MYSQL query

Anthony_john5

I was hoping that my script would
i) Connect to my MYSQL database
ii) Perform a query to find the value of 'voted' in the 'votes' table
iii) If the value was '0' display 'Thanks for voting' and if it was '1' display 'You have already voted today

Here's my script:

<?php
$link = mysql_connect("localhost", "myusername", "mypwd")
        or die("Could not connect: " . mysql_error());

$result = mysql_query ("SELECT voted FROM votes")
    or die("Invalid query");

	if ($result == 1)
{

echo "You have already voted today";

}

elseif ($result == 0)

{

echo "Thanks for voting";

}



?>

When I load the page it's just completely blank, other than the Lycos advert. Can anyone make corrections to the script please.

laserlight

maybe check with

else
{
echo $result;
}

siwis

Here's where good database design comes into the fray;

Create a seperate table with two fields poll_id and user_id

You then query that table using the poll_id and user_id

$voted = mysql_query("SELECT poll_id, user_id FROM votes WHERE poll_id = '$poll_id' AND user_id = '$user_id'", $db);
$hasvoted = mysql_num_rows($voted);
if ($hasvoted != "0") {
echo "Sorry, you can't vote twice";
} else {
// Process VOTE
echo "Thanks for voting";
};

siwis

Of course I forgot to mention that part of processing a vote needs to be the insertion of a row in the votes table with the corresponding user_id and poll_id to prevent that user from voting again.

Anthony_john5

It's not a poll script, I was hoping to eventually be able to intergrate it with phpBB. I don't have the time at the moment to go into details but, at the moment all this script needs to do is check 'Voted' inside the 'Votes' table to see if the value is '1' or '0'. If it's '0' I want it to display 'Thanks for voting' and if it's '1' I want it to display 'You have already voted today. Thanks for your previous help, it'll probably come in useful later, would it be possible for you to make corrections to my script to do the above.

-Anthony 🙂

siwis

It would work in exactly the same way.

Run your query as you have it, then use

$voted = mysql_num_rows($result);
if ($voted != 0 ) {
// Test failed
} else {
// Test Passed
};

Anthony_john5

Okay I made the changes you said here's my new script

<?php
$link = mysql_connect("localhost", "insert username", "insert password")
        or die("Could not connect: " . mysql_error());

$result = mysql_query ("SELECT voted FROM votes")
    or die("Invalid query");
	$voted = mysql_num_rows($result); 
		if ($voted != 0)
	{

echo "Thanks for voting";

}

else 

{

echo "You have already voted today";

}



?>

However for some reason however many times I run the script playing around with different values in the db it still returns 'Thanks for voting' I can't see why in the script it would do that. Then again it could be something to do with IE caching the data? Could somone click here http://members.lycos.co.uk/anthonyjohn5/scripts/voting.php and post what message they receive. Thanks in advance.

-Anthony

siwis

You have your arguments back to front:

If you look at what I put....

$voted = mysql_num_rows($result); 
if ($voted != 0 ) { 
// Test failed 
} else { 
// Test Passed 
};

Note that we test for the value of $voted being NOT EQUAL to 0 ie there is an entry therefore the user HAS voted therefore the test FAILED

If the value of $voted IS 0 then the test passes, ie the user has NOT voted.

$voted = mysql_num_rows($result); 
        if ($voted != 0)
    {

echo "You have already voted today";

}

else 

{

echo "Thanks for voting";

}

Anthony_john5

Thanks for that explanation, my script looks fine now. However when I was running it whatever the database was set to is displayed 'Thanks for voting' I deleted the 'votes' database hoping I would be able to recreate it. As one final helper do you think it would be possible for you talk me through creating the MYSQL database again. I'm using phpMyAdmin. Any help with me learning php and MYSQL will be once again greatly appreciated.

-Anthony

Anthony_john5

I'd really appreciate it if someone could help me🙂

Anthony_john5

bump

siwis

In truth no, I can't help you rebuild your database. At the end of the day I don't know what it was in the first place. Why didn't you just run a "DELETE FROM votes" SQL which would have simply emptied all records but left your table intact.

BuzzLY

Anthony, please do not bump your posts. If someone has an answer for you, they'll give it to you. Don't take no answer as being ignored. Perhaps you could look elsewhere to find out what you need to know.

I would start with the MySQL documentation first. It should explain how to create a table.