I'll explain this as best as possible. I have a query on user posts:
#selected_posts = Posts.where(:category => "Baseball")
I would like to write the following statement. Here it is in pseudo terms:
User.where(user has a post in #selected_posts)
Keep in mind that I have a many to many relationship setup so post.user is usable.
Any ideas?
/EDIT
#posts_matches = User.includes(#selected_posts).map{ |user|
[user.company_name, user.posts.count, user.username]
}.sort
Basically, I need the above to work so that it uses the users that HAVE posts in selected_posts and not EVERY user we have in our database.
Try this:
user.posts.where("posts.category = ?", "Baseball")
Edit 1:
user.posts.where("posts.id IN (?)", #selected_posts)
Edit 2:
User.select("users.company_name, count(posts.id) userpost_count, user.username").
joins(:posts).
where("posts.id IN (?)", #selected_posts).
order("users.company_name, userpost_count, user.username")
Just use the following:
User.find(#selected_posts.map(&:user_id).uniq)
This takes the user ids from all the selected posts, turns them into an array, and removes any duplicates. Passing an array to user will just find all the users with matching ids. Problem solved.
To combine this with what you showed in your question, you could write:
#posts_matches = User.find(#selected_posts.map(&:user_id).uniq).map{ |user|
[user.company_name, user.posts.size, user.username]
}
Use size to count a relation instead of count because Rails caches the size method and automatically won't look it up more than once. This is better for performance.
Not sure what you were trying to accomplish with Array#sort at the end of your query, but you could always do something like:
#users_with_posts_in_selected = User.find(#selected_posts.map(&:user_id).uniq).order('username DESC')
I don't understand your question but you can pass an array to the where method like this:
where(:id => #selected_posts.map(&:id))
and it will create a SQL query like WHERE id IN (1,2,3,4)
By virtue of your associations your selected posts already have the users:
#selected_posts = Posts.where("posts.category =?", "Baseball")
#users = #selected_posts.collect(&:user);
You'll probably want to remove duplicate users from #users.
Related
Newbie Rails developer here so please bare with me.
I have a table called Ingredients where it contains a title field and an association to a User. A user can have many ingredients.
I want to query the database to get the ingredients that are not already available to a User.
I tried doing something like this with Rails:
#ingredients = current_user.ingredients
#community_ingredients = Ingredient.all.excluding(#ingredients).pluck(:title, :id)
But the problem is that this still returns values that are the same & only the case is different.
How can I achieve this outcome?
Try following queries.
#community_ingredients = Ingredient.includes(:user).where("users.user_id = ?", current_user.id).where(users: { id: nil } ).pluck(:title, :id)
OR
Ingredient.includes(:user).where("users.user_id = ?", current_user.id).where(ingredients: {user_id: nil } ).pluck(:title, :id)
OR
Ingredient.includes(:user).where("users.user_id = ?", current_user.id).where(users: { ingredient_id: nil } ).pluck(:title, :id)
Choose right query based on your association and feel free to suggest me so I can remove the extra one.
Most probably the first or second query will work, I strongly feel the third might not be the case.
Let's say this one is not working for you and you want to have solution based on your architecture.
#ingredients = current_user.ingredients.pluck(:title)
#community_ingredients = Ingredient.where.not("lower(title) IN (?)", #ingredients.map(&:downcase)).pluck(:title, :id)
So basically we need to convert both column value and the matching list in same case.
So we have converted to downcase.
here is how it looks in my local system, just make sure it's working that way.
I'm grabbing a list of users and storing in #users.
Now I need to find properties related to only this list of users I have queried.
if params[:company].present?
#users = User.where(parent_id: params[:company]).or(User.where(id: params[:company]))
##properties = #properties.where(user_id: params[:company])
end
I would basically like to include #users inside #properties.where()
I need to get each property that has a user_id present in my #users array
edit:
I just did the following which gives me the result, however, I'm sure there's a much better way of doing this via activerecord:
ids = []
#users.each do |user|
ids.push(user.id)
end
#properties = #properties.where(user_id: ids)
#properties.where(user_id: #users.ids)
That should work. It'll take the id of user ids and perform a filter using the IN clause.
Perhaps adding your models and their relationships we can think about something better.
