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

Meta: April 11th 2008 // PHP // 42,087 views

At this point you will have a working poll system. But what if you want to add your own questions and make new polls? Simple. All you need to do is edit the contents of the database in two places.

8. Firstly open up phpmyadmin. Then click on the database you made and then on the table name poll. Here is where all your polls are stored. Click on the button Insert. Simply make a title for your poll and click go. Next click browse. You will see your entry there, along with an id number. Remember this id number and click on the table name questions.

Do the same with insert, however type in the poll id (pid) which is the number you just remembered, and then the question title. Repeat this process with the question titles and the same pollid until you have all the possible responses you want!

And thats it! You have now set up a new poll. Remember at the start of the tutorial we said we would only show the newest poll, well since your new poll has a greater id number than the previous, it is considered the newest now.

*UPDATE*
The poll bars did not extend to the entire width of the area, that is because we were using strict percentages, in comparison to the total amount of votes. In order to make the bars extend to the full width, and in doing so making the option with the most votes equal 100% we must compare all other votes with that of the most voted option. So to do so open up poll.php and:

After:

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

Add:

$query = mysql_query("SELECT COUNT(`id`) as hits FROM `responses` GROUP BY `qid`");
	while($row = mysql_fetch_array($query)){
		$me[] = $row['hits'];
	}
	$max = max($me);

Next Find:

1	$percentage = round(($responses['total'] / $total) * 100);

And replace with:

1	$percentage = round(($responses['total'] / $max) * 100);

Also another update to fix division by zero:
Find:

1	$percentage = round(($responses['total'] / $max) * 100);

Replace with:

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

Done! Now your bars are constructed in comparison to the most popular option!

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

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

// 65 comments so far.

Cristi // June 11th 2008

It would be perfect if it had a form to add the question and a form to edit them. Anyway Good Job.

VoiDeT // June 11th 2008

Yep sure.
You should take the guestbook tutorial and build that feature yourself! It is not hard at all

chor khee // July 16th 2008

nice one man! just a simple question. Can this be done using jsp and mYsql? are there any links for that?

VoiDeT // July 16th 2008

Hey Chor Khee,

I don’t know JSP, sorry.
Have fun with the port!

Ana // July 25th 2008

Thank you very much it really is great, it gave me the whole picture. I am using Access data base, how can I use this nice piece of code for Access. Thanks again.

Hunter // August 11th 2008

Hi,

I downloaded the source, and uploaded it in tact, minus editing in my database information.

I get this error:

http://www.nineprinces.org/hunter/php/tutorials/

”
Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/backline/public_html/hunter/php/tutorials/poll.php on line 4″

What’s up w/ that?

Hunter // August 11th 2008

Nm, fixed it

VoiDeT // August 11th 2008

And how did you fix it?

Hanayo // September 24th 2008

I tried working on it but I as totally lost when it came to the whole phpmyAdmin thing??

I couldn’t figure out what you were talking about the click Insert or whatever since I didn’t see that anywhere on my page…

Like I know how to read html/css fairly well and can read xhtml. But php is what I’m learning, and so i know i put the codes in all the right spots but I don’t know what you meant by that and I tried but I dont’ think i got it…

http://www.aestheticloveinc.com/poll/index.php and it’s just blank….

blckheart // September 25th 2008

RE: And how did you fix it? Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in

To fix the error, you will have to connect to the database. In the downloaded files there is no config.php file or db.inc file to connect to the database, therefore the mysql_num_rows cannot find any info from the database, because there is no connection to the database. Or at least this is what happened in my case.

To connect to the database use the following code in the poll.php file or create a seperate config.php file and just use an include ‘config.php’; or require ‘config.php’; in the top of your poll.php file

//Connection to Database
$hostName = “localhost”;
$databaseName = “yourdatabasename”;
$databaseusername = “yourdbusername”;
$dbpassword = “yourdbpassword”;

$connect = @mysql_connect($host, $yourdbusername, $yourdbpassword);
if (!mysql_select_db($databaseName, $connect))
echo ‘Could not connect to database’;

I hope this helps, i dont know why someone would ask for help on the error and then say he fixed it without giving a solution, he has the time to ask but not the time to help, i think that sucks!

VoiDeT // September 27th 2008

blckheart what do you think is sitting in the root folder? would it be a config.php file by anychance? With this code in it?

