$sql = 'SELECT g.goods_id, g.goods_name,g.goods_sn,g.goods_weight, g.goods_name_style, g.et_price, g.is_new, g.is_best, g.is_hot, g.shop_price AS org_price, ' .
"IFNULL(mp.user_price, g.shop_price * '$_SESSION[discount]') AS shop_price, g.promote_price, g.goods_type, " .
'g.promote_start_date, g.promote_end_date, g.goods_brief, g.goods_thumb ,s.attr_value, g.goods_img ' .
'FROM ' . $GLOBALS['ecs']->table('goods') . ' AS g ' .
'LEFT JOIN ' . $GLOBALS['ecs']->table('member_price') . ' AS mp ' .
"ON mp.goods_id = g.goods_id AND mp.user_rank = '$_SESSION[user_rank]' " .
'LEFT JOIN '. $GLOBALS['ecs']->table('goods_attr') . ' AS s' .
"ON s.goods_id = mp.goods_id" .
"WHERE $where $ext ORDER BY $sort $order";这条语句有'goods''member_price''goods_attr'三个表 怎么连接起来
"IFNULL(mp.user_price, g.shop_price * '$_SESSION[discount]') AS shop_price, g.promote_price, g.goods_type, " .
'g.promote_start_date, g.promote_end_date, g.goods_brief, g.goods_thumb ,s.attr_value, g.goods_img ' .
'FROM ' . $GLOBALS['ecs']->table('goods') . ' AS g ' .
'LEFT JOIN ' . $GLOBALS['ecs']->table('member_price') . ' AS mp ' .
"ON mp.goods_id = g.goods_id AND mp.user_rank = '$_SESSION[user_rank]' " .
'LEFT JOIN '. $GLOBALS['ecs']->table('goods_attr') . ' AS s' .
"ON s.goods_id = mp.goods_id" .
"WHERE $where $ext ORDER BY $sort $order";这条语句有'goods''member_price''goods_attr'三个表 怎么连接起来
right join
inner join
……