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。 NKSK+ll2
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一、基础 YcmLc)a7
1、说明:创建数据库 ~~B`\!n7
CREATE DATABASE database-name t++
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2、说明:删除数据库 5Y3L
drop database dbname l!d |luqbA
3、说明:备份sql server s2X<b
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--- 创建 备份数据的 device (v)/h>vS
USE master DD?zbN0X
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' }g9g]\.!a
--- 开始 备份 2}BQ=%E!'
BACKUP DATABASE pubs TO testBack rP7[{'%r
4、说明:创建新表 :;g7T -_q
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) P&=H<^yd
根据已有的表创建新表: C5F=J8pY
A:create table tab_new like tab_old (使用旧表创建新表) %aB
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B:create table tab_new as select col1,col2... from tab_old definition only jY +u OH
5、说明:删除新表 .,9e~6}
drop table tabname n|M~C\*
6、说明:增加一个列 {tDH !sX
Alter table tabname add column col type \Qgc7ev
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。 ;k=&ZV
7、说明:添加主键: Alter table tabname add primary key(col) c{,VU.5/
说明:删除主键: Alter table tabname drop primary key(col) Jqp;8DV}
8、说明:创建索引:create [unique] index idxname on tabname(col....) v]?zG&Jh
删除索引:drop index idxname "G[yV>pxv
注:索引是不可更改的,想更改必须删除重新建。 %`# HGji)
9、说明:创建视图:create view viewname as select statement ]Uu :t
删除视图:drop view viewname 9sI&&Jg
10、说明:几个简单的基本的sql语句 i[#XYX'\
选择:select * from table1 where 范围 |b+ZKRW
插入:insert into table1(field1,field2) values(value1,value2) !!\x]$v
删除:delete from table1 where 范围 8{f~tPY
更新:update table1 set field1=value1 where 范围 Gm.sl},
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! y[64O x
排序:select * from table1 order by field1,field2 [desc] b;5&V_
总数:select count as totalcount from table1 h6(\ tRd!\
求和:select sum(field1) as sumvalue from table1 (rE.ft5$9
平均:select avg(field1) as avgvalue from table1 ~85>.o2RDW
最大:select max(field1) as maxvalue from table1 xe&w.aBI>
最小:select min(field1) as minvalue from table1 t9\}!{<s
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11、说明:几个高级查询运算词 ^D5+S`V
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A: UNION 运算符 !K %8tr4
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 S11ME
B: EXCEPT 运算符 v[+ ]
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 _Oc(K
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C: INTERSECT 运算符 _wp_y-"
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 EZee
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注:使用运算词的几个查询结果行必须是一致的。 WZQ
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12、说明:使用外连接 7@NV|Idtd
A、left outer join: .dO8I/lhV
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 oO4hBM([
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c :?P>))vT%
B:right outer join: G&z^AV
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 q\n,/#'i~
C:full outer join: kc7,F2=F
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 t8ZzBD!dP
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二、提升 [lz#+~rOS
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) \n<9R8g5
法一:select * into b from a where 1<>1 /_[?i"GW
法二:select top 0 * into b from a /iw$\F |8
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 35KRJY#
insert into b(a, b, c) select d,e,f from b; :lBw0{fP
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) hCPyCq]
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 R
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例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. >n"4M~I
4、说明:子查询(表名1:a 表名2:b) [e f&|Pi-
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) ^iqy|zNtn
5、说明:显示文章、提交人和最后回复时间 |*%i]@V=
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b \#sdN#e;XA
6、说明:外连接查询(表名1:a 表名2:b) bamQ]>0|>!
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c _zK
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7、说明:在线视图查询(表名1:a ) P\ia ?9
select * from (SELECT a,b,c FROM a) T where t.a > 1; ]RxJ^'a63
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
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select * from table1 where time between time1 and time2 r]=Z :
select a,b,c, from table1 where a not between 数值1 and 数值2 =oT4!OUf
9、说明:in 的使用方法 qx1+'
select * from table1 where a [not] in ('值1','值2','值4','值6') ^e{]WH?
