Ruby-on-rails Rails ActiveRecord 条件
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Rails ActiveRecord conditions
提问by xpepermint
Is there a way to create a condition like this?
有没有办法创造这样的条件？
@products = Product.find(:all,
:limit => 5,
:conditions => { :products => { :locale => 'en', :id NOT '1' }, :tags => { :name => ['a','b']})
I would like to list all products not including product 1. Thx.
我想列出不包括产品 1 的所有产品。谢谢。
回答by Harish Shetty
Rails 3
导轨 3
Use squeelgem.
使用squeelgem。
Product.where(
:products => { :locale => 'en', :id.not_in => '1' },
:tags => { :name => ['a','b']}
).limit(5)
Rails 2
导轨 2
Use AR Extensionsfor this. It supports the following condition modifiers:
为此使用AR 扩展。它支持以下条件修饰符：
* _lt => less than
* _gt => greater than
* _lte => less than or equal to
* _gte => greater than or equal to
* _ne => not equal to
* _not => not equal to
Now you can rewrite your query as follows:
现在您可以按如下方式重写您的查询：
@products = Product.find(:all,
:limit => 5,
:joins => [:tags],
:conditions => { :locale => 'en', :id_not => '1', :tags => { :name => ['a','b']}
)
回答by user339798
Another way is to use the merge_conditions which turns the hash conditions into a string. Then you can add on whatever you want or call merge_conditions again with other options.
另一种方法是使用 merge_conditions 将哈希条件转换为字符串。然后您可以添加任何您想要的内容或使用其他选项再次调用 merge_conditions。
hash_conditions = {:category => 'computers'}
conditions = Product.merge_conditions(hash_conditions) + ' AND products.id NOT IN(1139) '
products = Product.find(:all, :conditions => conditions)
回答by Simone Carletti
It should be something like this. The original query wasn't really clear, adapt it to your needs.
它应该是这样的。原始查询不是很清楚，请根据您的需要进行调整。
@products = Product.find(:all,
:limit => 5,
:conditions => ["locale = ? AND id <> ? AND tags.name IN (?)", "en", 1, ['a','b'],
:joins => "tags"
)
回答by Rafael Perea
Rails 3.2.9
导轨 3.2.9
Controller
控制器
@products = Product.english_but_not(1).with_tags('a','b').limit(5)
Model
模型
class Product < ActiveRecord::Base
attr_accessible :locale
has_many :tags
scope :english, -> { where(:locale => 'en') }
scope :except_id, ->(id) { where(arel_table[:id].not_eq(id)) }
scope :english_but_not, ->(id) { english.except_id(id) }
scope :with_tags, ->(*names) { includes(:tags).where(:tags => {:name => names}) }
end
