how to save the $_post in the table - php

Question

im just askin how to create a form that will save the input in the $_post thingy into the table much appreciated thanks!! or can you help me fix this code or create a new one to work please? i need your help please thanks again!
<?php
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "tsukishiro";
$id = $_POST['id'];
$name = $_POST['name'];
$comment = $_POST['comment'];
$input = $_POST['input'];
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "INSERT INTO connection(ID, name, comment, input) VALUES ('null', '$name', '$comment', 'input')";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (empty($_POST["name"])) {
$nameErr = "Name is required";
} else {
$name = test_input($_POST["name"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
$nameErr = "Only letters and white space allowed";
}
}
if (empty($_POST["comment"])) {
$comment = "";
} else {
$comment = test_input($_POST["comment"]);
}
if (empty($_POST["input"])) {
$input = "";
} else {
$input = test_input($_POST["input"]);
}
function test_input($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
echo "<input type='text' name='id'>";<br><br>
echo "<input type='text' name='name'>";
echo "<input type='text' name='comment'>";
echo "<input type='text' name='input'>";
echo "<input type='submit' name='submit'>";
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>`

Answer 1

You miss $ sign for input variable
$sql = "INSERT INTO connection(ID, name, comment, input) VALUES ('null', '$name', '$comment', '$input')";

Answer 2

Add the <form> tag.
<form name="form_name" action="your_page.php" method="post">
<input type='text' name='id'>
<input type='text' name='name'>
<input type='text' name='comment'>
<input type='text' name='input'>
<input type='submit' name='submit'>
</form>
Updated:
<?php
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "tsukishiro";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
function test_input($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$id = $_POST['id'];
$name = $_POST['name'];
$comment = $_POST['comment'];
$input = $_POST['input'];
if (empty($_POST["name"])) {
$nameErr = "Name is required";
} else {
$name = test_input($_POST["name"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
$nameErr = "Only letters and white space allowed";
}
}
if (empty($_POST["comment"])) {
$comment = "";
} else {
$comment = test_input($_POST["comment"]);
}
if (empty($_POST["input"])) {
$input = "";
} else {
$input = test_input($_POST["input"]);
}
$sql = "INSERT INTO connection(ID, name, comment, input) VALUES ('null', '$name', '$comment', 'input')";
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
}
$conn->close();
?>
<form name="form_name" action="" method="post">
<input type='text' name='id'>
<input type='text' name='name'>
<input type='text' name='comment'>
<input type='text' name='input'>
<input type='submit' name='submit'>
</form>