想学习网站对接数据库的谁能给个简单的代码 网页就上两个输入框，一个提交按钮，一个查询按钮.

<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
<input type="text" name="input1" placeholder="Input 1" />
<input type="text" name="input2" placeholder="Input 2" />
<input type="submit" value="Submit" />
<input type="submit" value="Query" name="query" />
</form>
<?php
if (isset($_POST['query'])) {
// connect to database
$db = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);
if ($db->connect_error) {
die("Could not connect to database.");
}
// retrieve data from database
$input1 = $db->real_escape_string($_POST['input1']);
$input2 = $db->real_escape_string($_POST['input2']);
$sql = "SELECT * FROM table WHERE input1='$input1' AND input2='$input2'";
$result = $db->query($sql);
while ($row = $result->fetch_array()) {
echo "<p>".$row['data']."</p>";
}
// close connection
$db->close();
}
?>