tp3.2多表联查的几种形式

$q1 = "'%$q1%'";
$goods = M("goods");
$goodslist = $goods
    ->alias("g")
    ->join("shopping_goodsimg i on g.id = i.goods_id")
    ->where("i.is_main=1 and g.is_show=1 AND g.name like $q1")
    ->field(array("g.id", "g.name", "g.price", "g.num", "g.sales_num", "g.is_show", "g.is_new", "g.is_hot","g.is_integral", "g.is_coupon", "g.special_id", "g.seckill_id", "g.integral_price","g.category_id", "i.img"))
    ->select();

$Model = new \Think\Model();
$list = $Model->table('shopping_coupon AS c,shopping_user_coupon AS uc')->where('c.id = uc.coupon_id')->select();