Loop through every row in a database table in php - php

Question

I am new to php.
I am doing login for user, then I would like to compare the username and password of the person when he/she login to every rows in my database table.
For this case, assume user= michael, pssword =1234
I got this:
$username= "michael";
$password= "1234";
include("includes/connect.php");
$mobile_user = "select * from mobileuser" ;
$query = mysqli_query ($conn, $mobile_user);
while($results = mysqli_fetch_array ($query)){
$user_name = $results['mobile_user_name'];
$pass = $results['mobile_user_pass'];
}
However, this only compare to the last row of data in my database table.
For example, if username=michael n password=1234 is located in the last row of my database table, then login success, if it does not located at the last row, login failed.
Anyone can help?

Answer 1

You should modify your code as:
$username= "michael";
$password= "1234";
include("includes/connect.php");
$mobile_user = "SELECT * FROM mobileuser WHERE mobile_user_name='$username' AND mobile_user_pass='$password' LIMIT 0,1";
$query = mysqli_query ($conn, $mobile_user);
$result = mysqli_fetch_array ($query);
$user_name = $result['mobile_user_name'];
$pass = $result['mobile_user_pass'];
This should work like a charm. However a better version of this would be:
$username= "michael";
$password= "1234";
include("includes/connect.php");
$mobile_user = "SELECT count(*) as count FROM mobileuser WHERE mobile_user_name='$username' AND mobile_user_pass='$password'";
$query = mysqli_query ($conn, $mobile_user);
$result = mysqli_fetch_array ($query);
if($result['count'] > 0){
echo "Match Found.";
}

Answer 2

If you want to check if a user's credential are valid, you should count the number of rows where they match ; if this is less than one, the credentials provided are invalid. SQL query :
SELECT COUNT(*) AS number, mobile_user_name, mobile_user_pass FROM mobileuser WHERE mobile_user_name = 'someusername' AND mobile_user_pass = 'somepass'
Note that you should prevent your code from SQL injections, and you may want to store hashed passwords in your database to avoid stocking them in cleartext.

Answer 3

give this a go:
require_once ('con.php');
$q = "SELECT `password` FROM `tbl_where_user_is` WHERE `tbl_row_username` = '$username'";
$r = mysqli_query($db_connnect, $q);
$row = mysqli_fetch_array($r);
$r = mysqli_query ($db_connnect, $q);
if(mysqli_num_rows($r)==1)
{
echo $username;
}else{
echo "user not found";
}