‎‎جسون و اچ تي ام الJSON HTML -‎

const dbParam = JSON.stringify({table:"customers",limit:20});
const xmlhttp = new XMLHttpRequest();
xmlhttp.onload = function() {
  myObj = JSON.parse(this.responseText);
  let text = "<table border='1'>"
  for (let x in myObj) {
    text += "<tr><td>" + myObj[x].name + "</td></tr>";
  }
  text += "</table>"
  document.getElementById("demo").innerHTML = text;
}
xmlhttp.open("POST", "json_demo_html_table.php");
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send("x=" + dbParam);

<select id="myselect" onchange="change_myselect(this.value)">
  <option value="">Choose an option:</option>
  <option value="customers">Customers</option>
  <option value="products">Products</option>
  <option value="suppliers">Suppliers</option>
</select>

<script>
function change_myselect(sel) {
  const dbParam = JSON.stringify({table:sel,limit:20});
  const xmlhttp = new XMLHttpRequest();
  xmlhttp.onload = function() {
    const myObj = JSON.parse(this.responseText);
    let text = "<table border='1'>"
    for (let x in myObj) {
      text += "<tr><td>" + myObj[x].name + "</td></tr>";
    }
    text += "</table>"
    document.getElementById("demo").innerHTML = text;
  }
  xmlhttp.open("POST", "json_demo_html_table.php");
  xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  xmlhttp.send("x=" + dbParam);
}
</script >

const dbParam = JSON.stringify({table:"customers",limit:20});
const xmlhttp = new XMLHttpRequest();
xmlhttp.onload = function() {
  const myObj = JSON.parse(this.responseText);
  let text = "<select>"
  for (let x in myObj) {
    text += "<option>" + myObj[x].name + "</option>";
  }
  text += "</select>"
  document.getElementById("demo").innerHTML = text;
  }
}
xmlhttp.open("POST", "json_demo_html_table.php", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send("x=" + dbParam);

<?php 
$rcode=json_decode( $_POST['x']);
$table_name=$rcode->table; $limit=$rcode->limit; 
 
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "northwind";
//SELECT column_name(s) FROM table_name 
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if  ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
}
//$sql = "SELECT customername as name FROM ". $table_name." limit ". $limit;
switch ($table_name){
	case "customers":
      $sql="SELECT customername as name FROM ". $table_name;
      break; 
    case "products":
      $sql="SELECT productname as name FROM ". $table_name;
      break; 
    case "suppliers":
      $sql="SELECT suppliername as name FROM ". $table_name;
      break;
	default:
      $sql="SELECT customername as name FROM ". $table_name;
}
$sql=$sql." limit $limit";
$result = $conn->query($sql);
echo json_encode($result->fetch_all(MYSQLI_ASSOC));

$conn->close();
?>