在mysql查询中具有独立列的组

Question

我试图将查询的结果分组并显示在单独的列中。

表名：category_results

+---------+-----------------+ 
| cat_id | Total   | 
+---------+-----------------+ 
| CA001 |   150.00 | 
| CA002 |   130.00 | 
| CA002 |   200.00 | 
| CA003 |   70.00 | 
| CA001 |   75.00 | 
+---------+-----------------+ 

我想这样的结果：

+--------+--------+--------+ 
| CA001 | CA002 | CA003 | 
+--------+--------+--------+ 
| 255.00 | 330.00 | 70.00 | 
+--------+--------+--------+ 

任何想法？

Answer 1

您可以使用SUM与CASE WHEN相结合，实现你想要什么：

SELECT SUM(t.CA001) AS CA001, 
     SUM(t.CA002) AS CA002, 
     SUM(t.CA003) AS CA003 
FROM 
(
    SELECT CASE WHEN cat_id = 'CA001' THEN Total ELSE 0 END AS CA001, 
      CASE WHEN cat_id = 'CA002' THEN Total ELSE 0 END AS CA002, 
      CASE WHEN cat_id = 'CA003' THEN Total ELSE 0 END AS CA003 
    FROM category_results 
) t 

点击下面的链接，运行演示。

SQLFiddle