I have some doubts about the way PDF and Excel reports are generated from PHP. In itself is a small database (my_business) containing a table (products) with 12 records ( Link to download the database)
This is the code of the Index.php that I am driving
<!DOCTYPE html>
<html lang="es">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta name="description" content="">
<meta name="author" content="">
<!-- Icono -->
<link rel="icon" type="image/png" href="img/logos/bb.ico"/>
<title>Biblioteca</title>
<!-- Estilos de letra -->
<link href='https://fonts.googleapis.com/css?family=Kaushan+Script' rel='stylesheet' type='text/css'>
<link href='https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic,700italic' rel='stylesheet' type='text/css'>
<link href='https://fonts.googleapis.com/css?family=Roboto+Slab:400,100,300,700' rel='stylesheet' type='text/css'>
<!-- Hoja de estilo -->
<link href="css/agency.css" rel="stylesheet">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-light bg-light">
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav ml-auto col-lg-9">
<li class="nav-item">
<a class="nav-link js-scroll-trigger"><h3>Bienvenido </h3></a>
</li>
</ul>
<ul class="col-lg-3 nav navbar-nav pull-xs-left">
<li class="nav-item">
<a class="pull-left" href="cerrar.php"><h3>Cerrar Sesión <i class="fa fa-user-circle" aria-hidden="true"></i></h3></a>
</li>
</ul>
</div>
</nav>
<div class="col-lg-12 text-center">
<h2 class="section-heading">Todos los registros</h2>
<h3 class="section-subheading text-muted">Modificar, eliminar e insertar nuevos registros</h3>
</div>
<!-- TABLA -->
<div class="container">
<table class="table display AllDataTables table-striped table-responsive">
<thead style="color: #5acbf5">
<tr>
<th>No</th>
<th>ID</th>
<th>Producto</th>
<th>Descripcion</th>
<th><a href="nuevo_producto1.php"><button type="button" class="btn btn-info">Nuevo</button></a></th>
</tr>
</thead>
<tbody>
<?php
include "conexion.php";
$sentencia = "SELECT * FROM productos";
$resultado = $conexion->query($sentencia) or die (mysqli_error($conexion));
while($fila = $resultado->fetch_assoc()){
echo "<tr style='color: #7dce30'>";
echo "<td>"; echo $fila['no']; echo "</td>";
echo "<td>"; echo $fila['id_producto']; echo "</td>";
echo "<td>"; echo $fila['nombre']; echo "</td>";
echo "<td>"; echo $fila['descripcion']; echo "</td>";
echo "<td><a href='modificar_producto1.php?no=".$fila['no']."'> <button type='button' class= 'btn btn-success'>Modificar</button></a></td>";
echo "<td><a href='ElimProd.php?no=".$fila['no']."'> <button type='button' class= 'btn btn-danger'>Eliminar</button></a></td>";
echo "</tr>";
}
?>
</tbody>
</table>
<thead>
<tr>
<th><a href=""><button type="button" class="btn btn-success">Excel</button></a></th>
<th><a href=""><button type="button" class="btn btn-danger">PDF</button></a></th>
</tr>
</thead>
</div>
<!-- FINAL DE TABLA -->
<script src="js/jquery-3.2.1.min.js"></script>
<script src="js/bootstrap.min.js"></script>
<!-- Pie de página -->
<footer>
<br>
<br>
<div class="container">
<div class="row">
<div class="col-md-4">
<span class="copyright">Copyright © ProjectLibrary 2017</span>
</div>
<div class="col-md-4">
</div>
<div class="col-md-4">
<ul class="list-inline quicklinks">
<li class="list-inline-item">
<a href="#">Política de privacidad</a>
</li>
<li class="list-inline-item">
<a href="#">Términos de uso</a>
</li>
</ul>
</div>
</div>
</div>
</footer>
</body>
</html>The "New", "Modify" and "Delete" buttons work, I just need the part of the Excel and PDF that, despite looking for information, I feel it is not clear to me yet, and I would really appreciate it a lot.