Cannot get value of implode() response from php file using ajax (array to string conversion error)

The scenario is here I accept all button click that has ID starts with 'editbtn' like editbtn1/editbtn2 etc ; and get only the number to send via ajax to find data id based on the button id (number)

    $(document).ready(function(){
        $('[id^=editbtn]').click( function () {
            noform=this.id.match(/\d+/);
            event.preventDefault();
        
            $.ajax({
                'url': 'visitor_book_crud.php',
                'data': {
                    'request': 'find_data',
                    'data_id': noform
                },
                'type': 'post',
                'dataType': 'html',
                'beforeSend': function () { }
            })
            .done( function (response) {
                console.log(response);
            })
            .fail( function (code, status) {    alert(code+' - '+status);
            })
            .always( function (xhr, status) {   })
        });
    });

And In visitor_book_crud.php

    if ($request=="find_data"){
        $data_id = $_REQUEST['data_id'];

        $mqdata = mysql_query("SELECT * FROM tb_visitorbook WHERE id_vb = '$data_id'") or die (mysql_error());
        $mfadata = mysql_fetch_assoc($mqdata);
        if($mfadata){
            echo implode(",", $mfadata);
        } else {
            echo "failed"; 
        }
    }

I tried to directly send request to visitor_book.crud?request=find_data&data_id=1 and the output is like this, exactly same as what I want to be appeared in ajax response 1,2022-06-29,03:07:30,03:39:39,6,,A_NAME,3,,,SOME_NAME,,1,

But when I press edit button, it says

<br />
<b>Notice</b>:  Array to string conversion in <b>C:\xampp\htdocs\security_editless\visitor_book_crud.php</b> on line <b>48</b><br /> //line 48 is in mysql_query("SELECT......
failed

I searched from many thread but still dont solve my problem, any help would be appreciated