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。 W2CCLq1(
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一、基础 *h=|KOS
1、说明:创建数据库 Ok7i^-85
CREATE DATABASE database-name >EQd;Af
2、说明:删除数据库 U#=Q`
drop database dbname W0vdU;?%
3、说明:备份sql server eGZ{%\PH<
--- 创建 备份数据的 device vA(V.s`
USE master x.Sq2rw]V
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' YQU#aOl
--- 开始 备份 jD@KG
BACKUP DATABASE pubs TO testBack
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4、说明:创建新表 J(CqT/Au-
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) lM1Y }
根据已有的表创建新表: Jh3(5d"MV
A:create table tab_new like tab_old (使用旧表创建新表) !<psK[
B:create table tab_new as select col1,col2... from tab_old definition only -p|@En n
5、说明:删除新表 m791w8Vr
drop table tabname Zj )Bd*a
6、说明:增加一个列 =d#3& R]p
Alter table tabname add column col type q$[x*!~
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。 JJL#Y
7、说明:添加主键: Alter table tabname add primary key(col) 0E9LZOw4T
说明:删除主键: Alter table tabname drop primary key(col) tx=~bm"*?
8、说明:创建索引:create [unique] index idxname on tabname(col....) dpHK~n j\_
删除索引:drop index idxname $_N<! h*\
注:索引是不可更改的,想更改必须删除重新建。 %M+ID['K9/
9、说明:创建视图:create view viewname as select statement MjIp~?*
删除视图:drop view viewname <^}{sdOyu
10、说明:几个简单的基本的sql语句 16q"A$
选择:select * from table1 where 范围 6 /T_+K.k
插入:insert into table1(field1,field2) values(value1,value2) S^}@X?v
删除:delete from table1 where 范围 mz\d>0F U.
更新:update table1 set field1=value1 where 范围 cwK6$Ax
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! h(aF>a\Z
排序:select * from table1 order by field1,field2 [desc] Q_<CG[,6D1
总数:select count as totalcount from table1 vas
求和:select sum(field1) as sumvalue from table1 we6']iaV
平均:select avg(field1) as avgvalue from table1 $i@~$m7d-
最大:select max(field1) as maxvalue from table1 `&2AN%Xz
最小:select min(field1) as minvalue from table1 rYI9?q
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11、说明:几个高级查询运算词 +R}(t{b#
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A: UNION 运算符 8NLTq|sW
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。 Pyc/6~?
B: EXCEPT 运算符 ZRYs7 4<
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。 g`)2I+L7
C: INTERSECT 运算符 *Q bPz4,"
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。 CrHH Ob
注:使用运算词的几个查询结果行必须是一致的。 $N[-ks2{@
12、说明:使用外连接 S5R Q
A、left outer join: ,}%+5yH
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 |ToCRM
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c "7_6iB&@<
B:right outer join: Q>s> @hw
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 8E`rs)A
C:full outer join: %H\i}}PTe
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 Yv!%Is
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二、提升 /I~iUND"G
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 9kj71Jp&}
法一:select * into b from a where 1<>1 [4,=%ez
法二:select top 0 * into b from a 7B
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2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) ]Auk5M +
insert into b(a, b, c) select d,e,f from b; aNgaV$|2a
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) F)4Y;;#
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 F0
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例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. b!VaEK
4、说明:子查询(表名1:a 表名2:b) =\7o@ 38
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) TqK`X#Zq
5、说明:显示文章、提交人和最后回复时间 !K;\{/8
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b QjMH1S
6、说明:外连接查询(表名1:a 表名2:b) gE^
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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 \4y7!
