Rails 虚拟属性搜索或 sql 组合列搜索 [英] Rails virtual attribute search or sql combined column search

问题描述

我有一个具有first"和last"属性的用户模型所以例如User.first.first #=>查理"用户.first.last #=>棕色"

I have a user model with attributes 'first' and 'last' So for example User.first.first #=> "Charlie" User.first.last #=> "Brown"

这个用户模型还有一个虚拟属性'full_name'

This User model also has a virtual attribute 'full_name'

#user.rb
def full_name
  [first,last].join(' ')
end

def full_name=(name) #don't know what to do with people w/ middle names
  split = name.split(' ')
  self.first = split[0]
  self.last = split[1]
end

例如:

User.first.full_name = "Charlie Brown" #=> "Charlie Brown"
User.first.full_name = "Homer Simpson" #=> "Home Simpson"
User.first.save
User.first.first #=> "Homer"
User.first.last #=> "Simpson"

如果我能按那个虚拟属性搜索就好了例如动态查找:

It'd be so nice if I could search by that virtual attribute so for example for dynamic find:

User.find_by_full_name('Home Simpson') # this doesn't work

查找条件示例:

User.all(:conditions => ['full_name LIKE ?', query]) #this doesn't work

我希望至少能在 SQL 语言中找到一些可以做到这一点的方法；如果也有动态虚拟属性查找，那就是馅饼上的额外香草来源.(今年冬天有人过吗?)

I am hoping to find at least some ways in SQL language that can do this; if there's a dynamic virtual attribute find, too, that's extra vanilla source on the strudel. (anyone having this this winter?)

我还担心被搜索的名字，例如Holmes".只能在 'first' 列中搜索，而不是在 'last' 中检索，例如 User.first.full_name #=>夏洛克·福尔摩斯".

I was also concerned about a name being searched , e.g., "Holmes" may only be searched in the 'first' column but not the 'last' to retrieve, for example, User.first.full_name #=> "Sherlock Holmes".

我确实尝试进行更全面的搜索:

I did try to do a more comprehensive search:

def self.find_by_full_name(name) #returns an array of User model
  return all if name.blank?
    
  split = name.split(' ', 2)
  output = []
  if split.length > 1
    with_scope( :find => { :conditions => ['first LIKE ?', "%#{split[0]}%"] }) do
      output << all(:conditions => ['last LIKE ?', "%#{split[1]}%"])
      output.flatten!
    end
  elsif split.length == 1
    output << all(:conditions => ['first LIKE ?', "%#{split[0]}%"])
    output << all(:conditions => ['last LIKE ?', "%#{split[0]}%"])
    output.flatten!
  end
end

例如

User.find_by_full_name("John").map(&:full_name) #=> ["John Resig", "John Doe"]
User.find_by_full_name("Doe").map(&:full_name) #=> ["John Doe", "Philips Doeringer"]
User.find_by_full_name("John Doe").map(&:full_name) #=> ["John Doe"]

但我只是觉得这里的 find_by_full_name 方法有点笨拙.

But I just thought that the find_by_full_name method here is a bit unwieldy.

我的意思是，如果我有一个 full_name 列，它每次都由一个后保存过滤器设置，并带有 first 和 last 的 concat.所以找到一个人的名字，尤其是对这个人的模糊记忆，是有帮助的.因此，如果我记得那个人的名字或姓氏中的Doe"，我总是可以做一个简单的 User.find_by_full_name('Doe') 来返回尽可能多的信息以进一步确定它.

I mean, if I had a column full_name that gets set each time by a after save filter with the concat of first and last. So finding a person's name, especially with fuzzy memory of this person, is helpful. So if I remembered 'Doe' in that person's either first or last name, I can always do a simple User.find_by_full_name('Doe') to return as many as possible to further pin it down.

由于它是一列，如果我必须执行类似 Project.find(:all,:include => 之类的操作，我可以在 find(:conditions[...]) 子句中搜索它:users, :conditions=>['users.full_name LIKE ?', query])在哪里

And since it is a column, I can search it in a find(:conditions[...]) clause if I have to do something like Project.find(:all,:include => :users, :conditions=>['users.full_name LIKE ?', query]) where

#project.rb
has_many :assignments
has_many :users, :through=>:assignments

#user.rb
has_many :assignments
has_many :projects, :through => :assignments

#assignment.rb
belongs_to :user
belongs_to :project

节日快乐否

推荐答案

你可以在你的user.rb中使用named_scope:

You can used a named_scope in your user.rb:

named_scope :find_by_full_name, lambda {|full_name| 
  {:conditions => {:first => full_name.split(' ').first, 
     :last => full_name.split(' ').last}}
}

然后你可以做 User.find_by_full_name('John Carver')

响应需求变化的新东西

named_scope :find_by_full_name, lambda {|full_name| 
  {:conditions => ["first LIKE '%?%' or last LIKE '%?%'", 
    full_name.split(' ').first, full_name.split(' ').last]}}

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