Rails - Pass current_user into SQL query - sql

Question

I'm looking for a way to pass the Rails/Devise variable "current_user" into a SQL query.
I have an app with two models, Users and Tips. Users can friend other users and send tips to each other. I'm trying to display a user's friend list ordered by the number of tips that the user has sent to each friend, so that the friend to whom the user has sent the most tips shows up at the top of the friend list, and so on.
I've read that RoR isn't equipped to handle this kind of query easily, so I've been able to put together the following SQL query, which works fine:
def friend_list
#friends = User.find_by_sql("SELECT users.*,
COUNT(tips.id) AS c FROM users, tips
WHERE tips.recipient_id = users.id
AND tips.user_id = 3
GROUP BY users.id ORDER BY c DESC")
end
The only problem is, I have manually entered a user.id there ("3") when ideally that "3" would be replaced by "current_user" so that each time a user loads this list they get their friend list ranked by who they themselves have sent tips to, rather than everyone just seeing user 3's ranking.
In an ideal world this would look something like:
AND tips.user_id = current_user
but that doesn't work. How can I pass a variable into this query so that it is different for each person viewing?
UPDATE:
User model (excerpt):
has_many :tips
has_many :received_tips, :class_name => "Tip", :foreign_key => "recipient_id"
Tip model (excerpt):
belongs_to :user
belongs_to :recipient, :class_name => "User"

Answer 1

You cannot access current_user in models if using devise...though there are few good ways to do it
##method one---in your controller
#users=User.find(current_user.id)
##method two---in your controller
#users=User.get_user_details(current_user.id)
##in model
def self.get_user_details(current_user_id)
User.find(current_user_id)
end
###you can also use in this way in controller
#all_videos = Video.where("videos.user_id !=?",current_user.id)
.........so this can be your solution............
##in controller or pass current_user and user it in your model
def friend_list
#friends = User.joins(:tips).select("users.* and count(tips.id) as c").where ("tips.users_id= ?",current_user.id).group("users.id").order("c DESC")
##or
#friends = User.all(:joins => :tips, :select => "users.*, count(tips.id) as tips_count", :group => "users.id",:order=>"tips_count DESC")
end

Answer 2

You can try this
def friend_list
#friends = User.find_by_sql("SELECT users.*,
COUNT(tips.id) AS c FROM users, tips
WHERE tips.recipient_id = users.id
AND tips.user_id = ?
GROUP BY users.id ORDER BY c DESC", current_user.id)
end
Anyway it is not that hard to do this query using active_record.

Answer 3

I know this is old, but I want to add that you could also use string injection.
def friend_list
#Declare the query string you want to pass
#query = "SELECT users.*,
COUNT(tips.id) AS c FROM users, tips
WHERE tips.recipient_id = users.id
AND tips.user_id = #{current_user.id}
GROUP BY users.id ORDER BY DESC"
#friends = User.find_by_sql(#query)
end