在连接来自不同表的值时使用GROUP_CONCAT和CONCAT

Question

我有以下查询来提取订单的所有订单：

SELECT 
   order_id, 
   GROUP_CONCAT(order_item_name SEPARATOR ' | ') as 'items' 
FROM 
   wp_woocommerce_order_items oi1 
WHERE 
   oi1.order_item_type = 'line_item' 
   AND order_id = 422 
GROUP BY
   order_id

它返回我想要的结果：

我现在要做的是从另一个表中添加如下所示的数据：

SELECT * FROM wp_woocommerce_order_itemmeta where order_item_id = 17

wp_woocommerce_order_itemmeta和wp_woocommerce_order_items加入order_item_id

所以我最终的期望结果看起来像是：

order_item_name:_qty:_line_subtotal

order_id | items
--------- -----------------------------------
422      | Metal Polish:1:13.09 

Answer 1

你需要这样的吗？

SELECT * FROM wp_woocommerce_order_itemmeta as wc 
inner join
(SELECT 
   order_id, 
   GROUP_CONCAT(order_item_name SEPARATOR ' | ') as 'items' 
FROM 
   wp_woocommerce_order_items oi1 
WHERE 
   oi1.order_item_type = 'line_item' 
   AND order_id = 422 
GROUP BY
   order_id) as order_counts
using (order_id)

Answer 2

以下是仅使用一个LEFT JOIN和一个CONCAT

的示例

SELECT 
   oi1.order_id, 
   GROUP_CONCAT( 
     CONCAT(oi1.order_item_name , ':', ii.meta_value)
     SEPARATOR ' | ') as 'items' 
FROM 
   wp_woocommerce_order_items oi1 
LEFT JOIN
    wp_woocommerce_order_itemmeta i ON i.order_item_id = oi1.order_item_id AND i.meta_key= '_line_subtotal'
WHERE 
   oi1.order_item_type = 'line_item' 
   AND oi1.order_id = 422 
GROUP BY
   oi1.order_id;

Answer 3

由于wp_woocommerce_order_itemmeta中的每个值都在自己的行中，因此您需要多次加入该表。

SELECT order_id, GROUP_CONCAT(
   order_item_name,':',qty.meta_value,':',subtotal.meta_value SEPARATOR ' | '
) as 'items' 

FROM wp_woocommerce_order_items oi1

JOIN wp_woocommerce_order_itemmeta qty ON
    qty.order_item_id = oli.order_item_id
    AND qty.meta_key = '_qty'
JOIN wp_woocommerce_order_itemmeta subtotal ON
    qty.order_item_id = oli.order_item_id
    AND qty.meta_key = '_line_subtotal'

WHERE oi1.order_item_type = 'line_item' 
   AND order_id = 422 
GROUP BY order_id