php connect

1<?php
2$servername = "localhost";
3$username = "username";
4$password = "password";
5$dbname = "myDB";
6
7// Create connection
8$conn= mysqli_connect($servername,$username,$password,$dbname);
9// Check connection
10if (!$conn) {
11  die("Connection failed: " . mysqli_connect_error());
12}
13echo "Connected Successfully.";
14?>

1$servername = "localhost";
2$username = "username";
3$password = "password";
4
5// Create connection
6$conn = new mysqli($servername, $username, $password);
7
8// Check connection
9if ($conn->connect_error) {
10    die("Connection failed: " . $conn->connect_error);
11}
12echo "Connected successfully";
13
14
15Simplified
16
17$conn = mysqli_connect('localhost', 'username', 'password');
18$database = mysqli_select_db($conn, 'database');

1# MySql improved
2<?php
3    $mysqli = new mysqli("localhost", "username", "password", "dbname");
4	$result = $mysqli->query("SELECT lastname FROM employees");
5?>
6# Connection with PDO
7<?php
8    $myPDO = new PDO('mysql:host=localhost;dbname=dbname', 'username', 'password');
9	$result = $myPDO->query("SELECT lastname FROM employees");
10?>
11# With PHP legacy functions:
12<?php
13    mysql_connect('localhost','username','password');
14    mysql_select_db("dbname");
15	$result = mysql_query('SELECT lastname FROM employees');
16?>

1<?php
2$mysql_hostname = "localhost";
3$mysql_user = "root";
4$mysql_password = "";
5$mysql_database = "hms";
6$bd = mysqli_connect($mysql_hostname, $mysql_user, $mysql_password, $mysql_database) or die("Could not connect database");
7
8?>