registration.php

<?php
    require "init.php";

    $name = $_POST["Name"];
    $email = $_POST["Email"];
    $phone = $_POST["Phone"];
    $age = $_POST["Age"];
    $password = $_POST["Pass"];

    $sql_query_for_check_existing_user = "select * from patientinfo where Phone like '$phone';";
    $result = mysqli_query($con,$sql_query_for_check_existing_user);


    if(mysqli_num_rows($result)>0)
    {
        echo "This Phone ".$phone." Number Already Exist...";
    }
    else
    {
        $sql_query = "insert into patientinfo values('$name','$email','$phone','$age','$password');";
        mysqli_query($con,$sql_query);
    }
    mysqli_close($con);
?>