I have two models in my rails 5 application:
class Post < ApplicationRecord
has_many :tags
end
class Tag < ApplicationRecord
belongs_to :post
end
In my data base I have for example two post with 2 different tags each. How can I search my post by two specifics tags (tag.title="tagname1" AND tag.title="tagname2"):
Post.includes(:tags).where(tag: {title: "tagName1"}).where(tag: {title:
"tagName2"})
thanks
Post.joins(:tags)
.where(tags: { title: ['tag1', 'tag2'] })
.group('posts.id')
.having('count(tags.post_id) = ?', 2)
you have a uniqueness validation for tag.title for each post like the following:
class Tag < ApplicationRecord
belongs_to :post
validates :title, uniqueness: { scope: :post }
end
... otherwise, solution above won't work, because:
# it will still also match the following Post
Post(id: 1)
Tag(post_id: 1, title: 'tag1')
Tag(post_id: 1, title: 'tag1')
# but that you only want instead those like the following:
Post(id: 2)
Tag(post_id: 2, title: 'tag1')
Tag(post_id: 2, title: 'tag2')
You could use arel for cleaner queries.
Post.joins(:tags).where(Tag.arel_table[:title].in(['tagName1', 'tagName']))
OR operation when you use it like this. This is just SQL IN statement
search post by two specifics tags
Post.includes(:tags).where("tags.title IN (?)",["tagName1", "tagName"]).references(:tag)
This will return all posts having tags.title either "tagName1" or "tagName"
Post.includes(:tags).where("tags.title = ? AND ?","tagName1", "tagName").references(:tag) Probably this is what you want. ?