Tutorial: How to build a poll system with PHP and mySQL

By VoiDeT on April 11, 2008, 48,309 views

8. Now instead of testing if the form has been submitted and then show the results, we will do much like before and test if the visitor’s IP address is in the database already for the given poll. So lets add some code to poll.php.

After:

if($rows > 0){
		$poll = mysql_fetch_array($query);
		$title = $poll['name'];
	} else {
		$title = 'No Poll Yet';
	}

Put:

$query = mysql_query("SELECT `questions`.`pid` FROM  `responses`, `questions` WHERE `responses`.`qid`=`questions`.`id` AND `responses`.`ip`='".$_SERVER['REMOTE_ADDR']."' AND pid='".$poll['id']."'");

	if(mysql_num_rows($query) > 0){

	} else {

And we need to close that bracket off so at the very end of the file put:

Great. So basically like before we are checking if there is an ip address for the poll already. If there is, then the number of rows returned will be over 0, so that part of the code is executed, if it is 0 then we show the original form again. Which reminds me, we need to display those arrays!

Just after this line:

Put in:

Now i know what you are thinking. Some of those errors will never be seen. You are right. But with PHP and any programming, you need to account for every scenario. I always program for circumstances that i know might never happen, but if they do, i know that i have my a$$ covered. Its a good mentality to have in order to uphold security. One error will happen to display however, and that is if they don’t select an option!
So now that we have our conditional statement checking for ip addresses already who have already submitted a response, lets go about showing these responses. Paste in this code between the brackets of:
if(mysql_num_rows($query) > 0){

	} else {
And no, not where the else is!
Paste this in:
$total = mysql_query("SELECT `questions`.`pid` FROM  `responses`, `questions` WHERE `responses`.`qid`=`questions`.`id` AND pid='".$poll['id']."'");
	$total = mysql_num_rows($total);
?>






		





 0){
	?>





	

 0 && $responses['total'] > 0){
						$percentage = round(($responses['total'] / $total) * 100);
					} else {
						$percentage = 0;
					}

					$percentage2 = 100 - $percentage;
			?>

			




 0){?>style="background: url('images/bar.jpg') repeat-x;">







			

Total Votes: 





	



Correct! Lots of stuff to sift through. Most of it is HTML. So don't stress. I will run through the code with you now.

					Pages: 1 2 3 4 5 6 7 8 9

Posted by VoiDeT –

Tagged as css, guide, help, how, howto, html, Internet, mysql, PHP, poll, program, Programming, system, to, tutorial, web

Categorised under PHP

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70 Comments

« Previous 1 2

Artech

voidet. Of course! Sent you some cash and put a link in.
Many thanks for your hard work!

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July 31, 2009 @ 12:03 am
VoiDeT

Hey!
Thanks alot for the donation!
I really appreciate that! If people are using the tutorial as a learning tool i’m all for it, we both can build something up that way. But if people are going to use it for their own web apps, it’s not right to just take and not give anything back

But thanks alot for the donation! I am glad it worked out for you
Also if you need any future help with anything just let me know!

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July 31, 2009 @ 10:29 am
Artech

Honestly it was a learning tool for me. And I ended up using it successfully which I thought was very cool.
I am happy to give back and may call on you again. Thanks very much.

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July 31, 2009 @ 10:57 am
VoiDeT

Hey Artech!

Really cool portfolio you have!
Love the graphics!

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July 31, 2009 @ 11:41 am
Artech

Thanks Voidet.
I enjoy working with flash. Creating with graphics in mind is usually how I approach things. But I’m getting more and more into the scripting side of things. Really appreciating the functionality and management.

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July 31, 2009 @ 1:48 pm
VoiDeT

You should get into the frameworks!
Just jump into CakePHP

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July 31, 2009 @ 2:02 pm
frank

will this code work if i want to ask a series of independant yes or no question that i want to rate separately?

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August 24, 2009 @ 11:57 pm
VoiDeT

This is a poll script.
To turn it into a survey type program would require some refactoring.
Not too much if you want it hardcoded, but alot if you want it to be dynamic

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August 24, 2009 @ 11:59 pm
Zilus

Hi, great tutorial, thanks man.

