无法删除php中的数据库(mysql)记录,哪里出错了?

我正在尝试删除MySQL中用户表中的记录,

代码是这样的。

if(isset($_GET['id'])) {
    //create query to delete the record
    $query = "DELETE FROM users WHERE id =" . int($_GET['id'])  or die(mysql_error());

    //execute query
    if($mysqli->query($query)) {
        //print number of affected rows
        echo $mysqli->affected_rows. " row(s) affected";
    }
    else {
        //print error message
        echo "Error in query : $query " . $mysqli->error;
    }
}
else {
    echo "Could not Execute the Delete query";
}

同时,我正在迭代数据库中用户表中的记录,结果是这样的。

//query to get records
$query = "SELECT * FROM users";
//execute query
if($result = $mysqli->query($query)) {
    // see if any rows were returned
    if($result->num_rows > 0) {
        // if yes then print one after another
        echo "<table cellpadding=10 border=1>";
        while($row = $result->fetch_array()) {
            echo "<tr>";
            echo "<td>" .$row[0] . "</td>";
            echo "<td>" .$row[1] . "</td>";
            echo "<td>" .$row[2] . "</td>";
            echo "<td><a href =" . $_SERVER['PHP_SELF']. "?id" .$row[0]. ">Delete</a></td>";
            echo "</tr>";
        }
        echo "</table>";
    }
    $result->close();
}

问题是,我可以从数据库中获取记录并将其显示在浏览器中,但当我尝试删除记录时,第一个条件不通过,即如果(isset($\u get['id'])改为其他条件并打印消息“无法执行删除查询”,我猜它无法获取$\u get['id'],因此只有它引用用于输入if条件,

P.S:如果有人用简单的话解释我,我会很感激的,我是编程新手,谢谢。