mysql joins and groups - mysql

Question

I'm new to this forum from the standpoint of posting, as this question may show. I'm having some issues with the way I want my data to appear.
So, I have 3 tables (I am only showing the columns that I want):
visitors:
center_id (where the visitor was) | state_id (where they came from)
centers:
center_id | center
states:
state_id | state
here is the query that I have been using
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
This produces the following array:
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
)
)
This is what I really want:
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
)
)
)
Ultimately I'm putting this into a table that looks something like this:
__________________
|State | Count|
-------------------
| Santee |
-------------------
| Georgia | 5 |
-------------------
| Alabama | 10 |
-------------------
| North Augusta |
-------------------
| another | 7 |
-------------------
Sorry for being long winded, but this was the only way that I could describe it.
I've also tried breaking it out in php, but I'm probably doing something wrong there too. I can make a table with 3 columns with the center listed with each state, but I'm realliy looking for a row that show the center followed by all of the states and counts for that center and on to the next center.
Any assistance would be appreciated.

Answer 1

A query may only return a two- (or less) dimentional result. You will need to parse this result set to transform it into a tree.
With PHP, there really is no difficulty:
foreach ($rawResultSet as $row) {
$finalResult[$row['center']][] = array(
$row['state'],
$row['state_id'],
$row['totalCount']
);
}