How do I search by date in PGSQL?

I am getting this error:

ActionView::Template::Error (PGError: ERROR: operator does not exist: timestamp without time zone ~~ unknown LINE 1: ... "articles" WHERE ("articles"."created_at" LIKE '2010...

I have an archive controller where I can dynamically display articles by genre and year, month and day, with whichever of those fields are available in the url. In mysqlite, I had this index action:

def index
  filter_title
  @articles = Article.where(:created_at.matches % date_builder, :genre.matches % genre_builder).order("created_at DESC")
  respond_to do |format|
    format.json { render :json => @articles }
    format.xml  { 开发者_StackOverflow中文版render :xml => @articles }
    format.html
  end
end

And this date_builder function

def date_builder
  @date = ""
  @date += params[:year] if !(params[:year].nil?)
  @date += "-" + params[:month] if !(params[:month].nil?)
  @date += "-" + params[:day] if !(params[:day].nil?)
  @date += "%"
  @date
end

that would use metawhere to find dates that matched the part of the string that I supplied. This worked perfectly in Sqlite. I have migrated my application onto heroku and PGSQL, and it doesn't allow me to do this. What is the solution? Thank you!

In postgres, a timestamp is not stored as a string like in sqllite:

select 'A' where localtimestamp like '2011-04-04%';
ERROR:  operator does not exist: timestamp without time zone ~~ unknown

how about using >= instead?

select 'A' where localtimestamp >= '2011-04-04';

 ?column?
----------
 A
(1 row)

While I liked @JackPDouglas answer, I wanted to try and keep sql code out of my project as much as possible, so i ended up doing this:

...
date_builder
  if !(params[:year].nil?)
    @articles = Article.where(
      {:created_at.gt => @datelower} &
      {:created_at.lt => (@datehigher - 1.second)} &
      :genre.matches % genre_builder
      ).order("created_at DESC")
  else
...

and this method for the date:

def date_builder
  if !(params[:day].nil?)
    @datelower = Time.utc(params[:year], params[:month], params[:day])
    @datehigher = @datelower + 1.day
  elsif !(params[:month].nil?)
    @datelower = Time.utc(params[:year], params[:month], 01)
    @datehigher = @datelower + 1.month
  elsif !(params[:year].nil?)
    @datelower = Time.utc(params[:year], 01, 01)
    @datehigher = @datelower + 1.year
  end
end