I am trying pull information from a contacts table based on multiple like conditions. So far I have come up with the following
conditions = ""
conditions << "email_address LIKE '%#{params[:email_address]}%'" unless params[:email_address].blank?
conditions << " AND first_name LIKE '%#{params[:first_name]}%'" unless params[:first_name].blank?
conditions << " AND last_name LIKE '%#{params[:last_name]}%'" unless params[:last_name].blank?
conditions.sub!(/^AND/, '')
if !conditions.blank?
#contacts = Contact.where(conditions).page(params[:page]).per(10)
else
#contacts = Contact.all.page(params[:page]).per(10)
end
What I was wondering is ... is this the best way to do this? I would have thought there would be a nice way to add multiple conditions in the form of a hash and somehow specify that I want to use OR/AND and like.
I am fairly new to rails and google is not really helping much.
Thanks.
Just append the where calls directly to a scope:
#contacts = Contact.scoped
#contacts = #contacts.where("email_address LIKE '%?%'", params[:email_address]) if params[:email_address].present?
#contacts = #contacts.where("first_name LIKE '%?%'", params[:first_Name]) if params[:first_name].present?
#contacts = #contacts.where("last_name LIKE '%?%'", params[:last_name]) if params[:last_name].present?
You can use a simple loop to make it less repetative:
%(email_address first_name last_name).each do |field|
#contacts = #contacts.where("#{field} like '%?%'", params[field]) if params[field].present?
end
And do not build queries by hand by directly substituting user input into your query string. Rails makes that hard to do on purpose: You're bypassing all of Rails' sanitization and opening yourself to SQL injection.
I would have thought there would be a nice way to add multiple conditions in the form of a hash and somehow specify that I want to use OR/AND and like.
There is, but it only works with AND and =:
#contacts.where(first_name: "bob", last_name: "smith")
# select ... where first_name = 'bob' and last_name = 'smith'
Related
I am trying to do a search with multiple attributes for Address at my Rails API.
I want to search by state, city and/or street. But user doesn't need to send all attributes, he can search only by city if he wants.
So I need something like this: if the condition exists search by condition or return all results of this condition.
Example:
search request: street = 'some street', city = '', state = ''
How can I use rails where method to return all if some condition is nil?
I was trying something like this, but I know that ||:all doesn't work, it's just to illustrate what I have in mind.:
def get_address
address = Adress.where(
state: params[:state] || :all,
city: params[:city] || :all,
street: params[:street] || :all)
end
It's possible to do something like that? Or maybe there is a better way to do it?
This is a more elegant solution using some simple hash manipulation:
def filter_addesses(scope = Adress.all)
# slice takes only the keys we want
# compact removes nil values
filters = params.permit(:state, :city, :street).to_h.compact
scope = scope.where(filters) if filters.any?
scope
end
Once you're passing a column to where, there isn't an option that means "on second thought don't filter by this". Instead, you can construct the relation progressively:
def get_address
addresses = Address.all
addresses = addresses.where(state: params[:state]) if params[:state]
addresses = addresses.where(city: params[:city]) if params[:city]
addresses = addresses.where(street: params[:street]) if params[:street]
addresses
end
I highly recommend using the Searchlight gem. It solves precisely the problem you're describing. Instead of cluttering up your controllers, pass your search params to a Searchlight class. This will DRY up your code and keep your controllers skinny too. You'll not only solve your problem, but you'll have more maintainable code too. Win-win!
So in your case, you'd make an AddressSearch class:
class AddressSearch < Searchlight::Search
# This is the starting point for any chaining we do, and it's what
# will be returned if no search options are passed.
# In this case, it's an ActiveRecord model.
def base_query
Address.all # or `.scoped` for ActiveRecord 3
end
# A search method.
def search_state
query.where(state: options[:state])
end
# Another search method.
def search_city
query.where(city: options[:city])
end
# Another search method.
def search_street
query.where(street: options[:street])
end
end
Then in your controller you just need to search by passing in your search params into the class above:
AddressSearch.new(params).results
One nice thing about this gem is that any extraneous parameters will be scrubbed automatically by Searchlight. Only the State, City, and Street params will be used.
I'm running a query like the below:
Item.where("created_at >=?", Time.parse(params[:created_at])).where(status_id: params[:status_id])
...where the user can decide to NOT provide a parameter, in which case it should be excluded from the query entirely. For example, if the user decides to not pass a created_at and not submit it, I want to run the following:
Item.where(status_id: params[:status_id])
I was thinking even if you had a try statement like Time.try(:parse, params[:created_at]), if params[created_at] were empty, then the query would be .where(created_at >= ?", nil) which would NOT be the intent at all. Same thing with params[:status_id], if the user just didn't pass it, you'd have a query that's .where(status_id:nil) which is again not appropriate, because that's a valid query in itself!
I suppose you can write code like this:
if params[:created_at].present?
#items = Item.where("created_at >= ?", Time.parse(params[:created_at])
end
if params[:status_id].present?
#items = #items.where(status_id: params[:status_id])
end
However, this is less efficient with multiple db calls, and I'm trying to be more efficient. Just wondering if possible.
def index
#products = Product.where(nil) # creates an anonymous scope
#products = #products.status(params[:status]) if params[:status].present?
