Selecting certain row in mysql - php

Question

I am completely new to MYSQL and PHP, so i just need to do something very basic.
I need to select a password from accounts where username = $_POST['username']... i couldn't figure this one out, i keep getting resource id(2) instead of the desired password for the entered account. I need to pass that mysql through a mysql query function and save the returned value in the variable $realpassword. Thanks!
EDIT:
this code returned Resource id (2) instead of the real password
CODE:
<?php
$con = mysql_connect('server', 'user', 'pass');
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
echo '<br/> ';
// Create table
mysql_select_db("dbname", $con);
//Variables
//save the entered values
$enteredusername = $_POST['username'];
$hashedpassword = sha1($_POST['password']);
$sql = "SELECT password from accounts where username = '$enteredusername'";
$new = mysql_query($sql,$con);
echo "$new";
if (!mysql_query($sql,$con))
{
die('Error: ' . mysql_error());
}
mysql_close($con);
?>

Answer 1

It will be a lot better if you use PDO together with prepared statements.
This is how you connect to a MySQL server:
$db = new PDO('mysql:host=example.com;port=3306;dbname=your_database', $mysql_user, $mysql_pass);
And this is how you select rows properly (using bindParam):
$stmt = $db->prepare('SELECT password FROM accounts WHERE username = ?;');
$stmt->bindParam(1, $enteredusername);
$stmt->execute();
$result = $stmt->fetch(PDO::FETCH_ASSOC);
$password = $result['password'];
Also, binding parameters, instead of putting them immediately into query string, protects you from SQL injection (which in your case would be very likely as you do not filter input in any way).

Answer 2

I think your code looks something like this
$realpassword = mysql_query("SELECT password
from accounts where username = '$_POST[username]'");
echo $realpassword;
This will return a Resource which is used to point to the records in the database. What you then need to do is fetch the row where the resource is pointing. So, you do this (Note that I am going to use structural MySQLi instead of MySQL, because MySQL is deprecated now.)
$connection = mysqli_connect("localhost", "your_mysql_username",
"your_mysql_password", "your_mysql_database")
or die("There was an error");
foreach($_POST as $key=>$val) //this code will sanitize your inputs.
$_POST[$key] = mysqli_real_escape_string($connection, $val);
$result = mysqli_query($connection, "what_ever_my_query_is")
or die("There was an error");
//since you should only get one row here, I'm not going to loop over the result.
//However, if you are getting more than one rows, you might have to loop.
$dataRow = mysqli_fetch_array($result);
$realpassword = $dataRow['password'];
echo $realpassword;
So, this will take care of retrieving the password. But then you have more inherent problems. You are not sanitizing your inputs, and probably not even storing the hashed password in the database. If you are starting out in PHP and MySQL, you should really look into these things.
Edit : If you are only looking to create a login system, then you don't need to retrieve the password from the database. The query is pretty simple in that case.
$pass = sha1($_POST['Password']);
$selQ = "select * from accounts
where username = '$_POST[Username]'
and password = '$pass'";
$result = mysqli_query($connection, $selQ);
if(mysqli_num_rows($result) == 1) {
//log the user in
}
else {
//authentication failed
}
Logically speaking, the only way the user can log in is if the username and password both match. So, there will only be exactly 1 row for the username and password. That's exactly what we are checking here.

Answer 3

By seeing this question we can understand you are very very new to programming.So i requesting you to go thru this link http://php.net/manual/en/function.mysql-fetch-assoc.php
I am adding comment to each line below
$sql = "SELECT id as userid, fullname, userstatus
FROM sometable
WHERE userstatus = 1"; // This is query
$result = mysql_query($sql); // This is how to execute query
if (!$result) { //if the query is not successfully executed
echo "Could not successfully run query ($sql) from DB: " . mysql_error();
exit;
}
if (mysql_num_rows($result) == 0) { // if the query is successfully executed, check how many rows it returned
echo "No rows found, nothing to print so am exiting";
exit;
}
while ($row = mysql_fetch_assoc($result)) { //fetch the data from table as rows
echo $row["userid"]; //echoing each column
echo $row["fullname"];
echo $row["userstatus"];
}
hope it helps

Answer 4

try this
<?php
$con = mysql_connect('server', 'user', 'pass');
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
echo '<br/> ';
// Create table
mysql_select_db("dbname", $con);
//Variables
//save the entered values
$enteredusername = mysql_real_escape_string($_POST['username']);
$hashedpassword = sha1($_POST['password']);
$sql = "SELECT password from accounts where username = '$enteredusername'";
$new = mysql_query($sql,$con);
$row = mysql_fetch_array($new) ;
echo $row['password'];
if (!$new)
{
die('Error: ' . mysql_error());
}
mysql_close($con);
?>

Answer 5

<?php
$query = "SELECT password_field_name FROM UsersTableName WHERE username_field_name =".$_POST['username'];
$result = mysql_query($query);
$row = mysql_fetch_array($result);
echo $row['password_field_name'];
?>

Answer 6

$username = $_POST['username'];
$login_query = "SELECT password FROM users_info WHERE users_info.username ='$username'";
$password = mysql_result($result,0,'password');