Login in php with two queries in mysql_query

Question

I am trying to create a voting system in PHP. Apart from creating a standard table with 'USER' and 'PASS' as fields to contain login information, I created another table with fields : 'USER' and 'CHECK' where 'CHECK' is a binary INT with a default value of "0". But when a student votes, the 'CHECK' field is updated to '1'.

I have the login script designed such that it first checks for a record in 'USER' and 'PASS', then checks for another record in the 'USER' and 'CHECK' table for a default value of "0" to allow voting. If its "1", it redirects to an 'AlreadyVoted.htm' page.

<?php
session_start();
$_SESSION['StudentID']=$_POST['UserID'];

include 'db_conneck.php';

$studentid=mysql_real_escape_string($_POST['UserID']);
$userpass=mysql_real_escape_string($_POST['LogPass']);
$sql="SELECT * FROM user_login WHERE studentid='$studentid' and password='$userpass'";
$sql1="SELECT * FROM check_login WHERE studentid='$studentid' and check='0'";
$sql2="SELECT * FROM check_login WHERE studentid='$studentid' and check='1'";
$result=mysql_query($sql);
$result1=mysql_query($sql1);
$result2=mysql_query($sql2);
$count=mysql_num_rows($result);
$count1=mysql_num_rows($result1);
$count2=mysql_num_rows($result2);

if ($count==1 and $count1==1){
    header ("location:FirstVote.php");
}
else if ($count==1 and $count2==1){
    header ("location:AlreadyVoted.html");
}
else {
    echo "Information Not On Database";
}
exit()
?>

However I get this error

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\xampp\FirstVotePage\LoginCombo.php on line 13

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\xampp\FirstVotePage\LoginCombo.php on line 14 Information Not On Database

I think it would be easier using a `LEFT JOIN`to join the two tables together ON the studentid, then you only need one query and not 3. — jdepypere, Aug 05 '13 at 09:29
It'd be better in every possible conceivable way to _not_ use `mysql_*` at all, it's been deprecated, and its use has been discouraged for quite some time. Check any of the doc pages of any of the `mysql_*` functions and _read_ the red warning box — Elias Van Ootegem, Aug 05 '13 at 09:33
could you @arbitter exactly help me on how to use the `LEFT JOIN` query function?.. Thank You — RowVitz, Aug 05 '13 at 12:39
There is **no more support** for `mysql_*` functions, they are [**officially deprecated**](https://wiki.php.net/rfc/mysql_deprecation), **no longer maintained** and will be [**removed**](http://php.net/manual/en/function.mysql-connect.php#warning) in the future. You should update your code with [PDO](http://php.net/pdo) or [MySQLi](http://php.net/msqli) to ensure the functionality of your project in the future. — tereško, Aug 05 '13 at 23:29

score 1 · Answer 1 · answered Aug 05 '13 at 09:29

1

$result=mysql_query($sql) or die(mysql_error());
$result1=mysql_query($sql1) or die(mysql_error());
$result2=mysql_query($sql2) or die(mysql_error());

Note : The mysql extension is deprecated and will be removed in the future.

answered Aug 05 '13 at 09:29

som

4,614
2
19
36

score 1 · Answer 2 · answered Aug 05 '13 at 09:35

1

CHECK is reserved keyword you should escape it by backticks.

use those queries instead.

 $sql1="SELECT * FROM check_login WHERE studentid='$studentid' and `check`='0'";
 $sql2="SELECT * FROM check_login WHERE studentid='$studentid' and `check`='1'";

answered Aug 05 '13 at 09:35

echo_Me

36,552
5
55
77

score 0 · Answer 3 · answered Aug 05 '13 at 09:34

0

there is problem in query try to echo the query and then try executing it manually in database.

your query is returning boolean value of false instead of resource.

answered Aug 05 '13 at 09:34

score 0 · Answer 4 · answered Aug 05 '13 at 11:47

0

Note: I'am still surprised that some PHP programmers still using or die in combination with mysql_error() or give it as example code, hackers love it because of the information leaks...

answered Aug 05 '13 at 11:47

Raymond Nijland

11,193
2
18
32

THANKS A LOT . the check correction is working but the query doesnt seem to be working. Can anyone please help on the **LEFT JOIN** function in mysql-query? – RowVitz Aug 05 '13 at 12:21

Login in php with two queries in mysql_query

4 Answers4