Stuck with merging arrays

[frisk]

Hi, I hope someone can help me...

I'm building a stats system for my company and have come to a bit of a halt regarding array merges.

I currently had 2 arrays which i pull out of the database looking like something like this

Array 1

Country_ID Count
GB 698
US 167
NL 2
SE 2
EU 1
LU 1

Array 2

Country_ID Count
GB 4295
US 910
NL 10
EU 5
DE 4
SE 3
FR 3
CA 2

And im trying to write a function that would work like this

$array_output = merge_array($array1, $array2);

Combining both arrays and their values outputting something like

Country_ID Count
GB 4993
US 1077
NL 12
EU 6
SE 5
DE 4
FR 3
CA 2
LU 1

It also needs to work with other arrays but they are always in the same format (i.e. key and numeric value) ...

e.g.

OS_ID Count
NT 5.1 661
WIN 98 62
NT 5 62

or

Provider_ID Count
Google 472
Ask 87
AOL 5

I am completely stuck on how to approach this, at first I thought a simple array_merge or array_merge_recursive would work but all php's array functions either overwrite the values or append them...

I would be eternally grateful if someone could help me out with this, i've been trying to figure it out for days and now i have steam coming out of my ears.

Thanks

[Installer]

Try this:

function array_mix_add($arr_1, $arr_2)
{
    foreach ($arr_1 as $key => $val) {
        if (array_key_exists($key, $arr_2)) {
            $tmp_1[$key] = $val + $arr_2[$key];
        } else {
            $tmp_1[$key] = $val;
        }
    }
    foreach ($arr_2 as $key => $val) {
        if (!array_key_exists($key, $arr_1)) {
            $tmp_2[$key] = $val;
        }
    }
    return array_merge($tmp_1, $tmp_2); 
}

[frisk]

Thanks so much 🙂 I will try this first thing in the morning

[Installer]

Here's a better (much more efficient) one:

function array_mix_add($arr_1, $arr_2)
{
    foreach ($arr_1 as $key => $val) {
        if (array_key_exists($key, $arr_2)) {
            $arr_1[$key] = $val + $arr_2[$key];
            unset($arr_2[$key]);
        }
    }
    return array_merge($arr_1, $arr_2); 
}

[frisk]

Hi Installer, i dont know if i did this wrong but it's still only returning array 1...

Here's an example of the arrays im trying to use.. this is what they look like when i pull them out of the database...

array 1

(
[0] => Array
(
[0] => gb
[country_id] => gb
[1] => 698
[count] => 698
)

[1] => Array
    (
        [0] => us
        [country_id] => us
        [1] => 167
        [count] => 167
    )

[2] => Array
    (
        [0] => nl
        [country_id] => nl
        [1] => 2
        [count] => 2
    )

[3] => Array
    (
        [0] => se
        [country_id] => se
        [1] => 2
        [count] => 2
    )

[4] => Array
    (
        [0] => eu
        [country_id] => eu
        [1] => 1
        [count] => 1
    )

[5] => Array
    (
        [0] => lu
        [country_id] => lu
        [1] => 1
        [count] => 1
    )

)

array 2

Array
(
[0] => Array
(
[0] => gb
[country_id] => gb
[1] => 571
[count] => 571
)

[1] => Array
    (
        [0] => us
        [country_id] => us
        [1] => 128
        [count] => 128
    )

[2] => Array
    (
        [0] => nl
        [country_id] => nl
        [1] => 3
        [count] => 3
    )

[3] => Array
    (
        [0] => eu
        [country_id] => eu
        [1] => 3
        [count] => 3
    )

[4] => Array
    (
        [0] => fr
        [country_id] => fr
        [1] => 2
        [count] => 2
    )

[5] => Array
    (
        [0] => it
        [country_id] => it
        [1] => 1
        [count] => 1
    )

[6] => Array
    (
        [0] => a2
        [country_id] => a2
        [1] => 1
        [count] => 1
    )

[7] => Array
    (
        [0] => cz
        [country_id] => cz
        [1] => 1
        [count] => 1
    )

)

[Weedpacket]

Ah, well, there's your problem then. The assumption going around has been that your array looks like

Array
(
    [GB] => 2997,
    [US] => 167,
    [NL] => 1
[i]etc.[/i]
)

Unless I'm mistaken, if you're getting these rows out of the database, then you might as well do the summing there and retrieve the sums.

Um, "Select country_id, SUM(count) as countfrom your_table group by country_id" I think.

[frisk]

Hi Weedpacket,

I can't do it from the database as this is a stats system and i dont keep the record logs of each individual click.

Each night a script runs which pulls out the daily stats from the record log of each click and writes a new daily record to the database with the daily results arrays serialized into the database...

What im trying to do is if the client wants to see the results from say 11 may to the 13 may, 3 records, 11th, 12th and 13th of may will be pulled out... and then i unserialize the arrays, and then merge them together to give the final result array... and each array, whether its the country array above, or a browser array which shows the daily browser stats are all in the same format as above... except country_id is replaced with browser id...

Any other ideas? I appreciate all your help, thanks

[Weedpacket]

Sounds like a pretty hinky setup (it sounds like you're using a database to store an array that has been serialized as a string and containing data that had been drawn from the database: joy!). But anyway.

Here's a function to get from your array structure to the one I displayed. Then the earlier posts apply.

function fix_an_array($needs_fixing)
{
    $fixed = array();
    foreach($needs_fixing as $element)
    {
        $country_id = $element['country_id'];
        $count = $element['count'];
        $fixed[$country_id] = $count;
    }
    return $fixed;
}

[Installer]

I got this code ready before I saw Weedpacket's, so I'll post it. His will work as well as this, assuming you don't have any more surprises for us:

$array_1 = array_restucture($array_1);
$array_2 = array_restucture($array_2);
$new_arr = array_mix_add($array_1, $array_2);

function array_restructure($arr)
{
    foreach ($arr as $key => $value) {
        $new_arr[$value['country_id']] = $value['count'];
    }
    return $new_arr;
}

function array_mix_add($arr_1, $arr_2)
{
    foreach ($arr_1 as $key => $val) {
        if (array_key_exists($key, $arr_2)) {
            $arr_1[$key] = $val + $arr_2[$key];
            unset($arr_2[$key]);
        }
    }
    return array_merge($arr_1, $arr_2); 
}

[frisk]

Perfect! 🙂 This works! yay!

Thanks so much... i guess i need to get my head around arrays for the future hehe...

Thanks for the help guys