我需要添加条件或函数来从数据库获取新数据后更改图片 - I need to add condition or function to change picture after get a new data from database

I need to add condition or function to change picture after get a new data from database

从数据库接收新数据后，我想使用 val["id"] make 条件来更改图片。第一个脚本是从数据库中获取新数据的脚本，第二个是我想这样做但没有成功的条件示例。

function getDataFromDb() {
    $.ajax({
        //SELECT * FROM my_db WHERE 1 ORDER BY id DESC limit 1 (Get only newest data from database.)
        url: "getData.php",
        type: "POST",
        data: ''
    }).success(function(result) {
        var obj = jQuery.parseJSON(result);
        if (obj != '') {
          //$("#myTable tbody tr:not(:first-child)").remove();
          $("#myBody").empty();
          $.each(obj, function(key, val) {
            var tr = "<tr>";
            tr = tr + "<td>" + val["id"] + "</td>";
            tr = tr + "<td>" + val["first_name"] + "</td>";
            tr = tr + "<td>" + val["last_name"] + "</td>";
            tr = tr + "<td>" + val["age"] + "</td>";
            tr = tr + "<td>" + val["hometown"] + "</td>";
            tr = tr + "<td>" + val["job"] + "</td>";
            tr = tr + "</tr>";
            $('#myTable > tbody:last').append(tr);
          });
        }
    });
}
  //get new data from database every 10 second
setInterval(getDataFromDb, 10000); // 1000 = 1 second

ex. if(val["id"] > 10){
         //Change picture to 1.jpg
        } elseif(val["id"] > 20){
         //Change picture to 2.jpg
        }  else {
         //Change picture to 3.jpg
        };

这是一个我想得到它的例子，但我不知道所有的语法来完成它

//谢谢

似乎您的 ajax 调用缺少id值...

$.ajax({
        //SELECT * FROM my_db WHERE 1 ORDER BY id DESC limit 1 (Get only newest data from database.)
        url: "getData.php",
        type: "POST",
        data: {id: 'YOUR-ID-GOES-HERE'}
    }
    .....