#products = #products.location(params[:location]) if params[:location].present?
#products = #products.starts_with(params[:starts_with]) if params[:starts_with].present?
end
You can do something like this. Rails is smart in order to identify when it need to build query ;)
You might be interested in checking this blog It was very useful for me and can also be for you.
If you read #where documentation, you can see option to pass nil to where clause.
blank condition :
If the condition is any blank-ish object, then #where is a no-op and returns the current relation.
This gives us option to pass conditions if valid or just return nil will produce previous relation itself.
#items = Item.where(status_condition).where(created_at_condition)
private
def status_condition
['status = ?', params[:status]] unless params[:status].blank?
end
def created_at_condition
['created_at >= ?', Time.parse(params[:created_at])] unless params[:created_at].blank?
end
This would be another option to achieve the desired result. Hope this helps !
#matched = [1, 2, 3]
Where each integer represents the id of an ActiveRecord object in the Inventory class. As a next step, I want to look at each of those objects and obtain the email of the parent User, but I'm not sure how to do it. Ideally I'd write something like:
Inventory.where(id: #matched).user.email
Because certainly, this statement would work if I only had a single id to look up. Since that doesn't work, I'm instead doing this
#email = []
#matched.each do |i|
#email << Inventory.find_by_id(i).user.email
end
Just wondering if there's an easier way.
Thanks!
If you only need the email addresses then you can use the pluck method:
Inventory.where(id: #matched).joins(:user).pluck("users.email")
class Inventory
def self.with_ids(ids)
sql = #matched.map{|id| "id = #{id}"}.join(" OR ")
where(sql)
end
def parent_email
user.email
end
end
Inventory.with_ids(#matched).map(&:parent_email)
I'm implementing a search system that uses name, tags, and location. There is a has_and_belongs_to_many relationship between Server and Tag. Here's what my search method currently looks like:
def self.search(params)
#servers = Server.all
if params[:name]
#servers = #servers.where "name ILIKE ?", "%#{params[:name]}%"
end
if params[:tags]
#tags = Tag.find params[:tags].split(",")
# How do I eliminate servers that do not have these tags?
end
# TODO: Eliminate those that do not have the location specified in params.
end
The tags parameter is just a comma-separated list of IDs. My question is stated in a comment in the if params[:tags] conditional block. How can I eliminate servers that do not have the tags specified?
Bonus question: any way to speed this up? All fields are optional, and I am using Postgres exclusively.
EDIT
I found a way to do this, but I have reason to believe it will be extremely slow to run. Is there any way that's faster than what I've done? Perhaps a way to make the database do the work?
tags = Tag.find tokens
servers = servers.reject do |server|
missing_a_tag = false
tags.each do |tag|
if server.tags.find_by_id(tag.id).nil?
missing_a_tag = true
end
end
missing_a_tag
end
Retrieve the servers with all the given tags with
if params[:tags]
tags_ids = params[:tags].split(',')
#tags = Tag.find(tags_ids)
#servers = #servers.joins(:tags).where(tags: {id: tags_ids}).group('servers.id').having("count(*) = #{tags_ids.count}")
end
The group(...).having(...) part selects the servers with all requested tags. If you're looking for servers which have at least one of the tags, remove it.
With this solution, the search is done in a single SQL request, so it will be better than your solution.
I'm building a database application that tracks a lot of data for a Person, such as first_name, last_name, DOB, and 20+ more fields.
Users will need to be able to search for all of these fields. I'm having trouble writing clean code for this. The code below is what I have so far in my people_controller:
The data is submitted from a form_tag
def search
#people = Person.all
general_info_string = String.new
if(params[:first_name] != "") then general_info_string << 'people.first_name = "' + params[:first_name] + '" AND ' end
if(params[:last_name] != "") then general_info_string << "people.last_name = '" + params[:last_name] + "' AND " end
... Lots more of similar clauses
general_info_string = general_info_string[0, general_info_string.length - 5]
# ^This line removes the trailing " AND " from the string
#people = #people.where(general_info_string)
end
general_info_string is so called because there are more "where" clauses(not shown) and separate strings that I build to search for them.
The problem here is that the code looks like a mess and seems like a "hacky" way to do something that should be well supported by Rails. How could I perform this operation in a cleaner way?
That's not just hacky - it leaves you open to a string injection attack.
You need a :conditions using the ? template, like this example:
:conditions => ["key1 = ?", var]
but you need to make the template part into a string that grows once per parameter, and you need to make the var into an array that grows with each parameter's value. That gives you something like this:
template = []
values = []
if params[:first_name].present?
template.push 'people.first_name = ?'
values.push params[:first_name]
end
if params[:last_name].present?
template.push 'people.last_name = ?'
values.push params[:last_name]
end
template = template.join(' AND ')
:conditions => [template, *values]
From there, you should DRY up all those ifs, such as with a table of value keys. Then you'd loop through the table, check the key, and push its results into the arrays:
fields = [:first_name, :last_name, :shoe_size, ...]
fields.each do |field|
if params[field].present?
template.push "people.#{field} = ?"
values.push params[field]
end
end