从发帖的角度来看,我是这个论坛的新手,正如这个问题可能表明的那样。我对数据的显示方式有一些疑问。
所以,我有 3 个表(我只显示我想要的列):
访客:
center_id (where the visitor was) | state_id (where they came from)
中心:
center_id | center
状态:
state_id | state
这是我一直在使用的查询
SELECT states.state, visitors.center_id, visitors.state_id, centers.center, COUNT(visitors.state_id) AS totalCount
FROM visitors
LEFT JOIN states ON states.state_id = visitors.state_id
LEFT JOIN centers ON centers.center_id = visitors.center_id
WHERE visitors.vdate = <some date> AND visitors.state_id <> '0'
GROUP BY centers.center, visitors.state_id
这会产生以下数组:
Array
(
[0] => Array
(
[state] => Connecticut
[location_id] => 1
[state_id] => 8
[center] => Little River
[totalCount] => 1
)
[1] => Array
(
[state] => California
[location_id] => 5
[state_id] => 6
[center] => North Augusta
[totalCount] => 1
)
[2] => Array
(
[state] => Colorado
[location_id] => 5
[state_id] => 7
[center] => North Augusta
[totalCount] => 2
)
[6] => Array
(
[state] => Connecticut
[location_id] => 9
[state_id] => 8
[center] => Santee
[totalCount] => 2
)
[7] => Array
(
[state] => Virginia
[location_id] => 9
[state_id] => 51
[center] => Santee
[totalCount] => 1
)
)
这才是我真正想要的:
Array
(
[Little River] => Array
(
[0] => Array
(
[state] => Connecticut
[state_id] => 8
[totalCount] => 1
)
)
[North Augusta] => Array
(
[0] => Array
(
[state] => California
[state_id] => 6
[totalCount] => 1
)
[1] => Array
(
[state] => Colorado
[state_id] => 7
[totalCount] => 2
)
)
[Santee] => Array
(
[0] => Array
(
[state] => Connecticut
[state_id] => 8
[totalCount] => 2
)
[1] => Array
(
[state] => Virginia
[state_id] => 51
[totalCount] => 1
)
)
)
最终我将它放入一个看起来像这样的表中:
__________________
|State | Count|
-------------------
| Santee |
-------------------
| Georgia | 5 |
-------------------
| Alabama | 10 |
-------------------
| North Augusta |
-------------------
| another | 7 |
-------------------
抱歉啰嗦,但这是我能描述的唯一方式。
我也试过用 php 来破解它,但我也可能在那里做错了什么。我可以制作一个包含 3 列的表格,其中列出每个州的中心,但我真的在寻找一行显示中心,然后是所有州和该中心以及下一个中心的计数。
如有任何帮助,我们将不胜感激。
最佳答案
查询可能只返回二维(或更少)维度的结果。您将需要解析此结果集以将其转换为树。
用PHP,真的没有难度:
foreach ($rawResultSet as $row) {
$finalResult[$row['center']][] = array(
$row['state'],
$row['state_id'],
$row['totalCount']
);
}
关于mysql加入和分组,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17119921/