1.设计原则 1) 标准化和规范化 数据的标准化有助于消除数据库中的数据冗余。标准化有好几种形式,但Third Normal Form(3NF)通常被认为在性能、扩展性和数据完整性方面达到了最好平衡。简单来说,遵守3NF 标准的数据库的表设计原则是:“One Fact in One Place”即某 ...
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数据库 时间:
2016-04-08 20:00:11
阅读次数:
307
Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place. Example Given a matrix [ [1,2], [0,3] ], return[[0,2],[0 ...
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其他好文 时间:
2016-04-06 07:06:05
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163
A common typing error is to place the hands on the keyboard one row to the right of the correct position. So ‘Q’ is typed as ‘W’ and ‘J’ is typed as ‘ ...
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其他好文 时间:
2016-04-05 19:31:31
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158
Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2- ...
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其他好文 时间:
2016-04-05 00:33:16
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175
Description For an electronic mail application you are to describe the SMTP-based communication that takes place between pairs of MTAs. The sender's U ...
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其他好文 时间:
2016-04-04 10:23:36
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202
一、结构 二、配置文件约定 The JPA provider automatically picks up this descriptor if you place it in a META-INF /orm.xml file on the classpath of the persistence ...
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编程语言 时间:
2016-04-03 17:35:45
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285
1. Description The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the "root." Besides the ...
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其他好文 时间:
2016-04-03 15:59:26
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175
var url = "https://maps.googleapis.com/maps/api/place/textsearch/json?query=chengdu&key=AIzaSyADem01JiuaQddzqagjdy41ep6SbhxBl8s"; var http = require(' ...
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Web程序 时间:
2016-04-02 13:37:59
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317
Question: Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place. Analysis: 给出一个m * n的矩阵,如果一个元素为0,则它整行整列都设为0. An ...
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其他好文 时间:
2016-03-31 23:32:16
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181
Question: Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1 ...
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其他好文 时间:
2016-03-29 21:21:49
阅读次数:
154