我需要通过更改显示的表上的值来更新数据库

Question

每次更改选择输入时，我都试图更新数据库。我需要类似onchange之类的东西，此外，我还必须考虑该行的ID。有人可以帮助我吗？

我必须说我有一张包含更多信息的表，但我只是在问我需要更改的内容。

<?php
    class conexion{
            function recuperarDatos2(){
                $host = "localhost";
                $user = "root";
                $pw = "xxxxxx";
                $db = "almacen";

                $con = mysql_connect ($host, $user, $pw) or die ("No se puedo conectar a la base de datos ");
                mysql_select_db($db, $con) or die ("No se encontró lo que buscaba ");
                $query = "SELECT * FROM pedidos ORDER BY ID ASC" ;

                $resultado = mysql_query($query);
                $numero = mysql_num_rows($resultado); 
                mysql_set_charset('utf8');


while ($fila = mysql_fetch_array($resultado)) {

echo "<tr>";
echo "

<input type='hidden' value=' $fila[ID] '>

<td> 
 <input id='ancho-series' type='text' class='form-control-sm' name='serie' placeholder=' $fila[serie] '> 
// I should be able to write on this field and update the database
</td>

<td class='los_operarios'>
 <select class='operarios' name='operario' >
 </select>   
// I should be able to change the value of this select and update the database
 <span class='ope'> $fila[operario] </span> 
//this is showing the $fila[operario] with a different color 
</td>

<td class='mis_estados'>
 <select id='ancho' class='estados' name='estado' >
 </select>
 // I should be able to change the value of this select and update the database
 <span class='podemos'> $fila[estado]  
 </span>
//this is only showing the $fila[estado] with a different color 
</td>


";
echo "</tr>";
  }
 }
}

?>