In a DB table from wordpress (Caldera Form plugin), there's a JSON array as value, and from a query, result has this structure :

```
Array (
    [0] => stdClass Object (
        [config] => a:22:{
            s:2:"ID";
            s:15:"CF605df92fa7a17";
            s:13:"_last_updated";
            s:31:"Sat, 27 Mar 2021 16:44:15 +0000";
            s:10:"cf_version";
            s:5:"1.9.4";
            s:4:"name";
            s:29:"Registration for Artists 2021";
            s:10:"scroll_top";...}
        ) 
    [1] => stdClass Object (
        [config] => a:22:{
            s:2:"ID";
            s:15:"CF605ba79300239";
            s:13:"_last_updated";
            s:31:"Sat, 27 Mar 2021 16:44:51 +0000";
            s:10:"cf_version";
            s:5:"1.9.4";
            s:4:"name";
            s:29:"Inscription des Artistes 2021";
            s:10:"scroll_top";...}
        ) 

```

How can i read "a:22" then "s:15" inside ?
I done a json\_decode with [config] value but it return a empty value..