MySQL：重复条目拉动

Question

当我拉下MySQL代码时：

SELECT distinct *
FROM product_size AS ps 
INNER JOIN product_type AS pt ON ps.product_id = pt.product_id
WHERE product_type = 'Business Card' 
;

提取以下图片：

我要做的是确保当我们从我们的网站上提取它时，它只在我们的页面上拉出一个大小的实例。

所以基本上，当我们在我们的网站上进行选择时，我希望它能够拉大小。

当我在我们的网站上提取它时，会出现以下内容：

http://screencast.com/t/eowXtDol6IOZ

Answer 1

我假设您的product_id是唯一的，因此请使用product_id而不是所有记录。

SELECT distinct ps.product_id, ps.*
FROM product_size AS ps 
INNER JOIN product_type AS pt ON ps.product_id = pt.product_id
WHERE product_type = 'Business Card' ;

Answer 2

你可以像这样轻松删除不必要的物品

SELECT DISTINCT size, produce_type, p_dimension
FROM 
(SELECT distinct *
FROM product_size AS ps 
INNER JOIN product_type AS pt ON ps.product_id = pt.product_id
WHERE product_type = 'Business Card')

或

SELECT DISTINCT rs.size, rs.produce_type, rs.p_dimension
FROM 
(SELECT distinct *
FROM product_size AS ps 
INNER JOIN product_type AS pt ON ps.product_id = pt.product_id
WHERE product_type = 'Business Card') rs