10、说明:两张关联表,删除主表中已经在副表中没有的信息 N#p%^GH
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) CxD=8X9m
11、说明:四表联查问题: ^ u:bgwP
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 ..... ZKTY1JW_
12、说明:日程安排提前五分钟提醒 8.zYa(<2
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 :ggXVwpe
13、说明:一条sql 语句搞定数据库分页 .(%]RSBY
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 | r,{# EE
14、说明:前10条记录 y!VL`xV
select top 10 * form table1 where 范围 PS3jCT
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.) BIXbdo5F
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) O<P(UT"
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 VVw5)O1'
(select a from tableA ) except (select a from tableB) except (select a from tableC) bk|?>yd
17、说明:随机取出10条数据 !<vy!pXg
select top 10 * from tablename order by newid() /d*[za'0
18、说明:随机选择记录 A=+1PgL66
select newid() iyv5\
19、说明:删除重复记录 6&;h+;h
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) #H]c/
20、说明:列出数据库里所有的表名 8/<+p? 3p>
select name from sysobjects where type='U' va2FgW`Bd+
21、说明:列出表里的所有的 ,*.qa0E#W
select name from syscolumns where id=object_id('TableName') &,tj.?NCn
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。 6>gm!6`
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 3Dx@rW\
显示结果: -
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type vender pcs 9Cs/B*3 )b
电脑 A 1 g=$nNQ
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电脑 A 1 (tCBbPW6T?
光盘 B 2 NpH9},1i
光盘 A 2 2 b80b50
手机 B 3 ny}_^3
手机 C 3 +xS<^;
23、说明:初始化表table1 ~NTKWRaR
TRUNCATE TABLE table1 Gc_KS'K@$
24、说明:选择从10到15的记录 uN=f(-"
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc i1 c[Gk.o
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三、技巧
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1、1=1,1=2的使用,在SQL语句组合时用的较多 SmUiH9qNd,
"where 1=1" 是表示选择全部 "where 1=2"全部不选, QYEGiT
如: K!8l!FFl
if @strWhere !='' ]sI\.a
begin \c1>15
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere xYY^tZIV
end >FS}{O2c
else K{9
begin +k V$ @qH
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' )"J1ET,z
end uFuP%f!yY
我们可以直接写成 !p Q*m`Xo
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 9&zQ5L>
2、收缩数据库 sJMpF8
--重建索引
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DBCC REINDEX VAp 1{
DBCC INDEXDEFRAG YIF|8b\
--收缩数据和日志
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DBCC SHRINKDB CIVV"p`}
DBCC SHRINKFILE ^iWJqpLe
3、压缩数据库 g"N&*V2
dbcc shrinkdatabase(dbname) +LlAGg]Z
4、转移数据库给新用户以已存在用户权限 I#'yy7J
exec sp_change_users_login 'update_one','newname','oldname' Dis kGq@T
go BKV:U\QZ
5、检查备份集 !AGoI7W}
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' d4) 0G-|
6、修复数据库 MkWbPm)
ALTER DATABASE [dvbbs] SET SINGLE_USER p^w_-(p
GO H`,t "I
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK b#*"eZj
GO .hjN*4RY
ALTER DATABASE [dvbbs] SET MULTI_USER K1w:JA6(
GO =
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7、日志清除 2J (nJT"
SET NOCOUNT ON 8Y_lQfJa
DECLARE @LogicalFileName sysname, ts;^,|h
@MaxMinutes INT, B%5"B} nG
@NewSize INT /4}y2JVv)
USE tablename -- 要操作的数据库名 cUO$IR)yL
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 \}AJ)v*<
@MaxMinutes = 10, -- Limit on time allowed to wrap log. $wbIe"|
@NewSize = 1 -- 你想设定的日志文件的大小(M) y,K> Wb9e
-- Setup / initialize gYloY=.Z$'
DECLARE @OriginalSize int gX|\O']6
SELECT @OriginalSize = size >vXS6`;
FROM sysfiles [
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WHERE name = @LogicalFileName 6Ilj7m*
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 4wWfaL5"
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + L\R(//V
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' 4>/i,_&K K
FROM sysfiles xZ(d*/6E
WHERE name = @LogicalFileName 53?Ati\Y)
CREATE TABLE DummyTrans mC3:P5/c
(DummyColumn char (8000) not null) R,fAl"wMu
DECLARE @Counter INT, "bz.nE*
@StartTime DATETIME, 03_M+lv
@TruncLog VARCHAR(255) AW'$5NF>
SELECT @StartTime = GETDATE(), wYDdy gS
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' .*Bd'\:F/q
DBCC SHRINKFILE (@LogicalFileName, @NewSize) {Es1bO
EXEC (@TruncLog) >U(E
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-- Wrap the log if necessary. !%B-y9\
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired oi8M6l
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) ge1U1o
AND (@OriginalSize * 8 /1024) > @NewSize (hh^?
