I want the below sqlquery write using rails joins

sql = "select * from companies c where status = #{Company::ACTIVE} and id in (select company_id from companies_cities cc where cc.city_id=#{city.id}) order by company_name asc"

This is my db structure CREATE TABLE gg.companies ( id int(11) NOT NULL auto_increment, company_name varchar(50) NOT NULL, no_of_employees int(11) NOT NULL, contact_person varchar(100) NOT NULL, status tinyint(1) NOT NULL, created_at date NOT NULL, updated_at date NOT NULL, PRIMARY KEY (id) ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=latin1

CREATE TABLE gg.companies_cities ( id int(11) NOT NULL auto_increment, company_id int(11) NOT NULL, city_id int(11) NOT NULL, created_at datetime default NULL, updated_at datetime default NULL, status tinyint(1) NOT NULL default '1', PRIMARY KEY (id) ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=latin1

CREATE TABLE gg.cities ( id int(11) NOT NULL auto_increment, city_name varchar(40) NOT NULL, status tinyint(1) NOT NULL default '1', created_at datetime NOT NULL, updated_at datetime NOT NULL, PRIMARY KEY (id) ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1"

I want to get the companies based on selected city and companies staus should be active. Can anybody help to write in rails joins EX:Company.find(:all,:joins{etc.....})