The script I used to import posts from my Wordpress blog into a new Jekyll one.

Importing posts from Wordpress into Jekyll.rb

%w(rubygems sequel fileutils yaml active_support/inflector).each{|g| require g}

require File.join(File.dirname(__FILE__), "downmark_it")

module WordPress
  def self.import(database, user, password, table_prefix = "wp_2", host = 'localhost')
    db = Sequel.mysql(database, :user => user, :password => password, :host => host, :encoding => 'utf8')

    FileUtils.mkdir_p "_posts"

    query = <<-EOS

      SELECT post_title, post_name, post_date, post_content, post_excerpt, ID, guid
      FROM   #{table_prefix}_posts AS post
      WHERE  post_type = 'post'

    EOS

    categories_and_tags_query = <<-EOS

      SELECT      t.taxonomy, term.name, term.slug
      FROM        #{table_prefix}_term_relationships AS tr
      INNER JOIN  #{table_prefix}_term_taxonomy AS t ON t.term_taxonomy_id = tr.term_taxonomy_id
      INNER JOIN  #{table_prefix}_terms AS term ON term.term_id = t.term_id
      WHERE       tr.object_id = %d AND t.taxonomy != 'link_category'

    EOS

    db[query].each do |post|
      title      = post[:post_title]
      slug       = post[:post_name]
      date       = post[:post_date]
      content    = DownmarkIt.to_markdown post[:post_content]
      name       = "%02d-%02d-%02d-%s.markdown" % [date.year, date.month, date.day, slug]
      categories = []
      post_tags  = []

      puts title

      db[categories_and_tags_query % post[:ID]].each do |category_or_tag|
        eval(category_or_tag[:taxonomy].pluralize) << {
          "title"    => category_or_tag[:name],
          "slug"     => category_or_tag[:slug]
        }
      end

      data = {
         'layout'        => 'post',
         'title'         => title.to_s,
         'excerpt'       => post[:post_excerpt].to_s,
         'wordpress_id'  => post[:ID],
         'wordpress_url' => post[:guid],
         'categories'    => categories,
         'tags'          => post_tags
       }.delete_if { |k,v| v.nil? || v == ''}.to_yaml

      File.open("_posts/#{name}", "w") do |f|
        f.puts data
        f.puts "---"
        f.puts content
      end

    end
  end
end