I want to make dynamic select options based on database values.
I am getting id when user select an option, I get this id in ajax and then this id is passed in PHP. In PHP I run SQL query based on provided id. Now I want to send response back in AJAX and then I will append my next select option with the given response.
This is my AJAX, from this code I am passing selected_val in PHP. `
    $(document).ready(function() {
        $(".sdpt").change(function(){ 
        let deptid = $(this).val();
        console.log(deptid);
        $.ajax({ 
            method: "POST",
            url: "joins.php",
            data: { selected_val: deptid }, 
            success: function(response){
                console.log(response);
        }
});
    });
});
`
In PHP, I am getting data (pro_name) from database and adding it in an array. I want to return this array in ajax and then I will use it there. Now it is return the whole PHP code in response. Please guide where I am doing mistake and what is the alternative.
`
if (isset($_POST['selected_val']) ) {
    $value = $_POST['selected_val'];
    $myq = new Database();
    $result = $myq->sql("SELECT * FROM programs where dept_id=$value");
    $arr = array();
    while($row = mysqli_fetch_assoc($result)){
        $arr[] = $row['pro_name'];
    };
    echo json_decode("Google");
}
`
