Codeigniter. How to check for duplicates in nested array and update it if duplicates exist?

Question

How to check if nested array contains duplicates? if it does contain duplicate then how to update it?

Example

Array
(

[0] => Array
    (
        [pre_order_id] => 10
        [product_id] => 1
        [product_quantity] => 11
        [product_unit_id] => 2
        [storage_location_id] => 1
        [price] => 1111
    )

    [1] => Array
        (
            [pre_order_id] => 10
            [product_id] => 1
            [product_quantity] => 11
            [product_unit_id] => 2
            [storage_location_id] => 1
            [price] => 1111
        )

    [2] => Array
        (
            [pre_order_id] => 10
            [product_id] => 3
            [product_quantity] => 11
            [product_unit_id] => 2
            [storage_location_id] => 1
            [price] => 1111
        )
)

Here product_id is duplicated on two occasions .i want to keep only one and also update the quantity of it by adding the product_quantity of the other array which will be discarded.

I have tried this

  // $input = array_map("unserialize", array_unique(array_map("serialize", $data_array)));

But it only removes duplicates not update .

Answer 1

After removing duplicates.You have to use $this->db->update_batch() for updating multidimensional array. Like this..

$this->db->update_batch('table_name',$input,$product_id);

For more see Codeigniter Query Builder

Answer 2

If you want to do this in pure PHP you can use something like this:

function cleanDuplicates($aInput) {
    $outPutArray = array();
    foreach($aInput as $element) {
        if(!isset($outPutArray[$element["product_id"]])) {
            $outPutArray[$element["product_id"]] = $element;
        }
        else {
            $outPutArray[$element["product_id"]]["product_quantity"] += $element["product_quantity"];
        }
    }

    return $outPutArray;
}