Util.php 

<?php

function print_table($data, $headers) {
  # print_r($data);
  echo "<table class='table table-striped'>";
  echo "<tr>";
  foreach ($headers as $cell) {
	echo "<th>$cell</th>"; 
  }
  echo "</tr>";
  foreach ($data as $rows) {
    echo "<tr>";
    foreach ($rows as $cell) {
	  echo "<td>$cell</td>";
	}
	echo "</tr>";
  }
  echo "</table>";
}

Employees per Department suchen

<html>
<head>
<link rel="stylesheet" type="text/css" 
  href="bootstrap/dist/css/bootstrap.min.css">
</head>
<h2>Employees</h2>

<?php 
require_once('Util.php');
$db = oci_connect('hr', 'hr', 'kurs2.wifi');
if (empty($_GET)) { 
  $sql = "select department_id id,
                 department_name
	   from departments where department_id in 
	   (select department_id from employees)";
  $q = oci_parse($db, $sql);
  $r = oci_execute($q, OCI_DEFAULT);
  $table = array();  
  while ($row = oci_fetch_array($q, OCI_ASSOC)) { 
    $table[] = $row;	
  }   
  
?>

<form class="form-horizontal" role="form" 
    action='employees_departments.php' method='get'>
  <div class="form-group">
  <select class="col-sm-offset-2 col-sm-3" name='department'>
    <?php foreach ($table as $dep) {
	  printf("<option value='%s'>%s</option>\n", 
	     $dep['ID'], $dep['DEPARTMENT_NAME']);	   
	} 
	?>
  </select>   
  
  </div>  
  <div class="col-sm-offset-2 col-sm-10">
    <input type="submit" value="Suchen" class="btn"/> 
  </div>
</form>

<?php
} else {
  $department_id =  $_GET['department']; 
  $sql = "select first_name,
            last_name,
	        salary,
			email,
			hire_date
	   from employees where department_id = :b_department_id";

 
  $q = oci_parse($db, $sql);

  oci_bind_by_name($q, ":b_department_id",  $department_id );		  

  $r = oci_execute($q, OCI_DEFAULT);

  $table = array();  
  while ($row = oci_fetch_array($q, OCI_NUM)) { 
    $table[] = $row;	
  }   
  
  $headers = array('First Name', 'Last Name', 'Salary', 
           'Email', 'Hire Date');
  print_table($table, $headers);    
}

?>  
</html>

Employees per Department mit jquery aktualisieren

<html>
<head>
<link rel="stylesheet" type="text/css" 
  href="bootstrap/dist/css/bootstrap.min.css">
 <script src="jquery-2.1.1.min.js"></script>  
 
 
</head>


<?php 
require_once('Config.php');
require_once('Util.php');
$db = oci_connect('hr', 'hr', 'kurs2.wifi');
if (empty($_GET)) { 
  $sql = "select department_id,
                 department_name
	   from departments where department_id in 
	   (select department_id from employees)";
  $q = oci_parse($db, $sql);
  $r = oci_execute($q, OCI_DEFAULT);
  $table = array();  
  while ($row = oci_fetch_array($q, OCI_NUM)) { 
    $table[] = $row;	
  }   
  
?>
<script>
 
 $(function () {   
   $( "#depselect" ).change(function() {
	$.get("http://localhost/employees_departments_js.php?department="+
	  $( this ).val(), function( data ) {
		   $("#output").html( data );
	 });
   });
 });
 </script>
 
  <h2>Select Department</h2> 
  <div class="form-group">
  <select id='depselect' class="col-sm-offset-2 col-sm-3" name='department'>
    <?php foreach ($table as $dep) {
	   printf("<option value='%s'>%s</option>\n", $dep[0], $dep[1]);	   
	} 
	?>
  </select>
  <br>
  <div id='output'>    
  </div>
</form>

<?php
} else {
  $department_id =  $_GET['department']; 
 

  $sql = "select first_name,
            last_name,
	        salary,
			email,
			hire_date
	   from employees where department_id = :b_department_id";

 
  $q = oci_parse($db, $sql);

  oci_bind_by_name($q, ":b_department_id",  $department_id );		  

  $r = oci_execute($q, OCI_DEFAULT);

  $table = array();  
  while ($row = oci_fetch_array($q, OCI_NUM)) { 
    $table[] = $row;	
  }   
  
  $headers = array('First Name', 'Last Name', 'Salary', 
           'Email', 'Hire Date');
  print_table($table, $headers);    
}

?>  
</html>