7、说明:在线视图查询(表名1:a ) M{$EJS\d=
select * from (SELECT a,b,c FROM a) T where t.a > 1; U1<EAGo|
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 7r#U^d(
select * from table1 where time between time1 and time2 f]H[uzsV
select a,b,c, from table1 where a not between 数值1 and 数值2 bY:A7.p7#
9、说明:in 的使用方法 nff&~lwhZ
select * from table1 where a [not] in ('值1','值2','值4','值6') 6jFc'
10、说明:两张关联表,删除主表中已经在副表中没有的信息 \vbU| a
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) YX38*Ml+V
11、说明:四表联查问题: a[iuE`
select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... o|lEF+
12、说明:日程安排提前五分钟提醒 -d?9Acd
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 wS"[m>.{v
13、说明:一条sql 语句搞定数据库分页 +$M%"=tk
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 6tXx--Nh
14、说明:前10条记录 ]fz0E:x
select top 10 * form table1 where 范围 iD=VNf
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.) i8A{DMc,U
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) t b5k|
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 1qXqQA
(select a from tableA ) except (select a from tableB) except (select a from tableC) rjfcZ@
17、说明:随机取出10条数据 Oz{.>Pjn^o
select top 10 * from tablename order by newid() a=bP
18、说明:随机选择记录 c RBdIDIc
select newid() '6Dt@^-PZ
19、说明:删除重复记录 uKF?UXc
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) ^LgaMmz
20、说明:列出数据库里所有的表名 W,~s0a!
select name from sysobjects where type='U' p?S:J`q
21、说明:列出表里的所有的 p@`rBzGp
select name from syscolumns where id=object_id('TableName') yNVuSj
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。 S'~Zlv3`
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 ~qe9U 0
显示结果: jT/SZ|S
type vender pcs *oLAO/)n
电脑 A 1
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电脑 A 1 FtbqZN[
光盘 B 2 N\XZ=t^h(
光盘 A 2 V
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手机 B 3 |/K+tH
手机 C 3 PGZ .\i
23、说明:初始化表table1 V*P3C5l
TRUNCATE TABLE table1 G!},jO*"
24、说明:选择从10到15的记录 o3*IfD
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc &Npv~Iy
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三、技巧 seWYY $$
1、1=1,1=2的使用,在SQL语句组合时用的较多 [OFg
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"where 1=1" 是表示选择全部 "where 1=2"全部不选, 41 sClC"
如: !Irmc*;QE
if @strWhere !='' .m_yx{FZ=
begin is&A_C7yg
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere z#*M}RR
end Rfh#JO@%[
else _urv
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begin xzF@v>2S+
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' )2T?Z)"hO
end rQT@:$)
我们可以直接写成 s>`$]6wPa
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 9u<4Q_I`
2、收缩数据库 !FOPFPn
--重建索引 xXQ#?::m
DBCC REINDEX oj*5m+:>a
DBCC INDEXDEFRAG wWm1G)
--收缩数据和日志 S N_!o2F2
DBCC SHRINKDB v
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DBCC SHRINKFILE +T:F :X`
3、压缩数据库 3DRbCKNL
dbcc shrinkdatabase(dbname) B6~a `~"
4、转移数据库给新用户以已存在用户权限 -E~pCN(E
exec sp_change_users_login 'update_one','newname','oldname' _U)BOE0o
go %.,-dV'
5、检查备份集 shjbb
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' z VleJ!d
6、修复数据库 prE~GO7Z
ALTER DATABASE [dvbbs] SET SINGLE_USER g[fCvWm#d
GO +^$FA4<~
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK 5|YpkY
GO ?2hoY
ALTER DATABASE [dvbbs] SET MULTI_USER [/uqH
GO I$sJ8\|gw'
7、日志清除 9ui_/[K
SET NOCOUNT ON }.O,P'k
DECLARE @LogicalFileName sysname, TS+itU62
@MaxMinutes INT, kzPHPERA]
@NewSize INT B4AV ubMbe
USE tablename -- 要操作的数据库名 `` (D01<
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 mKY}+21!Q
@MaxMinutes = 10, -- Limit on time allowed to wrap log. [)U|HnAJ
@NewSize = 1 -- 你想设定的日志文件的大小(M) KK"uSC
-- Setup / initialize `Q?rQ3A}
DECLARE @OriginalSize int P!yE{_%
SELECT @OriginalSize = size X%Jq9_
FROM sysfiles to~Ap=E
WHERE name = @LogicalFileName B3[;}8u>
SELECT 'Original Size of ' + db_name() + ' LOG is ' + #BLx +mLq
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + {[I]pm~n
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' e]9Z]a2
FROM sysfiles 9~7s*3zI
WHERE name = @LogicalFileName zf4\V F
CREATE TABLE DummyTrans 7\0}te
(DummyColumn char (8000) not null) _^%DfMP3i\
DECLARE @Counter INT, gT-"=AsxZQ
@StartTime DATETIME, -v@LJCK7I
@TruncLog VARCHAR(255) uM"_3je{W2
SELECT @StartTime = GETDATE(), _O,k0O
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' {sOW DM5
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ^-^ii3G`
EXEC (@TruncLog) qr@<'wp/
-- Wrap the log if necessary. I4"(4u@P
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired =&K8~
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) 7oy}<9
AND (@OriginalSize * 8 /1024) > @NewSize BjSd\Ul
BEGIN -- Outer loop. [d?tf
SELECT @Counter = 0 6*&$ha}X
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) =w5]o@
BEGIN -- update WGwIc7
INSERT DummyTrans VALUES ('Fill Log') pw.K,?kYr
DELETE DummyTrans ~T^,5Tz1j
SELECT @Counter = @Counter + 1 0$g;O5y"i
END cjp~I/U
EXEC (@TruncLog) \1ncr4
END 91#rP|88;
SELECT 'Final Size of ' + db_name() + ' LOG is ' + }vXiq T
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + :.P{}\/
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' Y*QoD9<T?;
FROM sysfiles hLICu[LC?
