Load CSV values then search for matches in mysql database - mysql

Question

I'm trying to build a script for a cron job that loads some values from a CSV file. This CSV file has 2 fields
product_id
price
The script will load the values from CSV, then it searches in mysql table for product_id matches. If found, it will update the price for that particular matched product_id in the table with the corresponding price in CSV.
I reached the below code so far but I got stuck at the part where I need to compare the array values from CSV with the array values from mysql.
<?php
// DB part
$con = mysqli_connect('localhost','user','pass','db');
if (!$con)
{
die('Could not connect: ' . mysqli_error($con));
}
mysqli_select_db($con,"products");
$sql="SELECT product_id, price, FROM products";
$result = mysqli_query($con,$sql);
$row = mysqli_fetch_array($result);
// CSV part
$file_handle = fopen("prices.csv", "r");
while (!feof($file_handle) ) {
$line_of_text = fgetcsv($file_handle, 1024);
$code = str_replace(' ', '', $line_of_text[0]); //
$price = str_replace(' ', '', $line_of_text[1]); //
if (in_array($code, str_replace(' ', '', $row)))
{
echo "Match found";
print $code . " - " . $price . "<br />";
}
else
{
echo "Match not found";
print $code . " - " . $price . "<br />";
}
}
fclose($file_handle);
mysqli_close($con);
?>

Answer 1

You're storing just the first line of your products table in $row. Then you are doing some hard-to-understand comparisons, but all of those comparisons compare just your first row.
Here's what I'd do:
// Untested Code Below, Not Suited For Production Use
// ...
// open the DB connection, open the file, etc.
// ...
// iterate over the complete CSV file
while (!feof($file_handle) ) {
$line_of_text = fgetcsv($file_handle, 1024);
$product_id = clean_product_id($line_of_text[0]);
$price = $line_of_text[1];
// for any entry in the CSV file check if there is more than one result
$sql="SELECT COUNT(*) FROM products WHERE product_id='$product_id'";
$result = mysqli_query($con,$sql);
$row = mysqli_fetch_array($result);
if( $row[0] == 1 ) {
// update the table price for the corresponding row (product), if there is just a single result for this $product_id
$sql="UPDATE products SET price = '$price' WHERE product_id='$product_id' LIMIT 1"; // in production code use mysqli_real_escape_string() on $price and $product_id!
$result = mysqli_query($con,$sql);
} else {
// if there are more results for this $product_id, add an error to your report.txt file
}
}