Case-insensitive search in Rails model

You'll probably have to be more verbose here

name = "Blue Jeans"
model = Product.where('lower(name) = ?', name.downcase).first 
model ||= Product.create(:name => name)

You might want to use the following:

validates_uniqueness_of :name, :case_sensitive => false

Please note that by default the setting is :case_sensitive => false, so you don't even need to write this option if you haven't changed other ways.

Find more at: http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html#method-i-validates_uniqueness_of

In postgres:

 user = User.find(:first, :conditions => ['username ~* ?', "regedarek"])

Quoting from the SQLite documentation:

Any other character matches itself or its lower/upper case equivalent (i.e. case-insensitive matching)

...which I didn't know.But it works:

sqlite> create table products (name string);
sqlite> insert into products values ("Blue jeans");
sqlite> select * from products where name = 'Blue Jeans';
sqlite> select * from products where name like 'Blue Jeans';
Blue jeans

So you could do something like this:

name = 'Blue jeans'
if prod = Product.find(:conditions => ['name LIKE ?', name])
    # update product or whatever
else
    prod = Product.create(:name => name)
end

Not #find_or_create, I know, and it may not be very cross-database friendly, but worth looking at?

Similar to Andrews which is #1:

Something that worked for me is:

name = "Blue Jeans"
Product.find_by("lower(name) = ?", name.downcase)

This eliminates the need to do a #where and #first in the same query. Hope this helps!

An alternative can be

c = Product.find_by("LOWER(name)= ?", name.downcase)

Assuming that you use mysql, you could use fields that are not case sensitive: http://dev.mysql.com/doc/refman/5.0/en/case-sensitivity.html

You can use like this in model

scope :matching, lambda { |search, *cols|
    where cols.flatten.map{|col| User.arel_table[col].matches("%#{search}%") }.inject(:or)
}

and use wherever you like this

User.matching(params[:search], :mobile_number, :name, :email)

You can pass multiple column for search

for single column search you can use like this

User.where(User.arel_table[:column].matches("%#{search}%"))

So far, I made a solution using Ruby. Place this inside the Product model:

  #return first of matching products (id only to minimize memory consumption)
  def self.custom_find_by_name(product_name)
    @@product_names ||= Product.all(:select=>'id, name')
    @@product_names.select{|p| p.name.downcase == product_name.downcase}.first
  end

  #remember a way to flush finder cache in case you run this from console
  def self.flush_custom_finder_cache!
    @@product_names = nil
  end

This will give me the first product where names match. Or nil.

>> Product.create(:name => "Blue jeans")
=> #<Product id: 303, name: "Blue jeans">

>> Product.custom_find_by_name("Blue Jeans")
=> nil

>> Product.flush_custom_finder_cache!
=> nil

>> Product.custom_find_by_name("Blue Jeans")
=> #<Product id: 303, name: "Blue jeans">
>>
>> #SUCCESS! I found you :)