Check out example codes for "connect html to mysql database". It will help you in understanding the concepts better.

Code Example 1

 $db = mysqli_connect('localhost','username','password','database_name')
 or die('Error connecting to MySQL server.');

 <h1>PHP connect to MySQL</h1>

Code Example 2

// database connection code
// $con = mysqli_connect('localhost', 'database_user', 'database_password','database');

$con = mysqli_connect('localhost', 'root', '','db_connect');

// get the post records
$txtName = $_POST['txtName'];
$txtEmail = $_POST['txtEmail'];
$txtPhone = $_POST['txtPhone'];
$txtMessage = $_POST['txtMessage'];

// database insert SQL code
$sql = "INSERT INTO `tbl_contact` (`Id`, `fldName`, `fldEmail`, `fldPhone`, `fldMessage`) VALUES ('0', '$txtName', '$txtEmail', '$txtPhone', '$txtMessage')";

// insert in database 
$rs = mysqli_query($con, $sql);

	echo "Contact Records Inserted";


Code Example 3

$con = mysqli_connect('localhost', 'root', '',’db_connect’);
The “db_connect” is our database name that we created before.
After connection database you need to take post variable from the form. See the below code
$txtName = $_POST['txtName'];
$txtEmail = $_POST['txtEmail'];
$txtPhone = $_POST['txtPhone'];
$txtMessage = $_POST['txtMessage'];

Code Example 4

$con = mysqli_connect("localhost","your_localhost_database_user","your_localhost_database_password","your_localhost_database_db");

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