,0,getdate()),6) j>?nL~{
Dateadd(mm,datediff(mm,0,getdate()),0) u{&=$[;
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) lK7:qo
Dateadd(yy,datediff(yy,0,getdate()),0) 0tL5t7/Gr
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 1%vE 7a>{
上面的SQL代码只是一个时间段 Sz<:WY/(x
Dateadd(wk,datediff(wk,0,getdate()),-1) Gey-8
Dateadd(wk,datediff(wk,0,getdate()),6) p/Q< VV
就是表示本周时间段. V"(5U(v{~
下面的SQL的条件部分,就是查询时间段在本周范围内的: ,r~^<m
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) l3BN,HNv+
而在存储过程中 l3u+fE,;_
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) 568M4xzi
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) xzA!,75@U