I have a form that when filled has to trigger a particular query, depending on which parameters the form has, so I have a method in my model that I believe should look like this:
def form_query(params)
query = ''
if params.has_key?('size')
query = query.where(size: params['size'])
end
if params.has_key?('title')
query = query.where(title: params['title'])
end
# More conditionals depending on params.
end
My question is, what does query have to be at the beginning? I put query = '', but I am wondering what has to be the base case, so I can conditionally add more 'where' clauses.
Queries aren't strings; they're query objects. So you want something like
query = YourModel.scoped # Rails 3; in Rails 4, use .all
if params.has_key?('size')
query = query.where(size: params['size'])
end
etc.
Alternatively, you can update your code as below:
def self.form_query(params)
options = {}
fields = ["body", "title"].freeze ## Add other options
if params.present?
fields.each do |field|
options[field] = params[field] if params[field]
end
end
if options.present?
where(options)
else
all ## or nil if you don't want to show any records in view
end
end
Also, form_query should be a class method in your model.
Add more options in the fields array that you would like to query against.
It not only makes your code compact but also makes a single database call.
Here is a more condensed version of Kirti Thorat's version:
FIELDS = ["size", "title"].freeze ## Add other options
def self.form_query(params)
return all unless params.present?
options = params.select { |k, _v| FIELDS.include? k.to_s }
options.present? ? where(options) : all
end
I have done k.to_s so you can pass params keys as either strings or symbols.
If you want to return nil if no params are passed you can do this:
FIELDS = ["size", "title"].freeze ## Add other options
def self.form_query(params)
return unless params.present?
options = params.select { |k, _v| FIELDS.include? k.to_s }
where(options) if options.present?
end
Related
I'm trying to build a simple search form in Ruby on Rails, my form is simple enough basically you select fields from a series of options and then all the events matching the fields are shown. The problem comes when I leave any field blank.
Here is the code responsible for filtering the parameters
Event.joins(:eventdates).joins(:categories).where
("eventdates.start_date = ? AND city = ? AND categories.name = ?",
params[:event][:date], params[:event][:city], params[:event][:category]).all
From what I get it's that it looks for events with any empty field, but since all of them have them not empty, it wont match unless all 3 are filled, another problem arises when I try to say, look events inside a range or array of dates, I'm clueless on how to pass multiple days into the search.
I'm pretty new to making search forms in general, so I don't even know if this is the best approach, also I'm trying to keep the searches without the need of a secialized model.
Below is probably what you are looking for. (Note: If all fields all blank, it shows all data in the events table linkable with eventdates and categories.)
events = Event.joins(:eventdates).joins(:categories)
if params[:event]
# includes below where condition to query only if params[:event][:date] has a value
events = events.where("eventdates.start_date = ?", params[:event][:date]) if params[:event][:date].present?
# includes below where condition to query only if params[:event][:city] has a value
events = events.where("city = ?", params[:event][:city]) if params[:event][:city].present?
# includes below where condition to query only if params[:event][:city] has a value
events = events.where("categories.name = ?", params[:event][:category]) if params[:event][:category].present?
end
To search using multiple days:
# params[:event][:dates] is expected to be array of dates.
# Below query gets converted into an 'IN' operation in SQL, something like "where eventdates.start_date IN ['date1', 'date2']"
events = events.where("eventdates.start_date = ?", params[:event][:dates]) if params[:event][:dates].present?
It will be more easy and optimised . If you use concern for filter data.
Make one concern in Model.
filterable.rb
module Filterable
extend ActiveSupport::Concern
module ClassMethods
def filter(filtering_params)
results = self.where(nil)
filtering_params.each do |key, value|
if column_type(key) == :date || column_type(key) ==
:datetime
results = results.where("DATE(#{column(key)}) = ?",
Date.strptime(value, "%m/%d/%Y")) if
value.present?
else
results = results.where("#{column(key)} Like ? ", "%#{value}%") if
value.present?
end
end
results
end
def resource_name
self.table_name
end
def column(key)
return key if key.split(".").count > 1
return "#{resource_name}.#{key}"
end
def column_type(key)
self.columns_hash[key].type
end
end
end
Include this concern in model file that you want to filter.
Model.rb
include Filterable
In your controller Add this methods
def search
#resources = Model.filter(class_search_params)
render 'index'
end
def class_search_params
params.slice(:id,:name) #Your field names
end
So, It is global solution. You dont need to use query for filter. just add this concern in your model file.
That's it.
