使用php将mysql中的数据打印成pdf文件

Question

I am using FPDF for the PDF and so far in my search I saw this similar question to my question and followed the code there and when I ran it no Error was being called and the PDf can be downloaded. But the problem is when I open the PDF file it is empty and I can't seem to understand the problem. This is my PHP code:

<?php
include("connections.php");
require("fpdf181/fpdf.php");
$pdf = new FPDF(); 
$name = $address = $email = "";
$nameErr = $addressErr = $emailErr = "";

if($_SERVER["REQUEST_METHOD"] == "POST"){ 
if(empty($_POST["name"])){
    $nameErr = "Name is required!";
}else{
    $name = $_POST["name"];
}
if(empty($_POST["address"])){
    $addressErr = "Address is required!";
}else{
    $address = $_POST["address"];
}
if(empty($_POST["email"])){
    $emailErr = "Email is required!";
}else{
    $email = $_POST["email"];
}   
}
//When button is clicked the pdf will be generated
if (isset($_POST["btn_1"])) {
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('','',12);

$view_query = mysqli_query($connections, "SELECT * FROM sample");
//where the database is accessed
while ($row = mysqli_fetch_assoc($view_query))
{
$db_name = $row["Name"];
$db_address = $row["Address"];
$db_email = $row["Email"];

$pdf->Cell(0,10,'', $db_name,1); 
$pdf->Ln();
$pdf->Cell(0,10,'', $db_address,1); 
$pdf->Ln();
$pdf->Cell(0,10,'', $db_email,1); 
$pdf->Ln();
}
$pdf->Output();

}
?>
<style>
.error{
color:red;  
}
</style>

<form method = "POST" action= "<?php htmlspecialchars("PHP_SELF");?>">

<input type = "text" name="name" value="<?php echo $name; ?>"><br>
<span class = "error"><?php echo $nameErr;?></span><br>

<input type = "text" name="address" value="<?php echo $address; ?>"><br>
<span class = "error"><?php echo $addressErr;?></span><br>

<input type = "text" name="email" value="<?php echo $email; ?>"><br>
<span class = "error"><?php echo $emailErr;?></span><br>

<input type = "submit" value="Submit">

<input type = "submit" name="btn_1" value="PDF">

</form>

<?php
// Insert to table
if($name && $address && $email){
$query = mysqli_query($connections, "INSERT INTO sample(Name,Address,Email) 
VALUES('$name','$address','$email')");

echo "<script language='javascript'>alert('New Record has been inserted!')
</script>";
echo"<script>window.location.href='index.php';</script>";
}
//view table
$view_query = mysqli_query($connections, "SELECT * FROM sample");
echo"<table border = '1' width ='50%'>";
echo "<tr>
<td>Name</td>
<td>Address</td>
<td>Email</td>
</tr>";
while ($row = mysqli_fetch_assoc($view_query)) {

$db_name = $row["Name"];
$db_address = $row["Address"];
$db_email = $row["Email"];
echo "<tr>
<td>$db_name</td>
<td>$db_address</td>
<td>$db_email</td>
</tr>";
    }
echo "</table>";
mysqli_close($connections);
?>

Answer 1

This line

$pdf->SetFont('','',12);

sets your font to current font.

But you didn't set any font earlier, so fpdf doesn't know, which font to use.

So, first, you need to set font as described in SetFont manual page.

Next, is Cell function. It's definition is

Cell(float w [, float h [, string txt [, mixed border [, int ln [, string align [, boolean fill [, mixed link]]]]]]])

See? Text which you want to write to pdf comes as third parameter.

In you call

$pdf->Cell(0,10,'', $db_name,1); 

third parameter is what? Empty string, I suppose.

So, second, you need to fix your Cell calls.