Mapping three columns of sql to php arrays - php

Question

I have this MySQL table where I have four columns: location_id, location_name, address, city
I need to make two dropdowns, where the first drop down is the city name. So, if there are 10 cities with all same name, the dropdown should only have 1 city. Upon selecting that city, corresponding location name should come to the next dropdown - location name. Upon selecting the location name dropdown, its corresponding address to be displayed.
One of my logic to do was:
Select all the distinct city from the database. With another query, select all the information.
Query:
SELECT distinct(city) from locations;
This would give me all the different city names.
SELECT * from locations;
All the required data
Make an array, where key will be the city name, and location details as an array. Something like this
Array
(
[0] => stdClass Object
(
[location_id] => 27
[location_name] => ANSND
[address] => some street 1
[city] => NYC
)
[1] => stdClass Object
(
[location_id] => 809
[location_name] => ANBC
[address] => some street 1
[city] => NYC
)
[2] => stdClass Object
(
[location_id] => 810
[location_name] => dasddsdss
[address] => some street 1
[city] => Calif
)
[3] => stdClass Object
(
[location_id] => 811
[location_name] => testing 6 feb
[address] => some street 1
[city] => Calif
)
)
How can I do this in PHP?
Array
(
[NYC] => Array
(
[0] => stdClass Object
(
[location_id] => 27
[location_name] => ANSND
[city] => NYC
[address] => some street 1
)
[1] => stdClass Object
(
[location_id] => 809
[location_name] => ANBC
[city] => NYC
[address] => fsff
)
)
[Calif] => Array
(
[0] => stdClass Object
(
[location_id] => 810
[location_name] => dasddsdss
[city] => Calif
[address] => some street 1
)
[1] => stdClass Object
(
[location_id] => 811
[location_name] => testing 6 feb
[city] => Calif
[address] => some street 1
)
)
)

Answer 1

<?php
$results = array(); // it will be your resulted array
$data_locations = array(); // lets say it is your data list of location table
foreach( $data_locations as $location )
{
$results[$location->city][] = array(
'location_name' =>$location->location_name;
'address' =>$location->address;
)
}
echo "<pre>"; print_r( $results ); die;
?>