I created a simple web form where users can enter some search criteria to look for venues e.g. a price range. When a user clicks "find" I use active record to query the database. This all works very well if all fields are filled in. Problems occur when one or more fields are left open and therefore have a value of null.
How can I work around this in my controller? Should I first check whether a value is null and create a query based on that? I can imagine I end up with many different queries and a lot of code. There must be a quicker way to achieve this?
Controller:
def search
#venues = Venue.where("price >= ? AND price <= ? AND romance = ? AND firstdate = ?", params[:minPrice], params[:maxPrice], params[:romance], params[:firstdate])
end
You may want to filter out all of the blank parameters that were sent with the request.
Here is a quick and DRY solution for filtering out blank values, triggers only one query of the database, and builds the where clause with Rails' ActiveRecord ORM.
This approach safeguards against SQL-injection, as pointed out by #DanBrooking. Rails 4.0+ provides "strong parameters." You should use the feature.
class VenuesController < ActiveRecord::Base
def search
# Pass a hash to your query
#venues = Venue.where(search_params)
end
private
def search_params
params.
# Optionally, whitelist your search parameters with permit
permit(:min_price, :max_price, :romance, :first_date).
# Delete any passed params that are nil or empty string
delete_if {|key, value| value.blank? }
end
end
I would recommend to make method in Venue
def self.find_by_price(min_price, max_price)
if min_price && max_price
where("price between ? and ?", min_price, max_price)
else
all
end
end
def self.find_by_romance(romance)
if romance
where("romance = ?", romance)
else
all
end
end
def self.find_by_firstdate(firstdate)
if firstdate
where("firstdate = ?", firstdate)
else
all
end
end
And use it in your controller
Venue
.find_by_price(params[:minPrice], params[:maxPrice])
.find_by_romance(params[:romance])
.find_by_firstdate(params[:firstdate])
Another solution to this problem, and I think a more elegant one, is using scopes with conditions.
You could do something like
class Venue < ActiveRecord::Base
scope :romance, ->(genre) { where("romance = ?", genre) if genre.present? }
end
You can then chain those, which would work as an AND if there is no argument present, then it is not part of the chain.
http://guides.rubyonrails.org/active_record_querying.html#scopes
Try below code, it will ignore parameters those are not present
conditions = []
conditions << "price >= '#{params[:minPrice]}'" if params[:minPrice].present?
conditions << "price <= '#{params[:maxPrice]}'" if params[:maxPrice].present?
conditions << "romance = '#{params[:romance]}'" if params[:romance].present?
conditions << "firstdate = '#{params[:firstdate]}'" if params[:firstdate].present?
#venues = Venue.where(conditions.join(" AND "))
I want to put each string from #enc into each field of column_name as a value
#enc=["hUt7ocoih//kFpgEizBowBAdxqqbGV1jkKVipVJwJnPGoPtTN16ZAJvW9tsi\n3inn\n", "wGNyaoEZ09jSg+/IclWFGAXzwz5lXLxJTUKqCFIiOy3ZXRgdwFUsNf/75R2V\nZm83\n", "MPq3KSzDzLvTeYh+h00HD+5FAgKoNksykJhzROVZWbIJ36WNoBgkSoicJ5wx\nog0g\n"]
Model.all.each do |row|
encrypted = #enc.map { |i| i}
row.column_name = encrypted
row.save!
end
My code puts all strings from array #enc into a single field?
I do not want that.
Help
Rails by default won't allow mass assignment. You have to whitelist parameters you want permitted. Have you tried doing something like the following?
#enc.each do |s|
cparams = create_params
cparams[:column_name] = s
Model.create(cparams)
end
def create_params
params.permit(:column_name)
end
You will need to specify the column names you are saving to. By setting each column separately you can also avoid mass-assignment errors:
#enc=["hUt7ocoih//kFpgEizBowBAdxqqbGV1jkKVipVJwJnPGoPtTN16ZAJvW9tsi\n3inn\n", "wGNyaoEZ09jSg+/IclWFGAXzwz5lXLxJTUKqCFIiOy3ZXRgdwFUsNf/75R2V\nZm83\n", "MPq3KSzDzLvTeYh+h00HD+5FAgKoNksykJhzROVZWbIJ36WNoBgkSoicJ5wx\nog0g\n"]
model = Widget.new
column_names = [:column1, :column2, :column3]
#enc.each_with_index do |s, i|
model[column_names[i]] = s
end
model.save
I think you are looking for something like this:
#enc.each do |str|
m = Model.new
m.column_name = str
m.save
end
I'm trying to write a query that will match last names that at least start with the submitted characters. No matter how I construct the query though, whether I use ILIKE, LIKE, ~*, or ##, the query that's constructed when the method is called from the controller changes the query to a simple = operator.
