我有桌子:
+------+-------+-----------------+
| id | name | code | desc |
+------+-------+-----------------+
| 1 | aa | 032016 | grape |
| 1 | aa | 012016 | apple |
| 1 | aa | 032016 | grape |
| 1 | aa | 022016 | orange |
| 1 | aa | 012016 | apple |
| 1 | aa | 032016 | grape |
+------+-------+-----------------+
我试过查询:
SELECT id, name, code, desc, COUNT(code) as view
FROM mytable
GROUP BY id, name, code, desc
结果是:
+------+-------+------------------------+
| id | name | code | desc | view |
+------+-------+------------------------+
| 1 | aa | 012016 | apple | 2 |
| 1 | aa | 022016 | orange | 1 |
| 1 | aa | 032016 | grape | 3 |
+------+-------+------------------------+
我的期望是这样的:
+------+-------+----------------------------------------------------+
| id | name | code | desc | view |
+------+-------+----------------------------------------------------+
| 1 | aa | 012016,022016,032016 | apple,orange,grape | 2,1,3 |
+------+-------+----------------------------------------------------+
任何人都可以帮我如何汇总结果吗? 提前谢谢
答案 0 :(得分:2)
你的桌面设计让我有点担心。一个水果在表中总是有相同的代码是巧合吗?那为什么要冗余存储呢?应该有一个水果桌,每个水果及其代码只有一次。你知道为什么这被称为关系数据库系统,不是吗?
但是,根据您的查询,您几乎可以获得所需内容。您有每个ID,名称,代码和desc的计数。现在你想进一步聚合。所以在下一步中按ID和名称分组,因为你想要每个id和名称一个结果行。使用LISTAGG
连接组中的字符串:
SELECT
id,
name,
listagg(code, ',') within group(order by code) as codes,
listagg(desc, ',') within group(order by code) as descs,
listagg(view, ',') within group(order by code) as views
FROM
(
SELECT id, name, code, desc, COUNT(*) as view
FROM mytable
GROUP BY id, name, code, desc
)
GROUP BY id, name
ORDER BY id, name;