WHERE name = @LogicalFileName po!bRk[4
DROP TABLE DummyTrans JHXtKgFX
SET NOCOUNT OFF O=5q<7PM.
8、说明:更改某个表 B#;6z%WK
exec sp_changeobjectowner 'tablename','dbo' z -c1,GOD
9、存储更改全部表 iLt2L;v>h
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Nu;?})tF
@OldOwner as NVARCHAR(128), GIvl|
@NewOwner as NVARCHAR(128) Kw7uUJR
AS AM0CIRX$
DECLARE @Name as NVARCHAR(128) 8F
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DECLARE @Owner as NVARCHAR(128) d:Oo5t)MN
DECLARE @OwnerName as NVARCHAR(128) M?_7*o]!
DECLARE curObject CURSOR FOR R>t?6HOcp
select 'Name' = name, w
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'Owner' = user_name(uid) wEF"'T
from sysobjects 0j :u.x
where user_name(uid)=@OldOwner VkkC;/BBW
order by name G1a56TIN~
OPEN curObject l@0${&n
FETCH NEXT FROM curObject INTO @Name, @Owner '2Lx>nByk
WHILE(@@FETCH_STATUS=0) fuU
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BEGIN 0|DyYu
if @Owner=@OldOwner .L~
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begin jcp6-XM
set @OwnerName = @OldOwner + '.' + rtrim(@Name) >a;LBQ0
exec sp_changeobjectowner @OwnerName, @NewOwner A*~BkvPr
end mX%T"_^
-- select @name,@NewOwner,@OldOwner kni{1Gr
FETCH NEXT FROM curObject INTO @Name, @Owner QM'|k6
END Pm]lr|Q{I
close curObject h0
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deallocate curObject p}Um+I=1
GO UX'q64F!
10、SQL SERVER中直接循环写入数据 e'sS",o*
declare @i int I7\T :Q[
set @i=1 # w@FBFr@
while @i<30 h[;DRD!Z
begin Rk-G|52g
insert into test (userid) values(@i) {oS/Xa
set @i=@i+1 &]tm'N25
end K 6yD64
小记存储过程中经常用到的本周,本月,本年函数 'jXJ!GFw
Dateadd(wk,datediff(wk,0,getdate()),-1) !"ir}Y%
Dateadd(wk,datediff(wk,0,getdate()),6) CTe!jMZ=
Dateadd(mm,datediff(mm,0,getdate()),0) "=ki_1/P
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) oE_*hp+
Dateadd(yy,datediff(yy,0,getdate()),0) +k
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Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) 9C8 G(r
上面的SQL代码只是一个时间段 ]T{v~]7:{
Dateadd(wk,datediff(wk,0,getdate()),-1) K_n
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Dateadd(wk,datediff(wk,0,getdate()),6) +,g!xv4Q
就是表示本周时间段. G?, "AA;
下面的SQL的条件部分,就是查询时间段在本周范围内的: Q-B/SX)!/
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) GO.7IL{{
而在存储过程中 jZQ{XMF
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) Rt7l`|g a+
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) ]4r&Q4d>O