The full method:
def self.search(params)
if params.empty?
return Evaluation.none
end
results = nil
if params.include?(:appointment_start_date) && params.include?(:appointment_end_date)
results = Evaluation.where(appointment_time: params.delete(:appointment_start_date)..params.delete(:appointment_end_date))
end
params.each do |key, value|
case key
when :l_name
results = (results || Evaluation).where("to_tsquery('english', '#{value}:*') ## to_tsvector('english', l_name)")
when :ssn
results = (results || Evaluation).joins(:candidate).where(candidates: { ssn: value })
else
results = (results || Evaluation).where("#{key} = ?", value)
end
end
results.includes(:evaluation_type, :agency, :psychologist)
end
But the pertinent piece is:
.where("to_tsquery('english', '#{value}:*') ## to_tsvector('english', l_name)")
If I call the method from the Rails console, the expected SQL query is generated and the correct records are returned. Now here's the controller action:
def search
authorize! :read, Evaluation
#evaluations = Evaluation.search(evaluation_search_params).paginate(page: params[:page]).decorate
end
Let's say the user submits 'kel' for the search. For some flippin' reason, the generated query is
SELECT "evaluations".* FROM "evaluations" WHERE (l_name = 'kel') ORDER BY "evaluations"."appointment_time" ASC LIMIT 30 OFFSET 0
(There's a default_scope on Evaluation, hence the ORDER BY, so that's not part of the mystery.)
I've tried removing the pagination and the Draper decoration to no avail, and both of those also work fine in the console. So, my question is, why the heck is the generated query different when called from the controller? I'm seriously at my wit's end with this.
Are you param keys strings instead of symbols? That might be affecting which branch of the case statement is selected. Try debugging and stepping through the code if you are unsure.
You may just need to change to string values:
params.each do |key, value|
case key
when "l_name"
results = (results || Evaluation).where("to_tsquery('english', '#{value}:*') ## to_tsvector('english', l_name)")
when "ssn"
results = (results || Evaluation).joins(:candidate).where(candidates: { ssn: value })
else
results = (results || Evaluation).where("#{key} = ?", value)
end
end
I'm trying to chain criteria based on optional rails
parameters.
I want to be able to simultaneously filter based on selected tags as
well as searching.
Here is the current code that works in all situations:
if params[:tag] and params[:search]
#notes = Note.tagged_with_criteria(params[:tag]).full_text_search(params[:search])
elsif params[:tag]
#notes = Note.tagged_with_criteria(params[:tag])
elsif params[:search]
#notes = Note.full_text_search(params[:search])
end
I tried simply using
#notes = Note.tagged_with_criteria(params[:tag]).full_text_search(params[:search])
without the if statement, but then if only one of the params was
given, then all notes are returned.
Each of the methods (tagged_with_criteria and full_text_search) are
returning Note.criteria if their parameter is nil / empty.
Is there a simpler, more elegant way to chain Mongoid criteria like this?
I'd rather keep tacking on criteria one-by-one instead of having to do
the weird "if params[...] and params[...]" thing..
UPDATE: here are the current methods:
def tagged_with_criteria(_tags)
_tags = [_tags] unless _tags.is_a? Array
if _tags.empty?
criteria
else
criteria.in(:tags => _tags)
end
end
def self.full_text_search(query)
if query
begin
regex = /#{query}/
# supplied string is valid regex (without the forward slashes) - use it as such
criteria.where(:content => regex)
rescue
# not a valid regexp -treat as literal search string
criteria.where(:content => (/#{Regexp.escape(query)}/))
end
else
# show all notes if there's no search parameter
criteria
end
end
In a situation like that, I would modify the scopes to do nothing when passed in blank values.
I think what might be happening is you are getting empty strings from the params hash, which is causing your code to think that something was entered. Try the scopes with these edits.
def tagged_with_criteria(_tags)
_tags = Array.wrap(_tags).reject(&:blank?)
if _tags.empty?
criteria
else
criteria.in(:tags => _tags)
end
end
def self.full_text_search(query)
if query.present?
begin
regex = /#{query}/
# supplied string is valid regex (without the forward slashes) - use it as such
criteria.where(:content => regex)
rescue
# not a valid regexp -treat as literal search string
criteria.where(:content => (/#{Regexp.escape(query)}/))
end
else
# show all notes if there's no search parameter
criteria
end
end