问题描述
我有这组示例数据：
表invoice：
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| ID | date | invoice_number | total |
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| 81 | 2017-03-24 | 0000000173 | 190.00 |
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表invoice_addon：
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| ID | invoice_id | description | amount |
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| 46 | 81 | Price Adjust. - Jumbo | -12.00 |
| 47 | 81 | Price Adjust. - Regular | -12.00 |
----------------------------------------------------------
表orders：
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| ID | invoice_id | Box_name | size | price | tax | Box_number |
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| 177 | 81 | Jumbo Box | 23x25x17 | 97.00 | 15.00 | FCI107056 |
| 178 | 81 | Regular Box | 20x23x17 | 87.00 | 15.00 | FCI107057 |
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我想要实现的目标：
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| trans_date | inv_number | Box_name | size | gross | Box_number | others | description | net |
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| 2017-03-24 | 0000000173 | Jumbo Box | 23x25x17 | 112.00 | FCI107056 | -24.00 | Price Adjust. - Jumbo -12.00 | 88.00 |
| | | | | | | | Price Adjust. - Regular -12.00 | |
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| 2017-03-24 | 0000000173 | Regular Box | 20x23x17 | 102.00 | FCI107057 | 0 | NULL | 102.00|
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我当前的查询：
SELECT DATE(i.date) AS trans_date,i.invoice_number AS inv_number,o.Box_name as Box_name,o.size AS size,(SELECT Price + Tax FROM orders WHERE ID = o.ID) AS gross,o.Box_number AS Box_number,SUM(a.amount) AS others,(SELECT GROUP_CONCAT(CONCAT(description,' ',amount) SEParaTOR '<br />') FROM invoice_addon WHERE invoice_id = i.ID) AS description,(SUM(o.price + o.tax) + SUM(a.amount)) AS net
FROM `invoice` i
INNER JOIN orders o ON i.ID = o.invoice_id
LEFT JOIN invoice_addon a ON i.ID = a.invoice_id
WHERE i.ID = 81
GROUP BY o.ID
我的查询结果中的问题是others和description列已加倍。它只能显示在第一行。不管发票中捆绑了多少盒，都应仅在第一行中添加它们。网络也依赖于这些列。
我得到的是
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| trans_date | inv_number | Box_name | size | gross | Box_number | others | description | net |
----------------------------------------------------------------------------------------------------------------------------------
| 2017-03-24 | 0000000173 | Jumbo Box | 23x25x17 | 112.00 | FCI107056 | -24.00 | Price Adjust. - Jumbo -12.00 | 200.00 |
| | | | | | | | Price Adjust. - Regular -12.00 | |
----------------------------------------------------------------------------------------------------------------------------------
| 2017-03-24 | 0000000173 | Regular Box | 20x23x17 | 102.00 | FCI107057 | -24.00 | Price Adjust. - Jumbo -12.00 | 180.00 |
| | | | | | | | Price Adjust. - Regular -12.00 | |
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有可能吗？我该怎么做？ （我正在使用CodeIgniter和DataTable在MysqL中进行此操作）
解决方法
好吧，您需要一些var来存储当前行号并检查其是否等于1。像这样：
SET @row_number = 0;
SELECT DATE(i.date) AS trans_date,i.invoice_number AS inv_number,o.box_name as box_name,o.size AS size,(SELECT Price + Tax FROM orders WHERE ID = o.ID) AS gross,o.box_number AS box_number,if((@row_number:=@row_number + 1)=1,SUM(a.amount),null) AS others,if(@row_number=1,(SELECT GROUP_CONCAT(CONCAT(description,' ',amount)
SEPARATOR '<br />') FROM invoice_addon WHERE invoice_id = i.ID),null) AS description,(SUM(o.price + o.tax) + SUM(a.amount)) AS net
FROM `invoice` i
INNER JOIN orders o ON i.ID = o.invoice_id
LEFT JOIN invoice_addon a ON i.ID = a.invoice_id
WHERE i.ID = 81
GROUP BY o.ID