Is there a way to generate a less than or greater than query in rails like the between range query. I have multiple query params and hence I do not want to use string literal for comparison.
if params["end_time"]
if params["start_time"]
params["end_time"] = params["end_time"].to_datetime
query[:created_at] = ((params["start_time"])..params["end_time"])
else
query[:created_at] = #Need help with this
end
end
def with_duration
if(params['start_time'] && params['end_time'])
{created_at: params['start_time']..params['end_time']}
elsif(params['start_time'])
return ["created_at > ?", "#{params['start_time']}"]
elsif(params['end_time'])
return ["created_at < ?", "#{params['end_time']}"]
else
return {}
end
end
ModelName.where(with_duration)
As I understood you need to do nothing if params empty. So you can try this implementation.
def query_method(scope)
return scope unless params["end_time"] && params["start_time"]
scope.where.not(created_at: (params["start_time"]..params["end_time"]))
end
Related
I'm trying to figure out a better way to have one query here. I want to be able to send something to last where statement a wildcard so I can select all vendors. Right now if i don't include that line it doesn't filter by vendor so I essentially get all the purchase requests.
Any thoughts of a cleaner way to do these sorts of queries?
if #vendor == "0" #checks for vendor
#purchase_requests = PurchaseRequest.includes(:purchase_order)
.where(:created_at => #date_start..#date_end)
.where(:total_cost => #cost_beginning..#cost_end)
else
#purchase_requests = PurchaseRequest.includes(:purchase_order)
.where(:created_at => #date_start..#date_end)
.where(:total_cost => #cost_beginning..#cost_end)
.where("purchaseorder.VendorRef_ListID = ?", #vendor)
end
there must be some better solution, but try this
#purchase_requests = PurchaseRequest.includes(:purchase_order).where(created_at: #date_start..#date_end, total_cost: #cost_beginning..#cost_end)
#purchase_requests = #purchase_requests.where("purchaseorder.VendorRef_ListID = ?", #vendor) unless #vendor == "0"
Here is a simplified version:
#purchase_requests = PurchaseRequest
.includes(:purchase_order)
.where(created_at: #date_start..#date_end)
.where(total_cost: #cost_beginning..#cost_end)
#purchase_requests = #purchase_requests.where('purchase_orders.VendorRef_ListID = ?', #vendor) unless #vendor == '0'
I need to filter objects in array.
It works with one parameters
#usersc = #usersb.select { |user| user.need_appartment? }
but i would like use more parameters than in SQL/ActiveRecord :
(need_bedrooms_min >= :nb_bedrooms_min) AND (budget_amount BETWEEN :budget_min AND :budget_max) AND ((need_surface_min BETWEEN :surface_min AND :surface_max) OR (need_surface_max BETWEEN :surface_min AND :surface_max))"+req,{nb_bedrooms_min: params[:nb_bedrooms_min], budget_min: params[:budget_min], budget_max: params[:budget_max],surface_min: params[:surface_min], surface_max: params[:surface_max]}).paginate(:page => params[:page])
I dont find the solution... Anyone can help me ?
F.
select does exactly what you need with as many parameters as you might want:
#usersb.select do |user|
user.need_bedrooms_min >= params[:nb_bedrooms_min].to_i &&
(params[:budget_min].to_i..params[:budget_max].to_i).include? user.budget_amount &&
((params[:surface_min].to_i..params[:surface_max].to_i).include? user.need_surface_min ||
(params[:surface_min].to_i..params[:surface_max].to_i).include? user.need_surface_max)
end
Or, more cleanly:
class User
def needs_apartment?(params)
budget_min, budget_max, surface_min, surface_max, nb_bedrooms_min =
%w{budget_min budget_max surface_min surface_max nb_bedrooms_min}.map{|k| params[k.to_sym].to_i}
budget_range = budget_min..budget_max
surface_range = surface_min..surface_max
need_bedrooms_min >= nb_bedrooms_min &&
budget_range.include? budget_amount &&
(surface_range.include?(need_surface_min) || surface_range.include?(need_surface_max))
end
end
#usersb.select{|user| user.needs_apartment?(params)}
In my Rails 4 app, I defined functions in my model than get the (nth) next or previous row in de database, wrapping around the entire database, so that Item.last.next will refer to Item.first:
def next(n=0)
following = Item.where("id > ?", self.id).order("id asc") + Item.where("id < ?", self.id).order("id asc")
following[n % following.length]
end
def prev(n=0)
n = n % Item.count-1
previous = Item.where("id < ?", self.id).order("id desc") + Item.where("id > ?", self.id).order("id desc")
previous[n % previous.length]
end
This results in three database queries per method call, and I've learned to keep database queries to a minimum, so I wonder if there is a way do get this result with only one query.
