<?php
    $dbhost = "localhost";
    $username = "root";
    $pass = "";
    $conn = mysql_connect("$dbhost" , "$username" , "$pass");
     if(!$conn)
     {
         die("connection failed : ". mysqli_connect_error());
     }
     else{
         echo "Database connected Successfully!!!";
     }
    $db = mysql_select_db("table1",$conn);
    //$sql = "SELECT * from table1 WHERE id = 1";
    $sql = "INSERT INTO table1 (ID, Name,Designation) Designation)VALUES(NULL,'abhishek','Student')";
    $query = mysql_query($conn , $sql);
?>

Database connected Successfully!!!
Warning: mysql_query() expects parameter 1 to be string, resource given in    C:xampphtdocsTestDatabase1.php on line 16

$sql = "INSERT INTO table1 (ID, Name,Designation) Designation)VALUES(NULL,'abhishek','Student')";

$sql = "INSERT INTO table1 (ID, Name,Designation) VALUES(NULL,'abhishek','Student')";