Untitled

<?php

ini_set('display_errors', '1');
error_reporting(E_ALL);

$DB_HOST = "localhost";
$DB_USER = "sassha";
$DB_PASS = "";
$DB_NAME = "test";

$db = new mysqli($DB_HOST, $DB_USER, $DB_PASS, $DB_NAME);

if ($db->connect_errno) {
printf("1");
exit();
}

$result = $db->query("
CREATE TABLE IF NOT EXISTS test_table (
id INT AUTO_INCREMENT,
data TEXT,
PRIMARY KEY (id)
);
");

echo strval($result);

if (!$result) {
printf("2: %s", $db->error);
exit();
}

if (!empty($_REQUEST["data"])) {
$query = $db->prepare("
INSERT INTO test_table (id, data)
VALUES (1, ?)
ON DUPLICATE KEY
UPDATE id = 1, data = ?;
");

$query->bind_param("ss", $_REQUEST["data"], $_REQUEST["data"]);

$result = $query->execute();

if (!$result) {
printf("3: %s", $query->error);
}

$query->close();
}

?>

<!DOCTYPE html>
<html lang="ru">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>

<form method="post">
<input type="text" name="data">
<button type="submit">
Send
</button>
</form>

<br>

<form action="." method="post">
<input type="hidden" name="get" value="true">
<button type="submit" href="#">
Get data
</button>
</form>
</body>

<p>
<?php
if (!empty($_REQUEST["get"])) {
$result = $db->query("
SELECT data
FROM test_table
WHERE id = 1;
");

if (!$result) {
printf("Не удалось получить данные: %s", $db->error);
exit();
}

while($row = $result->fetch_assoc()) {
printf($row["data"]);
}
}
?>
</p>

</html>

<?php

$db->close();