< ?php

//database settings

$hostname = 'localhost';
$username = 'yourusername';
$password = 'yourpassword';
$dbname = 'poll';

$connect = mysql_connect($hostname, $username, $password);
mysql_select_db($dbname);

Look at the files.

BlueDevil18 // September 28th 2008

I set everyhing up. Added a New Poll and Questions to the poll with the correct pid. However, when I browse to the file(poll.php) on the server, it still comes up “No Poll Yet” Am I not doing something?

BlueDevil18 // September 28th 2008

I need some help with this. I think i set up up correctly, but i still get “no poll yet”

Rkrueger // October 12th 2008

hey i was doing this and it came up with the error that the function “max()” doesn’t have enough parameters..
can someone check this out?

Hodde // October 28th 2008

I get the “no poll yet”-message too.. and i’m also pretty sure i set the poll up correctly..

Stonedeft // December 13th 2008

You should have separated codes and html. It gets real confusing I have to strip html tags the poll.php for me to review the code.

Well I got the idea but man you should recode this to for web 2.0 standards

VoiDeT // December 13th 2008

Thank you for the comment,
Web 2.0 standards in php LOL Maybe you could say something like, maybe you should use objects, or logic from design separation, but web 2.0 standards haha

Bjorn // January 13th 2009

I get the “no poll yet”-message Any solutions?

VoiDeT // January 13th 2009

Did you make sure you entered a poll into the database?

Kim // February 20th 2009

oh , nice tut, I really took a good hints here ! thanks man and thanks to everybody

victor // March 27th 2009

hi I have included index.php of this poll onto my homepage but i am getting the following error
Warning: Division by zero in C:\xampp\htdocs\tutorial\poll.php on line 46

VoiDeT // March 28th 2009

Victor – Do you have content?

victor // March 30th 2009

yes i do have content.

VoiDeT // March 30th 2009

I will review this tutorial’s content on the weekend and add in more tests hopefully.

victor // April 08th 2009

hi
i am still looking forward to the solution the problem i am having with the poll as i emailed you on the 27th march 2009….I have included index.php of this poll onto my homepage but i am getting the following error
Warning: Division by zero in C:\xampp\htdocs\tutorial\poll.php on line 46

VoiDeT // April 08th 2009

I will look tomorrow for you victor.
So you have content etc.

VoiDeT // April 08th 2009

Victor i have looked at the code and indeed yes, it divides by zero,
I haven’t tested it but it should work now with the test

VoiDeT // April 08th 2009

By the way i have reuploaded the source

arttech // April 09th 2009

RE: And how did you fix it? Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in…

I recieved the same warnings. Fixed it by editing the config.php file. It was just about making sure the “$hostname…etc” sections match with the “$connect = mysql_connect($hostname, $username, $password);
mysql_select_db($dbname);”
And, of course, all the db info was correct with no typos.

I was using dreamweaver to make a db connection. Dreamweaver likes to create its own config file and put it in a separate folder called “Connections” in the root. And it adds info to the config file that Voidet’s didn’t have.

Great tutorial. Thanks for the work you put into it.

VoiDeT // April 09th 2009

Arttech!
Thanks alot for sorting this one one!
I would never of realised this one, as i dropped dreamweaver for this very reason! It messed with my code and files when i didn’t want it to!

arttech // April 09th 2009

Sure thing.
As I am just learning php I’ve run into trouble connecting with the db just because of either incorrect include links or phrasing…

hafiz // April 10th 2009

hello voidet,

i stuck in step 2 which is “Lets set up our work space. Make a new folder on your webserver and call it ‘poll’. ”

Emm…. what did u mean by work space and new folder on your webserver???

seriously i’m a beginner… i just create a new folder (named poll) under directory : C:\Program Files\xampp\htdocs\
and paste the config.php inside poll folder

and whenever i try to navigate the config.php on my browser it shows something like this….

Warning: mysql_connect() [function.mysql-connect]: Access denied for user ‘hafiz’@'localhost’ (using password: YES) in C:\Program Files\xampp\htdocs\poll\config.php on line 10

Warning: mysql_select_db() [function.mysql-select-db]: Access denied for user ‘ODBC’@'localhost’ (using password: NO) in C:\Program Files\xampp\htdocs\poll\config.php on line 11

Warning: mysql_select_db() [function.mysql-select-db]: A link to the server could not be established in C:\Program Files\xampp\htdocs\poll\config.php on line 11

pls help me!!!

