Ruby-on-rails Rails：查找所有条件

Rails: Find all with conditions

提问by Leahcim

in my app I have users from different countries and want to perform finds on them

在我的应用程序中，我有来自不同国家的用户，并希望对他们进行查找

I tried to do it like this in the index action

我试图在索引操作中这样做

 @fromcanada = User.find(:all, :country => 'canada')

but I got the error

但我得到了错误

 Unknown key: country

However, so that leads me to ask, what can become a key? In my database schema file, I have a "country" column on the users table.

然而，这让我想问，什么可以成为钥匙？在我的数据库架构文件中，我在用户表上有一个“国家”列。

t.string   "country"

Furthermore, when I did a find all

此外，当我找到所有

@users = User.all

I was able to do this

我能够做到这一点

<%= user.country %></p>

Can you explain why my find all with conditions didn't work? and show me how I should have done it?

你能解释一下为什么我的 find all with conditions 不起作用吗？告诉我我应该怎么做？

回答by Waynn Lue

Try this.

尝试这个。

@fromcanada = User.find(:all, :conditions => { :country => 'canada' })

edit: As jason328 pointed out, the above answer is deprecated in 3.2, and an updated answer would be

编辑：正如 jason328 所指出的，上述答案在 3.2 中已被弃用，更新的答案将是

@fromcanada = User.where(:country => 'canada')

回答by jason328

In case no one read the comments. A better format would be

万一没人看评论。更好的格式是

@fromcanada = User.where(country: 'canada').all

The previous answer's code is being deprecated in 3.2.

上一个答案的代码在 3.2 中已被弃用。

And for those using Rails 4, removing the allmethod will suffice.

对于那些使用 Rails 4 的人，删除该all方法就足够了。

@fromcanada = User.where(country: 'canada').to_a

Note that the to_acalls the query into an array format.

请注意，将to_a查询调用为数组格式。