BEGIN -- Outer loop. AmQsay#I_
SELECT @Counter = 0 P<;Puww/
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) EKS?3z%!
BEGIN -- update -J0OtrZ
INSERT DummyTrans VALUES ('Fill Log') B5+$VQ
DELETE DummyTrans 9i
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SELECT @Counter = @Counter + 1 v^;vH$B
END sXtt$HID=
EXEC (@TruncLog) "'XYW\bI
END {1+meE
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ":qS9vW
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + }h* j{b,
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' QU(Lv(/O
FROM sysfiles b`ksTO`}x
WHERE name = @LogicalFileName HBs
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DROP TABLE DummyTrans qIB2eCXw
SET NOCOUNT OFF ,1]VY/
8、说明:更改某个表 \FF|b"E_=
exec sp_changeobjectowner 'tablename','dbo' ",' Zr<T
9、存储更改全部表 V;Q@'<w
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch Wys$#pJ
@OldOwner as NVARCHAR(128), #4!f/dWJp
@NewOwner as NVARCHAR(128) l<'}`
AS $`R=Q
DECLARE @Name as NVARCHAR(128) U[:=7UABU?
DECLARE @Owner as NVARCHAR(128) )@] W=
DECLARE @OwnerName as NVARCHAR(128) Pn L?zae
DECLARE curObject CURSOR FOR w2jB6NQX
select 'Name' = name, zy.v[Y1!
'Owner' = user_name(uid) .- []po
from sysobjects ,b?G]WQrHs
where user_name(uid)=@OldOwner :a:m>S<~
order by name +n)bWB%
OPEN curObject *}_i[6_\E
FETCH NEXT FROM curObject INTO @Name, @Owner WI.+9$1:P
WHILE(@@FETCH_STATUS=0) %IDl+_j
BEGIN (`u+(M!^
if @Owner=@OldOwner .4[M-@4+]
begin ylDfr){
set @OwnerName = @OldOwner + '.' + rtrim(@Name) @}uo:b:Q
exec sp_changeobjectowner @OwnerName, @NewOwner 44KWS~
end j&b<YPZ
-- select @name,@NewOwner,@OldOwner _Y$v=!fY&
FETCH NEXT FROM curObject INTO @Name, @Owner C;#gy-
END P7REE_<1
close curObject M'oQ<,yW-
deallocate curObject Xn5LrLM&
GO c{39,oF
10、SQL SERVER中直接循环写入数据 ]7RK/Zu i
declare @i int nA%8
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set @i=1 XpA|<s
while @i<30 &)|f|\yh"
begin lwo,D}
insert into test (userid) values(@i) B B^81{A
set @i=@i+1 SRU#Y8Xv|
end 1v<uA9A%[
小记存储过程中经常用到的本周,本月,本年函数 W .Al\!Gi
Dateadd(wk,datediff(wk,0,getdate()),-1) V8b^{}nxt
Dateadd(wk,datediff(wk,0,getdate()),6) 1^[]#N-Bu
Dateadd(mm,datediff(mm,0,getdate()),0) =/ \l=*
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) *OHjw;xm+
Dateadd(yy,datediff(yy,0,getdate()),0) f9hH{(A
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) T+FlN-iy)
上面的SQL代码只是一个时间段 dEo r+5}
Dateadd(wk,datediff(wk,0,getdate()),-1) zm4e+v-
Dateadd(wk,datediff(wk,0,getdate()),6) m`b:#z
就是表示本周时间段. i98PlAq)B
下面的SQL的条件部分,就是查询时间段在本周范围内的: Ct:c%D(L
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) Tz7 R:S.
而在存储过程中 1{
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select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) . TNJuuO
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) Zc*#LsQh.`