class Customer < ActiveRecord::Base has_many :ordersendclass Order < ActiveRecord::Base belongs_to :customerend如上代码两个model在做如下查询的时候：c = Customer.fir.....
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其他好文 时间：
2014-07-10 10:03:57
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293
译者注：这是原文地址。另外，关键的单词我保留原文】作者：Hasselt University -Expertise Centre for Digital Media1. 引言这个是 EMIPLIB 的说明手册，EMIPLIB 即 EDM Media over IP libray。这个库开发于 Has...
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其他好文 时间：
2014-07-10 00:54:22
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273
QEMU Networking QEMU has a number of really nice ways to set up networking for its guests. It can be a little bewildering to figure out how each of th...
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Web程序 时间：
2014-07-10 00:32:27
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499
Given an array of words and a length L, format the text such that each line has exactly L characters and is fully (left and right) justified.
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其他好文 时间：
2014-07-07 23:16:20
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274
users: EntityType: EntitySet 'users' is based on type 'UserModel' that has no keys defined.TreeLayer.DAL.UserModel: : EntityType 'UserModel' has no ke...
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数据库 时间：
2014-07-07 22:20:05
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620
StackOverflowhttp://stackoverflow.com/a/7059499Question:I have aUIScrollViewthat has a series of labels which are rapidly updating numbers (every .06 ...
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移动开发 时间：
2014-07-07 22:02:50
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330
KVM I/O slowness on RHEL 6 http://www.ilsistemista.net/index.php/virtualization/11-kvm-io-slowness-on-rhel-6.html?limitstart=0 Over one year has passe...
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其他好文 时间：
2014-07-07 20:21:46
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397
Problem Description:Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equ...
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其他好文 时间：
2014-07-07 19:03:39
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165
From gtk+-2.90.7 configure --help we can see:--with-gdktarget=[x11/win32/quartz] select non-default GDK targetThere is no directfb in the gdktarget as...
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其他好文 时间：
2014-07-07 18:22:03
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235
The default music player on Debian 7.0 is Rhythmbox. At the first look, its appearance seems not so bad. Although it has the problem of displaying Chi...
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系统相关 时间：
2014-06-30 13:15:51
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406
