https://blog.youkuaiyun.com/bit_xzh-cnhttps://blog.youkuaiyun.com/https://blog.youkuaiyun.com/bit_x/article/details/20390183https://blog.youkuaiyun.com/bit_x/article/details/20390183bit_xMon, 03 Mar 2014 18:21:34 +0800https://blog.youkuaiyun.com/bit_x/article/details/20129841https://blog.youkuaiyun.com/bit_x/article/details/20129841bit_xFri, 28 Feb 2014 12:57:03 +0800https://blog.youkuaiyun.com/bit_x/article/details/18663561https://blog.youkuaiyun.com/bit_x/article/details/18663561bit_xWed, 22 Jan 2014 15:53:34 +0800https://blog.youkuaiyun.com/bit_x/article/details/17286599https://blog.youkuaiyun.com/bit_x/article/details/17286599bit_xThu, 12 Dec 2013 18:13:23 +0800https://blog.youkuaiyun.com/bit_x/article/details/12967343https://blog.youkuaiyun.com/bit_x/article/details/12967343bit_xWed, 13 Nov 2013 10:53:29 +0800https://blog.youkuaiyun.com/bit_x/article/details/15809661https://blog.youkuaiyun.com/bit_x/article/details/15809661bit_xWed, 13 Nov 2013 10:49:26 +0800https://blog.youkuaiyun.com/bit_x/article/details/12910259https://blog.youkuaiyun.com/bit_x/article/details/12910259bit_xTue, 22 Oct 2013 13:56:03 +0800https://blog.youkuaiyun.com/bit_x/article/details/12851571https://blog.youkuaiyun.com/bit_x/article/details/12851571bit_xFri, 18 Oct 2013 16:09:33 +0800https://blog.youkuaiyun.com/bit_x/article/details/12837153https://blog.youkuaiyun.com/bit_x/article/details/12837153bit_xThu, 17 Oct 2013 15:36:53 +0800>，各二进制全部向右移位，对于无符号数，低位丢失，高位补零；有符号数个编译器不同，有的补符号位，有的补0； 二、技巧用途]]>https://blog.youkuaiyun.com/bit_x/article/details/9417665https://blog.youkuaiyun.com/bit_x/article/details/9417665bit_xTue, 23 Jul 2013 09:48:20 +0800https://blog.youkuaiyun.com/bit_x/article/details/9417483https://blog.youkuaiyun.com/bit_x/article/details/9417483bit_xTue, 23 Jul 2013 09:24:21 +0800https://blog.youkuaiyun.com/bit_x/article/details/9412113https://blog.youkuaiyun.com/bit_x/article/details/9412113bit_xMon, 22 Jul 2013 18:17:17 +0800https://blog.youkuaiyun.com/bit_x/article/details/5973898https://blog.youkuaiyun.com/bit_x/article/details/5973898bit_xFri, 29 Oct 2010 12:39:00 +0800[AS3] 移除物件和事件問題
http://www.walkone.com.tw/blog/?user_id=justdoit&subject_id=6521
 ]]>https://blog.youkuaiyun.com/bit_x/article/details/5887903https://blog.youkuaiyun.com/bit_x/article/details/5887903bit_xThu, 16 Sep 2010 11:19:00 +0800支持sql的RDBMS同时都支持关系数据库的三种模型外模式对应于视图和部分基本表模式对应于基本表内模式对应于存储文件
 ]]>https://blog.youkuaiyun.com/bit_x/article/details/5887902https://blog.youkuaiyun.com/bit_x/article/details/5887902bit_xThu, 16 Sep 2010 11:19:00 +0800https://blog.youkuaiyun.com/bit_x/article/details/5887761https://blog.youkuaiyun.com/bit_x/article/details/5887761bit_xThu, 16 Sep 2010 10:34:00 +0800
连接：从两个关系的笛卡尔积中选择属性间满足一定条件的元组
等值连接：从关系R和S的广义笛卡尔积中选择属性A和B相等的元组
自然连接：是一种特殊的等只连接，要求两个关系中进行比较的分量必须有相同的属性列，并且在结果中把重复的属性列去掉
 
两个关系R和S在做自然连接时，选择两个关系在公共属性上值相等的元组构成新的关系。此时，R中某些元组有可能在S中不存在公共属性上值相等的元组，从而造成R中某些元组有可能在S中不存在公共属性上值相等的元组，从而造成]]>https://blog.youkuaiyun.com/bit_x/article/details/5886550https://blog.youkuaiyun.com/bit_x/article/details/5886550bit_xWed, 15 Sep 2010 17:32:00 +0800https://blog.youkuaiyun.com/bit_x/article/details/5886491https://blog.youkuaiyun.com/bit_x/article/details/5886491bit_xWed, 15 Sep 2010 17:19:00 +0800第一范式（1NF）无重复的列
所谓第一范式（1NF）是指数据库表的每一列都是不可分割的基本数据项，同一列中不能有多个值，即实体中的某个属性不能有多个值或者不能有重复的属性。
 
第二范式（2NF）属性完全依赖于主键[消除部分子函数依赖]
第二范式（2NF）是在第一范式（1NF）的基础上建立起来的，即满足第二范式（2NF）必须先满足第一范式（1NF）。第二范式（2NF）要求数据库表中的每个实例或行必须可以被惟一地区分。
 
第三范式（3N]]>https://blog.youkuaiyun.com/bit_x/article/details/5885415https://blog.youkuaiyun.com/bit_x/article/details/5885415bit_xWed, 15 Sep 2010 10:53:00 +0800http://forum.ubuntu.org.cn/viewtopic.php?f=43&t=203541
http://wiki.ubuntu.org.cn/Apache]]>https://blog.youkuaiyun.com/bit_x/article/details/5883841https://blog.youkuaiyun.com/bit_x/article/details/5883841bit_xTue, 14 Sep 2010 16:19:00 +0800
SELECT语句的执行的逻辑查询处理步骤：
 
(8)SELECT (9)DISTINCT
(11)
(1)FROM
(3)　 JOIN
(2)　 ON
(4)WHERE
(5)GROUP BY ]]>