Unable to go to next page after successfully added data to database - php

Question

Currently, I do the room booking. My scenario is after I added data and click the add button, it cannot redirect to the next page it stick with the same page. My current page is add_factory.php
Same goes happen when the data insert is duplicated, the alert message doesn't appear although I create the alert js.
Below is my current PHP code.
<?php
require_once "../../config/configPDO.php";
require_once "../../config/check.php";
if(isset($_POST['Submit']))
{
//Getting Post Values
$Fac_ID = $_POST['Fac_ID'];
// Query for validation of username and email-id
$ret="SELECT * FROM factory where (Fac_ID=:Fac_ID)";
$queryt = $conn -> prepare($ret);
$queryt->bindParam(':Fac_ID',$Fac_ID,PDO::PARAM_STR);
$queryt -> execute();
$results = $queryt -> fetchAll(PDO::FETCH_OBJ);
if($queryt -> rowCount() == 0)
{
// Query for Insertion
$sql="INSERT INTO factory(Fac_Name, Fac_ID) VALUES(:Fac_Name, :Fac_ID)";
$query = $conn->prepare($sql);
// Binding Post Values
$query->bindparam(':Fac_Name', $Fac_ID);
$query->bindparam(':Fac_ID', $Fac_ID);
$query->execute();
$lastInsertId = $conn->lastInsertId();
if($lastInsertId){
header("Location:factory.php");
}else{
echo "
<script>alert('Something wrong, please try again')</script>
<script>window.location = 'factory.php'</script>
";
}
}
else{
echo "
<script>alert('The factory you add is already exist')</script>
<script>window.location = 'factory.php'</script>
";
}
}
?>
this is my form
<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
<table width="90%">
<tr>
<td width="20%"><b>Factory Name</b></td>
<td width="50%"><input type="text" onkeyup="this.value = this.value.toUpperCase();" class="form-control" name="Fac_ID" required></td>
</tr>
</table>
<br>
<input type="submit" name="Submit" value="Add" class="btn btn-primary btn-block" onclick="return confirm('Do you want to add this factory?');">
</form>
Can anyone know how to solve?

Answer 1

First of all
it cannot redirect to the next page it stick with the same page
it's because of this, it will load in the same page:
header("Location:factory.php");
and this:
window.location = 'factory.php'
Second,the duplicate alert won't appear because the page itself is already loading in factory.php
So change your code from:
echo "
<script>alert('The factory you add is already exist')</script>
<script>window.location = 'factory.php'</script>
";
to:
echo "
<script>alert('The factory you add is already exist');
window.open("factory.php", "_blank");</script>
";
The window.open("factory.php", "_blank"); means it will redirect to other page, not on the same page.
Lastly, don't forget to add ; to every statement