Can't get form data to post using mySQLi - php

Question

Almost identical to a previous question however I am now trying to use mySQLi to record some form data.
After I submit, the data does not post to the table. I've been reading through to the mySQLi documentation and some different videos but I can't figure it out.
Thanks in advance!
<?php
include('config.php');
if (
isset($_POST['store_id']) &&
isset($_POST['item_title']) &&
isset($_POST['date']) &&
isset($_POST['price'])
)
{
$store = get_post('store_id');
$item = get_post('item_title');
$date = get_post('date');
$price = get_post('price');
$query = "INSERT INTO ebay_data VALUES('".$store."', '".$item."', '".$date."', '".$price."')";
$input = $db_mysqli->query($query);
}
?>

Answer 1

You want to make sure your config is actually connecting of course. I typically just go to do it on one page if I get stuck, either way try:
$mysqli = new mysqli('localhost', 'my_user', 'my_password', my_databasename);
/* check connection */
if (mysqli_connect_errno()) {
printf('Connect failed: %s\n', mysqli_connect_error());
exit();
}
$query = 'INSERT INTO ebay_data VALUES($store, $item, $date, $price)';
$mysqli->query($query);
printf ('New Record has id %d.\n', $mysqli->insert_id);
/* close connection */
$mysqli->close();
See if you get anything out on the page. Also should double check your post values are not empty. I have also ran into weird problems where setting the post to a var messed up sql queries, maybe try:
if (isset($_POST['store_id']) && isset($_POST['item_title']) && isset($_POST['date']) && isset($_POST['price']))
{
$query = "INSERT INTO ebay_data VALUES($_POST['store_id'], $_POST['item_title'], $_POST['date'], $_POST['price'])";
...
You also 100% need to check those post values, keeping your database and users safe. Prepared statements is a start. You do need a lot more than that though to keep it safe...
http://php.net/manual/en/mysqli.quickstart.prepared-statements.php