How to format an associative array with another structure? - php

Question

I have a query like this:
select truck, oil_type, km_min, km_max from trucks;
I'm using codeigniter and with the $query->result_array() function so its loaded in an associative array with this structure:
/*
array(
truck
oil_type
km_min
km_max
)
*/
$arr[0]["truck"] = 2;
$arr[0]["oil_type"] = 2;
$arr[0]["km_min"] = 345;
$arr[0]["km_max"] = 567;
$arr[1]["truck"] = 2;
$arr[1]["oil_type"] = 4;
$arr[1]["km_min"] = 234;
$arr[1]["km_max"] = 867;
$arr[2]["truck"] = 1;
$arr[2]["oil_type"] = 2;
$arr[2]["km_min"] = 545;
$arr[2]["km_max"] = 867;
$arr[3]["truck"] = 4;
$arr[3]["oil_type"] = 3;
$arr[3]["km_min"] = 45;
$arr[3]["km_max"] = 567;
Then, I'm trying to restructure it grouping the trucks by the id, something like this:
/*
trucks - array(
truck
truck_data - array(
oil_type
km_min
km_max
)
)
*/
$arr["truck"][0]= 2;
$arr["truck"][0]["truck_data"][0]["oil_type"] = 2;
$arr["truck"][0]["truck_data"][0]["km_min"] = 345;
$arr["truck"][0]["truck_data"][0]["km_max"] = 567;
$arr["truck"][0]["truck_data"][1]["oil_type"] = 4;
$arr["truck"][0]["truck_data"][1]["km_min"] = 234;
$arr["truck"][0]["truck_data"][1]["km_max"] = 867;
$arr["truck"][1]= 1;
$arr["truck"][1]["truck_data"][0]["oil_type"] = 2;
$arr["truck"][1]["truck_data"][0]["km_min"] = 545;
$arr["truck"][1]["truck_data"][0]["km_max"] = 867;
$arr["truck"][2]= 4;
$arr["truck"][2]["truck_data"][0]["oil_type"] = 3;
$arr["truck"][2]["truck_data"][0]["km_min"] = 45;
$arr["truck"][2]["truck_data"][0]["km_max"] = 567;
I thought in something like the code below:
$res = $query->result_array();
$cnt_total = count($res);
$y = 0;
for ($x=0; $x < $cnt_total -1 ; $x++) {
$truck = $res[$x]["truck"];
$trucks["truck"][$y] = $truck;
$q = $x + 1;
$i = 0;
do{
$trucks[$y][$i]["oil_type"] = $res[$q]["oil_type"];
$trucks[$y][$i]["km_min"] = $res[$q]["km_max"];
$trucks[$y][$i]["km_max"] = $res[$q]["km_max"];
$q++;
$i++;
if ($q <= $cnt_total) break;
} while ( $truck === $res["truck"][$q] );
$y++;
}
But does not work properly... I'm too far of the solution? The performance It's important for me in this particular case.
There is a phpfiddle where you can try:
http://phpfiddle.org/main/code/67j-ui5
Any idea, tip, or advice will be appreciated, and if you need more info, let me know and I'll edit the post.

Answer 1

Try this:
$res = $query->result_array();
$trucks = array();
foreach ($res as $row) {
$truck["truck"] = $row["truck"];
$truck["truck_data"] = array(
'oil_type' => $row["oil_type"],
'km_min' => $row["km_min"],
'km_max' => $row["km_max"],
);
$trucks[] = $truck;
}
var_dump($trucks);

Answer 2

What you've provided as a desired result is a little ambiguous. This might give what you're asking for.
$trucks=array();
$res = $query->result_array(); // assuming this is actually several trucks
foreach ($res as $r){
// set up the array from the data without writing out every column manually
$truck=array(
'truck'=>$r['truck'],
'truck_data'=>$r,
);
// remove the bit you wanted separately as 'truck' from 'truck_data'
unset($truck['truck_data']['truck']);
// push into $trucks
$trucks[]=$truck;
}

Answer 3

Is this what you need? conversion result is stored in $result
$result = array();
foreach($query->result_array() as $truck)
{
$new_truck = array();
$new_truck['truck'] = $truck['truck'];
$new_truck['truck_data'] = array();
$new_truck['truck_data']['oil_type'] = $truck['oil_type'];
$new_truck['truck_data']['km_min'] = $truck['km_min'];
$new_truck['truck_data']['km_max'] = $truck['km_max'];
array_push($result, $new_truck);
}