Why is mysql inserting a new row instead of updating it? - php

Question

My code should be checking the database to see if the custID exists, and if it does, to update the information. It it doesn't, it needs to add the customer information to the database.
Currently, when I use the code I have, each time an order is made on the website, a new custID is added to the database.
These errors are occurring:
When a new customer orders, a new row is inserted. None of the information
from the fields is put into the database, just an empty row.
When a returning customer orders, their information is drawn from the
database on a previous page, but on this page it inserts a new row and the new fields
are left blank.
If this isn't enough information or isn't clear, I will gladly offer more code and explanation.
//The information is passed through a session object from a previous page.
if (ISSET($_SESSION['fname'])) {
session_start();
$email = $_SESSION['email'];
$fname = $_SESSION['fname'];
$lname = $_SESSION['lname'];
$street = $_SESSION['street'];
$city = $_SESSION['city'];
$state = $_SESSION['state'];
$zip = $_SESSION['zip'];
$safeID = $_SESSION['safeID'];
$custID = $safeID / 507921;
}
include_once("Connection.php");
include_once("header.html");
//check if customer is already in database
$sql = "SELECT *
FROM bookcustomers
where custID = '$custID'";
$result = mysqli_query($link, $sql)
or die('SQL syntax error: ' . mysqli_error($link));
if (mysqli_num_rows($result) > 0 ) {
$sql = "UPDATE bookcustomers
set fname = '$fname',
lname = '$lname',
email = '$email',
street = '$street',
city = '$city',
state = '$state',
zip = '$zip'
WHERE custID = '$custID'";
$result = mysqli_query($link, $sql)
or die('SQL syntax error: ' . mysqli_error($link));
}
else {
$sql = "INSERT into bookcustomers (fname,
lname,
email,
street,
city,
state,
zip)
VALUES ('$fname',
'$lname',
'$email',
'$street',
'$city',
'$state',
'$zip')";
$result = mysqli_query($link, $sql)
or die('SQL syntax error: ' . mysqli_error($link));
$custID = mysqli_insert_id($link);
}

Answer 1

session_start should be called before your if clause.
session_start() creates a session or resumes the current one based on a session identifier passed via a GET or POST request, or passed via a cookie.
If you change the top if on your php file
session_start();
if (ISSET($_SESSION['fname'])) {
$email = $_SESSION['email'];
$fname = $_SESSION['fname'];
$lname = $_SESSION['lname'];
$street = $_SESSION['street'];
$city = $_SESSION['city'];
$state = $_SESSION['state'];
$zip = $_SESSION['zip'];
$safeID = $_SESSION['safeID'];
$custID = $safeID / 507921;
}
include_once("Connection.php");
include_once("header.html");
This will resume your session, as long as you created the session correctly and set the fname session variable on the previous page.
If you've set the values correctly and change the if clause to the one above, it should work.

Answer 2

Can you try this, moved session_start(); top of if (ISSET($_SESSION['fname'])) { .
<?php
session_start();
if (ISSET($_SESSION['fname'])) {
$email = $_SESSION['email'];
$fname = $_SESSION['fname'];
$lname = $_SESSION['lname'];
$street = $_SESSION['street'];
$city = $_SESSION['city'];
$state = $_SESSION['state'];
$zip = $_SESSION['zip'];
$safeID = $_SESSION['safeID'];
$custID = $safeID / 507921;
}
include_once("Connection.php");
include_once("header.html");
//check if customer is already in database
$sql = "SELECT *
FROM bookcustomers
where custID = '$custID'";
$result = mysqli_query($link, $sql)
or die('SQL syntax error: ' . mysqli_error($link));
if (mysqli_num_rows($result) > 0 ) {
$sql = "UPDATE bookcustomers
set fname = '$fname',
lname = '$lname',
email = '$email',
street = '$street',
city = '$city',
state = '$state',
zip = '$zip'
WHERE custID = '$custID'";
$result = mysqli_query($link, $sql)
or die('SQL syntax error: ' . mysqli_error($link));
}
else {
$sql = "INSERT into bookcustomers (fname,
lname,
email,
street,
city,
state,
zip)
VALUES ('$fname',
'$lname',
'$email',
'$street',
'$city',
'$state',
'$zip')";
$result = mysqli_query($link, $sql)
or die('SQL syntax error: ' . mysqli_error($link));
$custID = mysqli_insert_id($link);
}
?>