I have an array #products. Each element of the array is a hash, containing a few fields (but not all) from Product table and the corresponding values.
I have a scope descend_by_popularity in Product which allows me to sort the products based on popularity field. I'd like to sort the array #products using this scope.
What I tried:
#product_group = Array.new
#products.each do |product|
#product_group.push(Product.find(product['id']))
end
#product_group1 = #product_group.descend_by_popularity
But this gives me error:
undefined method `descend_by_popularity' for #<Array:0xb2497200>
I also want to change the sorted Product list back to the format of #products array.
Thanks
Scopes only make sense within the ActiveRecord context for requests to the database (since it is used to change the SQL query). What you did is throwing a lot of products into an array. This array then knows nothing about the scope anymore. You would have to use the scope when you create the #products object. (and it does not seem to make a lot of sense to move the result of a query into an array)
So something like
#products = Product.descend_by_popularity.where(some more stuff)
should work for you. After that you should have the records in the order defined by the scope and can then either use them directly or still push them into an array if that's what you want to do.
With the updated info from the comments it looks like maybe the best way to go would be to first collect only the Product ids from the solr response into an array and then run that as search together with your scope:
#product_group = #products.map{|product| product.id}
#result = Product.where(id: #product_group).descend_by_popularity
this should technically work, peformance is a different question. I would consider aggregating this data into the Solr document, if it doesn't change too often.
Now assuming you are only interested in the order of products as such, you could do something like this to get #products into this order:
#result.map{|r| #products.find{|p| p[:id] == r.id}
though this may slow down things a bit.
Try this: find_by_id as params
#product_group = Array.new
#products.each do |product|
#product_group.push(Product.find(params['id']))
end
and return the array of #product_group
#product_group1 = #product_group.descend_by_popularity
I'd like to update the updated_at for a few records:
users = User.in_mailing_list
users.update_all(:updated_at => Time.now)
Is there a shortcut for the purpose, say something like a users.touch_all method?
Not sure if rhernando's answer works in older versions of Ruby, but this is a much clearer method in my opinion and works in Ruby 2+
users.each(&:touch)
NB. As mentioned in the comments this will cause N requests as opposed to using update_all which would do it in a single command.
You can do it like this:
User.update_all({updated_at: Time.now}, {id: user_ids})
Note: The braces are required, otherwise it tries to set updated_at and id, instead of updating updated_at where id is in user_ids
Cheers!
If you need touch ActiveRelaton records you have to use update_all method. It touches multiple records in a single transaction:
User.update_all(updated_at: Time.current)
User.where(active: true).update_all(active: false)
But if you have Array of records, in this case, you use only each with update
users.each { |user| user.update(active: true) }
the disadvantage of this case: for each user will be a separate transaction
Not sure since when but the solution is much simpler:
users = User.in_mailing_list
users.touch_all
Or if you don't want to instantiate the user records:
users = User.in_mailing_list.touch_all
This should do it:
User.update(users, :updated_at => Time.now)
I have a Search resource that returns posts based on a filter as described in Railscast111, and have the following code:
def filter_posts
posts = Post.order('created_at DESC')
posts = posts.where("name ilike ?", "%#{keywords}%")
posts = posts.where(... #numerous other filters
posts
end
The filter itself seems to work fine. However, the content is not always returned in order of 'created_at DESC'. How can I sort the final output so that it's always in order of 'created_at DESC'? Currently, there is no association between the Post and Search models. Do I need to build one? If so, how?
Have you tried chaining the two conditions together?
posts = Post.where("name like?", "%#{keywords}%").order('created_at DESC')
Depending on how many filters you end up calling, you'll need to keep updating your original result, with the updated scope (based on your filter), as each time you use where it creates a new scope, instead of adjusting the original one. So you seem to be on the right path, as your original code does this, e.g
posts = Post.where("filter1")
posts = posts.where("filter2")
Have you tried sorting after all of the filters have been applied, so something like
posts = posts.order('created_at DESC')
or
posts = posts.sort_by &:created_at
Also, I'm not really sure what you mean by a Search resource, when (at least in this case) it appears you could keep the search logic within the Post model itself. Can you clarify, or maybe post the model?