Convert JSON to array in MySQL column using Laravel

I have a column that stores a data in JSON format in MySQL table in form of

a:3:{s:2:"12";s:0:"";s:2:"34";s:0:"";s:2:"56";s:10:"1234567890";}

But since $cast was introduced in Laravel 5, I was planing to reformat my data and code to use with array casting.

Didn't find a direct conversion tips, so tried this:

1. Created a column with same attributes (colB) as in the original column (colA).
2. Inserted this in my model protected $casts = ['colA' => 'json', 'colB' => 'array'];
3. Executed this code:

---

foreach(Model::all() as $item){
   $item->colB = $item->colA;
   $item->save();
}

Code executed w/o errors, but nothing happened. colB was empty. Than I though maybe Laravel doesn't like my JSON formatting, so I change the code to this:

foreach(Model::all() as $item){
   $item->colB = unserialize($item->colA);
   $item->save();
}

And protected $casts = ['colB' => 'array'];

But I got unserialize() expects parameter 1 to be string error, even though if I dd($item->colA) I get a perfect string. And, which is more amazing, if I dd(unserialize($item->colA)) I get a perfect array.

I though maybe my data is causing this, and tried doing that with a table which had a single row to no avail.

Any tips appreciated!

via Chebli Mohamed