mysql - 左连接导致重复行

Question

我有一个查询成功地从我的产品表中获取独特的产品并显示它们。我正在尝试将图标表添加到组合中，其中某些产品可以有多个图标。问题是我试图只使用连接，例如，当一个产品有 2 个图标时，我将为该 1 个产品选择 2 行。

这是我的sql：

    SELECT p.products_image, 
           pd.products_name, 
           p.products_id, 
           p.products_model, 
           p.manufacturers_id, 
           p.products_price, 
           p2i.icons_id, 
           p.products_tax_class_id, 
           IF(s.status, s.specials_new_products_price, NULL)             AS 
           specials_new_products_price, 
           IF(s.status, s.specials_new_products_price, p.products_price) AS 
           final_price 
    FROM   products p 
           LEFT JOIN manufacturers m 
                  ON p.manufacturers_id = m.manufacturers_id 
           LEFT JOIN specials s 
                  ON p.products_id = s.products_id 
           LEFT JOIN products_to_categories p2c 
                  ON p.products_id = p2c.products_id 
           LEFT JOIN products_description pd 
                  ON p.products_id = pd.products_id 
           LEFT JOIN products_to_icon p2i 
                  ON p.products_id = p2i.products_id 
    WHERE  p.products_status = '1' 
           AND pd.language_id = '1' 
           AND p2c.categories_id = '36'

Answer 1

GROUP BY在末尾添加一个子句。如果你仍然想要所有的图标 id，你可以结合group_concat

例如：

SELECT p.products_image, 
       pd.products_name, 
       p.products_id, 
       group_concat(p2i.icons_id separator ",") as icons_ids
       (...)
WHERE  p.products_status = '1' 
       AND pd.language_id = '1' 
       AND p2c.categories_id = '36'
GROUP BY p.products_id