create an entry in member table when table is created and wont create again php pdo

Question

This answer provides a user and password when database is created. I just want to know if this is the answer I am looking for.

I am creating several tables in php pdo and one table is specifically for member. In this table I want to create a limited number of users and specified already (no registration needed). I want to make it in a way that when the database is created the member table will be populated and it will not be populated again to avoid double entry.

I the answer he has user privilege it will be a good function if I have that but I am not familiar with it yet unfortunately he did not provide any explanation on how to make it. I am wondering if there are any others who can provide a tutorial or suggestion on my problem. Any suggestion is much appreciated.

UPDATE:

<?php 
global $dbh;
$dbname = 'memberdb';
$member = "member";
    try {
        $dbh = new PDO("mysql:host=localhost", "root", "");
        $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $dbname = "`".str_replace("`","``",$dbname)."`";
        $dbh->query("CREATE DATABASE IF NOT EXISTS $dbname");
        $dbh->query("use $dbname"); 
    $dbh->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
    $sql ="CREATE TABLE IF NOT EXISTS $member ( 
        mem_id int(40) NOT NULL AUTO_INCREMENT PRIMARY KEY,
        username VARCHAR(40) NOT NULL, 
        password VARCHAR(40) NOT NULL);" ;
        $dbh->exec($sql); 


    } catch(PDOException $e) {

}
?>

This is config.php where I create my database and table:

<?php 
include('config.php');
session_start();


$stmt = $dbh->prepare("SELECT * FROM member") ;
    $stmt->execute();
    $count = $stmt -> rowCount();
    if( $count == 00 ){
        $stmt = $dbh->prepare("INSERT INTO member (username, password) VALUES (?,?)")or die($db->errorInfo());
        $stmt->bindValue(1,"admin1",PDO::PARAM_STR);
        $stmt->bindValue(2,"password1",PDO::PARAM_STR);
        $stmt->execute();
        $stmt->bindValue(1,"admin2",PDO::PARAM_STR);
        $stmt->bindValue(2,"password2",PDO::PARAM_STR);
        $stmt->execute();
        $stmt->bindValue(1,"admin3",PDO::PARAM_STR);
        $stmt->bindValue(2,"password3",PDO::PARAM_STR);
        $stmt->execute();
    }
function ChangePassword() {
    global $dbh;
    $oldpass = trim($_POST['oldpass']);
        $newpass = trim($_POST['newpass']);
        $cpass = trim($_POST['cpass']);
        $user = $_SESSION['login_user'];
if(!empty($_POST['oldpass'])){
        $oldpass = trim($_POST['oldpass']);
        $newpass = trim($_POST['newpass']);
        $cpass = trim($_POST['cpass']);
        $user = $_SESSION['login_user'];
        $stmt = $dbh->prepare("SELECT * FROM member WHERE username = ? ") ;
        $stmt->bindValue(1,$user);
        $stmt->execute();
        $selected_row = $stmt->fetch(PDO::FETCH_ASSOC);
        echo $selected_row['mem_id'];
        echo $cpass;
        if($selected_row['password']===$oldpass){
            if($newpass===$cpass){
            $oldpass = trim($_POST['oldpass']);
        $newpass = trim($_POST['newpass']);
        $cpass = trim($_POST['cpass']);
        $user = $_SESSION['login_user'];
            $stmt = $dbh->prepare("UPDATE member SET password=:NEWPASSWORD WHERE mem_id=:ID");
            $selected_row = $stmt->fetch(PDO::FETCH_ASSOC);
            $stmt->bindValue(':ID',$selected_row['mem_id'],PDO::PARAM_STR);
            $stmt->bindValue(':NEWPASSWORD',$cpass,PDO::PARAM_STR);
            if($stmt->execute()){
                echo "<script type='text/javascript'>alert('Password Changed');

                </script>";
                exit;
                }else{
                    echo "<script type='text/javascript'>alert('Password not Changed');
                    window.location='dashboard.php';
                    </script>";
                    exit;
                }

            }else{
                echo "<script type='text/javascript'>alert('Password new password and confirm password does not match');
                window.location='dashboard.php';
                </script>";
                exit;
            }
        }else{
            echo "<script type='text/javascript'>alert('Wrong old password');
            window.location='dashboard.php';
            </script>";
            exit;
        }
}else{
    echo "<script type='text/javascript'>alert('Empty old password');
    window.location='dashboard.php';
    </script>";
    exit;
}
}
?>

This is the crud file where I create the entry but the changepassword is not working. When I run it, it goes to if($stmt->execute()) and it prompts the password changed but in the database it does not change.

Answer 1

When $stmt->execute() returns true it does not mean the password was updated. It just means that the query executed properly.

In order to find out you need to check how many rows the UPDATE query has affected, use rowCount:

if($stmt->execute()){
    if($stmt -> rowCount() >0){
        echo "<script type='text/javascript'>alert('Password Changed');</script>";
        exit;   
    }else{
        echo "<script type='text/javascript'>alert('Password not Changed');
        window.location='dashboard.php';
        </script>";
        exit;   
    }
}else{
    echo "<script type='text/javascript'>alert('Error Occured');</script>";
    var_dump($stmt->error());
    exit;
}