HAFIZ // April 10th 2009

owh yeah… if i want to try make it as multiple choice poll… what things i have to change in my database????

arttech // April 11th 2009

Voidet, is it possible for you to show how to use cookies or user id’s instead of ip’s?

VoiDeT // April 11th 2009

Arttech you can,
However the point here is that we want to block spam bots!
What you could do however is have a cool off period for say an hour.
Select all the IPs in the range from only an hour ago. Not sure if the database will do this but let me know how you go. If you want me to get it done i’d have to ask $10usd to paypal as i don’t have the time at the moment.
But thanks alot for your replies!

VoiDeT // April 11th 2009

Hafiz this is a multiple choice poll!
You needs to add more answers to the poll

VoiDeT // April 11th 2009

Hafiz did you sort your problem out?

alice // April 11th 2009

(Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in)

I had the problem too. I just import the sql file again and give the initial value to $me in poll.php. Then will be ok.

$me[]=0;
while($row = mysql_fetch_array($query)){
$me[] = $row['hits'];
}
$max = max($me);

But I would like to know that why $me is an array?

VoiDeT // April 11th 2009

Because it contains many elements Alice.
If it were not an array its values would get overridden each time the while looped iterated.

HAFIZ // April 11th 2009

voidet…

no… i mean how i can create a poll that allows user to tick more than one… let say the poll has 10 ans and i want to tick 3 ans…. that is what i mean… what i knew is we use the checkbox rather than radio button… right???

ermmm…. insert text type of data is not my prob… actually i got prob with “post the value of checkbox to database”… how many tables that i must create in database and what type of it… etc.

and also what are the important element needs to connect PHP with SQL for example the “connect” file…. i’m not sure about it…

can u teach me voidet???? i really need your help…

i’m in Malaysia so my online time might be different as yours….

HAFIZ // April 11th 2009

BTW thank god i found your website…. i’m searching for the best tutorial site so that i can completing my project…. just 3 more days to submit

arttech // April 12th 2009

Voidet,
Thanks for the feedback. I’ll look into the time out.

mhemel // April 16th 2009

Great Tutorial.!!! tnx for sharing one thing i want to find out! i encounter this warning message:

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

what would be the problem? tnx nwei

VoiDeT // April 16th 2009

What version of PHP are you using?
I have not come across this before.

Dan // April 21st 2009

2mhemel:
i think the problem is in $me if its not an array (if it’s ==’0′)
try to replace
$max = max($me);
with this:
if(is_array($me)) { $max = max($me); }
else { $max=’0′; }

Morris Ericsson // April 29th 2009

Hi! I really appreciate your turtorials, but also got the message No Poll Yet -and yes – I entered a poll into the database. Any solutions??

Morris Ericsson // April 30th 2009

Hi again. I have fixed my problem by using config.php instead of my own start.php. Maybe I had too much script in that page??? Now I have “insert config.php in my start.php. However, I get no value on my vote … but have not tried to solve that problem yet.

Dee // June 06th 2009

I keep getting this error…Warning: mysql_connect() [function.mysql-connect]: Can’t connect to local MySQL server through socket ‘/usr/local/mysql-5.0/data/mysql.sock’ (2) in /home/content/j/u/i/juicer40/html/apoll/config.php on line 8

Artech // July 16th 2009

Voidet. Hello again.
Polls are still working great. You can see them on this site http://www.leerepublicanwomen.com

Today I changed the questions and noticed that there is a limit on the number of characters in the poll.

Is that limit built into your tutorial somewhere that I haven’t found, or is in in the php admin on my hosting service?

Thanks again for your hard work.

VoiDeT // July 30th 2009

That’s great news!
However:
“Use this script if you like, but don’t remove the copyright tag.”

I would appreciate some support in return Paypal donations always accepted voidet :at: nightgen :dot: com

Artech // July 31st 2009

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

VoiDeT // July 31st 2009

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!

Artech // July 31st 2009

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.

VoiDeT // July 31st 2009

Hey Artech!

Really cool portfolio you have!
Love the graphics!

Artech // July 31st 2009

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.

VoiDeT // July 31st 2009

You should get into the frameworks!
Just jump into CakePHP

frank // August 24th 2009

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

VoiDeT // August 24th 2009

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

Zilus // August 25th 2009