Comparing user input data to mysql db
Question
so i've recently got a job at a market, and they got a lot of PLU's that i need to know. So for helping me, i'm trying to do something to help me.
I've created a database with some of the items that look like this:
id art img plu_code
and in my index.php, after connecting to database and selecting a random id to show
$query = "SELECT * FROM produto ORDER BY RAND() LIMIT 1";
if ($result = $mysqli->query($query)) {
while ($row = $result->fetch_assoc()) {
$imagem_produto = $row["imagem"];
$nome_produto = $row["artigo"];
$plu_produto = $row["plu"];
echo '<center><tr>
<td><img height="150" width="150" src="'.$imagem_produto.'"></td><br>
<td>'.$nome_produto.'</td><br>
<td>'.$plu_produto.'</td>
</tr></center>';
}
$result->free();
if ($plu_produto === $_GET['U']) {
echo "Correct. Please wait!";
header("Refresh:3");
}else{
echo 'Wrong.';
}
}
?>
<html>
<body>
<form method="post">
<input type="text" name="U"/>
<input type="submit" />
</form>
</body>
</html>
How do i compare the user input to the db and then show if it's correct or wrong? Thank you!
2 answers
solution1
0 2020-01-08 18:13:45
It is not like comparing the user input to the db.
Your code
if ($_POST['U'] === $plu_produto) {
compares with the last row read by the while loop which is not as expected.
After connecting to the database, have code to show all data which will show up in the first run. And after the user input you should select the relevant rows from the database itself which matches with "U" where there should not be any while loop but the sql select itself should return only one row.
solution2
0 2020-01-08 20:15:29
You should just query for the specific PLU, not the entire table.
You also need to use $_POST , not $_GET , since the form has method="POST" .
if (isset($_POST['U'])) {
$plu_produto = $_POST['U'];
$stmt = $mysql->prepare("SELECT 1 FROM produto WHERE plu = ?");
$stmt->bind_param("s", $plu_produto);
$stmt->execute();
$stmt->store_result();
if ($stmt->num_rows > 0) {
echo "Correct. Please wait!";
header("Refresh:3");
}else{
echo 'Wrong.';
}
exit;
}
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