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August 25, 2009 @ 4:10 am
iz

hi, anyone know how we get the value of $responses['total'] hmm i starter in php wondering where we get the ‘total’ from? thx for any help..

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August 27, 2009 @ 11:42 am
VoiDeT

IZ please clarify here!
Do an echo $responses['total'] to output the total number of responses!

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August 27, 2009 @ 11:54 pm
Diogo

Really good tutorial!! THX!! I’m just modifying a bit to fit on my page and to my taste.

But again, thx, i learned a lot here!

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October 14, 2009 @ 8:42 am
Ralph

Hi.. nice tutoria! i have a question

Warning: Wrong parameter count for max() in C:\wamp\www\poll\poll.php on line 17

what does it mean? and how can i solve it? thanks…

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January 11, 2010 @ 3:33 pm
VoiDeT

Hey Ralph,

Below “$query = mysql_query(“SELECT COUNT(`id`) as hits FROM `responses` GROUP BY `qid`”);”
Add:

$me = array();

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January 15, 2010 @ 9:22 am
Ralph

thanks VoiDeT.. ill try it! ^__^

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January 21, 2010 @ 12:19 am
shaeeb

Hi, followed your tutorial, this is for personal learning.. im new to PHP. was a great tutorial even for those who don’t code all the time. I just had 2 questions, everything is up and working, but my main page is also called index.php, if i change the name of the index.php that you set as default would it still work fine?

also, how do i add more polls? i want to add atleast three or four questions, thanks.

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March 23, 2010 @ 2:00 am
VoiDeT

Try changing the name and see what happens.
There might be references to index.php in the code, or it could just be SELF. I forget a lot of the code in this, as this desperately needs a re-write.
If you want to add more polls or questions you should do so in the database. However you will need to cycle through the polls somehow.

Thanks,
Richard

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March 23, 2010 @ 8:49 am
Shaeeb

Thanks, I will try changing the name and see what happens, I basically want to have 3-4 polls running at the same time, if I cant sort it out I will have to stick to one poll

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March 23, 2010 @ 11:10 pm
Richard

Hi Voidet,

I clicked on the link you give above but it seems to be malfunctioning…http://www.jotlab.com/tutorials/poll/index.php
++++++++++++++++++++++++++++++++++++++++++++++++Warning: mysql_connect() [function.mysql-connect]: Access denied for user ‘voidet_jotlab’@'localhost’ (using password: YES) in /var/www/jotlab.com/public_html/tutorials/poll/config.php on line 10

Warning: mysql_select_db() [function.mysql-select-db]: Access denied for user ‘www-data’@'localhost’ (using password: NO) in /var/www/jotlab.com/public_html/tutorials/poll/config.php on line 11

Warning: mysql_select_db() [function.mysql-select-db]: A link to the server could not be established in /var/www/jotlab.com/public_html/tutorials/poll/config.php on line 11

Warning: mysql_query() [function.mysql-query]: Access denied for user ‘www-data’@'localhost’ (using password: NO) in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 3

Warning: mysql_query() [function.mysql-query]: A link to the server could not be established in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 3

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 4

Warning: mysql_query() [function.mysql-query]: Access denied for user ‘www-data’@'localhost’ (using password: NO) in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 13

Warning: mysql_query() [function.mysql-query]: A link to the server could not be established in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 13

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 14

Warning: Wrong parameter count for max() in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 17

Warning: mysql_query() [function.mysql-query]: Access denied for user ‘www-data’@'localhost’ (using password: NO) in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 19

Warning: mysql_query() [function.mysql-query]: A link to the server could not be established in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 19

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 21

Warning: mysql_query() [function.mysql-query]: Access denied for user ‘www-data’@'localhost’ (using password: NO) in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 77

Warning: mysql_query() [function.mysql-query]: A link to the server could not be established in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 77

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /var/www/jotlab.com/public_html/tutorials/poll/poll.php on line 78
++++++++++++++++++++++++++++++++++++++++++++++++++++++++
any help is always appreciated
rca08207 at bigpond dot net dot au

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April 6, 2010 @ 5:30 pm
Abhisek

A very detailed and helpful tutorial indeed. Loved it. I made a collection of all such tutorials and scripts (including this one) at 11 PHP Voting Scripts and Tutorials. I hope it would be helpful to many.

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June 13, 2010 @ 9:10 pm