帮忙看一条SQL语句了语句!
以下为zen cart 开源商城系统一条SQL语句!
select distinct p.products_id, p.products_image, p.products_tax_class_id, pd.products_name,
p.products_date_added, p.products_price, p.products_type, p.master_categories_id
from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd
where p.products_id = pd.products_id
and pd.language_id = '" . (int)$_SESSION['languages_id'] . "'
and p.products_status = 1 " . $display_limit;
上面的SQL语句中“p”和“pd”都应该是别名!
但是【from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd】这句在定义别名时没有用到As是怎么回事?它是不是别名?还有其他什么可能的用法没?求大神指点!