What you are looking for seems a bit high level. So let's prepare the basic API at first.
def next(n=1)
self.class.where('id > ?', id).limit(n).order('id ASC')
end
def previous(n=1)
self.class.where('id > ?', id).limit(n).order('id DESC')
end
Then higher level methods
def next_recycle(n=1)
klass = self.class
return klass.first if (n = 1 && self == klass.last)
next(n)
end
def previous_recycle(n=1)
klass = self.class
return klass.last if (n == 1 && self == klass.first)
previous(n)
end
You can pick methods according to needs.
I would like to simplify this complicated logic for creating unique Track object.
def self.create_unique(p)
f = Track.find :first, :conditions => ['user_id = ? AND target_id = ? AND target_type = ?', p[:user_id], p[:target_id], p[:target_type]]
x = ((p[:target_type] == 'User') and (p[:user_id] == p[:target_id]))
Track.create(p) if (!f and !x)
end
Here's a rewrite of with a few simple extract methods:
def self.create_unique(attributes)
return if exists_for_user_and_target?(attributes)
return if user_is_target?(attributes)
create(attributes)
end
def self.exists_for_user_and_target?(attributes)
exists?(attributes.slice(:user_id, :target_id, :target_type))
end
def self.user_is_target?(attributes)
attributes[:target_type] == 'User' && attributes[:user_id] == attributes[:target_id]
end
This rewrite shows my preference for small, descriptive methods to help explain intent. I also like using guard clauses in cases like create_unique; the happy path is revealed in the last line (create(attributes)), but the guards clearly describe exceptional cases. I believe my use of exists? in exists_for_user_and_target? could be a good replacement for find :first, though it assumes Rails 3.
You could also consider using uniqueness active model validation instead.
##keys = [:user_id, :target_id, :target_type]
def self.create_unique(p)
return if Track.find :first, :conditions => [
##keys.map{|k| "#{k} = ?"}.join(" and "),
*##keys.map{|k| p[k]}
]
return if p[##keys[0]] == p[##keys[1]]
return if p[##keys[2]] == "User"
Track.create(p)
end
I am working on an events application where i want to filter events depending on the 3 parameters location or starts_at or ends_at in the query string. There can be any one, two or all the parameters in the query string. In i use if-else statement i need to make 6 cases which will make my code clumsy. Rather i am thinking to implement something this way:
class EventsController < ApplicationController
def index
unless params.empty?
unless params[:location].nil?
#events = Event.where("location = ?", params[:location])
end
unless params[:starts_at].nil?
unless #events.empty?
#events = #events.where("start_date = ?", params[:start_date])
else
#events = Event.where("Date(starts_at) = Date(?)", params[:starts_at])
end
end
unless params[:ends_at].nil?
unless #events.empty?
#events = #events.where("end_date = ?", params[:end_date])
else
#events = Event.where("Date(ends_at) = Date(?)", params[:ends_at])
end
end
end
end
end
But this code doesnt work since where query doen not work on an array. Can someone suggest me some solution for this..
You should be able to pass your params hash directly to where, and it will form the correct SQL based on the keys and values of that hash:
Event.where(params)
An example in the console:
1.9.3p194 :001 > puts Example.where(:location => 'here', :started_at => '2012-08-13').to_sql
SELECT "examples".* FROM "examples" WHERE "examples"."location" = 'here' AND "examples"."started_at" = '2012-08-13'
Try Following
def index
unless params.empty?
where_array, arr = [], []
if params[:location]
where_array << "location = ?"
arr << params[:location]
end
if params[:starts_at]
where_array << "start_date = ?"
arr << params[:starts_at]
end
if params[:ends_at]
where_array << "end_date = ?"
arr << params[:ends_at]
end
#events = arr.blank? ? [] : Event.where([where_array.join(" AND "), *arr])
end
end