docs: function postGetTags(id, cb) {
    var q  =
      'SELECT * FROM tags t ' +
        'JOIN posts_tags pt ON t.id = pt.tag_id AND pt.post_id = $1';
  
    db.getClient(function(err, client, done) {
      client.query(q, [id], function(err, r) {
        if(err) {
          cb(err);
          done(err);
        } else {
          cb(null, r.rows);
          done();
        }
      });
    });
  }