a_query.rb

###
# lolquery is an fresh new take on SQL DSLs.  NEVER WRITE SQL AGAIN!  Using
# amazing lolquery technology, you too will never have to write another SQL
# statement again!
#
# Check out this simple example of using lolquery.  Bask in it's simplicity,
# it's expressiveness, but most importantly, it's lack of writing SQL!
#
# <3 <3 <3 <3 <3

require 'lolquery'

x = SELECT * FROM("users") .WHERE(:id => 10)
puts x # => SELECT * FROM "users" WHERE "users"."id" = 10

lolquery.rb

require 'rubygems'
require 'arel'
require 'fake_record' # stub out AR (stolen from arel tests)

class Select < Struct.new(:columns)
  def self.* other
    other.select = new(Arel.sql('*'))
    other
  end
end

class From < Struct.new(:table, :conditions)
  def WHERE conditions
    self.conditions = conditions
    Where.new(self)
  end
end

class Where < Struct.new(:from, :select)
  def to_s
    Arel::Table.engine = Arel::Sql::Engine.new(FakeRecord::Base.new)
    table = Arel::Table.new from.table
    table.project(select.columns).where(
      from.conditions.map { |k,v| table[k].eq v }).to_sql
  end
end

SELECT = Select
def FROM table
  From.new table
end

the_fake_record.rb

module FakeRecord
  class Column < Struct.new(:name, :type)
  end

  class Connection
    attr_reader :tables

    def initialize
      @tables = %w{ users photos developers }
      @columns = {
        'users' => [
          Column.new('id', :integer),
          Column.new('name', :string),
          Column.new('bool', :boolean),
          Column.new('created_at', :date),
        ]
      }
      @primary_keys = {
        'users' => 'id'
      }
    end

    def primary_key name
      @primary_keys[name.to_s]
    end

    def table_exists? name
      @tables.include? name.to_s
    end

    def columns name, message = nil
      @columns[name.to_s]
    end

    def quote_table_name name
      "\"#{name.to_s}\""
    end

    def quote_column_name name
      "\"#{name.to_s}\""
    end

    def quote thing, column = nil
      if column && column.type == :integer
        return 'NULL' if thing.nil?
        return thing.to_i
      end

      case thing
      when true
        "'t'"
      when false
        "'f'"
      when nil
        'NULL'
      when Numeric
        thing
      else
        "'#{thing}'"
      end
    end
  end

  class ConnectionPool
    class Spec < Struct.new(:config)
    end

    attr_reader :spec, :connection

    def initialize
      @spec = Spec.new(:adapter => 'america')
      @connection = Connection.new
    end

    def with_connection
      yield connection
    end
  end

  class Base
    attr_accessor :connection_pool

    def initialize
      @connection_pool = ConnectionPool.new
    end

    def connection
      connection_pool.connection
    end
  end
end