具有必须唯一属性的两个对象数组的联合 - ruby

I have two activerecord models:

我有两个activerecord模型：

 class M1< ActiveRecord::Base

 end

 class M2< ActiveRecord::Base

 end

They both have the same structure, they have name and date and info attributes. I created 2 queries:

它们都具有相同的结构，它们具有名称，日期和信息属性。我创建了2个查询：

m1s = M1.where(...)
m2s = M2.where(...)

Now I want to union them one way or another.

现在我想以这种或那种方式结合它们。

So I do it simple:

所以我这么简单：

m_all=m1s + m2s

So I got an array of objects:

所以我得到了一个对象数组：

    [#<M1:0x007fffdcc14100
      date: Fri, 15 Sep 2017,
      name: "name1",
      info: "blablablabla">,

     #<M2:0x007fffdd492e08
      date: Fri, 15 Sep 2017,
      name: "name2",
      info: "blabla"> ...
   ]

And now from this array, I need to select objects, where (date, name) - combination of date and name properties is unique. In other words, I don't need repeated objects, that have the same date and the same name

现在从这个数组中，我需要选择对象，其中（日期，名称） - 日期和名称属性的组合是唯一的。换句话说，我不需要具有相同日期和相同名称的重复对象

For example if I have 3 records:

例如，如果我有3条记录：

 date="11.04.15" name="xxx" info =""
  date="11.04.15" name="yyy" info =""
  date="11.04.15" name="yyy" info = ""

It should select only the first two of them because second and third have the same date and name.

它应该只选择前两个，因为第二个和第三个具有相同的日期和名称。

So what do I do? I tried to do it like this but didn't work:

那我该怎么办？我试着像这样做，但没有奏效：

m_all= m_all.uniq do |m|
   [m[:date], m[:name]]
end

2 个解决方案

#1

I tried it on a sample database where I am, and the uniq code worked fine. Are you absolutely sure that date is a date field? If it's a datetime field you may be finding the matching fails for that.

我在我所在的示例数据库上尝试过，uniq代码工作正常。你绝对相信日期是一个日期字段吗？如果它是一个日期时间字段，您可能会发现匹配失败。

Try this to only match on year month day (I would also suggest to_date but I've occasionally had issues with that)

试试这个只匹配年月日（我也建议to_date，但我偶尔会遇到问题）

m_all= m_all.uniq do |m|
   [m[:date].to_datetime.strftime('%Y%m%d'), m[:name]]
end

#2

If I understand your requirement correctly, you need to use pluck:

如果我正确理解您的要求，您需要使用pluck：

Eg:

例如：

m1s = M1.where(...).pluck(:date, :name, :info)
m2s = M2.where(...).pluck(:date, :name, :info)

m_all = (m1s + m2s).uniq

Sample O/P

样品O / P.

[["11.04.15", "xxx", ""], ["11.04.15", "yyy", ""]]

NOTE: I tried to suggest it in comments but, since it's unreadable there, I posted it as answer.

注意：我试图在评论中提出建议但是，由于它在那里不可读，我将其作为答案发布。

EDIT

编辑

If you need the info with keys, the use select

如果您需要带密钥的信息，请使用select

m1s = M1.where(...).select(:date, :name, :info).as_json
m2s = M2.where(...).select(:date, :name, :info).as_json

m_all = (m1s + m2s).uniq

Sample O/P

样品O / P.

[{date: "11.04.15", name: "xxx", info: ""},
 {date: "11.04.15", name: "yyy", info: ""}]