if count > 0 isnt working. Trying to set a URL differently to display if there is a new message to be read.

Question

0.00/5 (No votes)

See more:

Hi,

Im trying to get my messages link to show if there is a new message to the user that is currently signed in to the session.

In the messages database table, 0 is unread and 1 is read so any messages that are unread and sent to the session username should be returned. Currently, there are no rows being returned (because all messages are read (or 1)) so the link should not show the '(new)' part but it does. I changed the count($success) to > 1 and the code in the else was executed.

Here is my code:

PHP

$s_username = $_SESSION['username'];

$db = Database::getConnection();
				$query = 'SELECT * FROM messages WHERE messageTo = :to AND messageRead = 0';
				$output = $db->prepare($query);
				$output->bindParam(':to', $s_username);
				$success = $output->execute();
					if (count($success) > 0){
						$msg = '<li><a href="messages.php">My Messages (new)</a></li>';
					} else {
						$msg = '<li><a href="messages.php">My Messages</a></li>';
					}
				echo $msg;

Am I missing something obvious? I understand that if there are no rows then it does = 0 because its empty, but if it is greater than and there are unread messages to the session user, it should work, right?

Posted 7-Apr-15 11:50am

jba1991

Add a Solution

Comments

ramyajaya 7-Apr-15 18:25pm

Your logic is correct. Check if the query executes manually and the query formed is correct.

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sascha Lefèvre · Accepted Answer · 2015-04-07T18:34:00

Solution 1

This:

PHP

$success = $output->execute();

only returns true or false, indicating the query execution was successful or not - it does not return the amount of records returned.
See: http://php.net/manual/en/pdostatement.execute.php[^]

To get the amount of records returned, use rowCount():
http://php.net/manual/en/pdostatement.rowcount.php[^]

But if you are only interested in the amount of records that fit your query-predicate (and not in the records themselves), you shouldn't SELECT * but SELECT Count(*) , then fetch the query result like you already do in other parts of your code, with fetch() or fetchAll() and then read from the returned array:
http://php.net/manual/en/pdostatement.fetchall.php[^]

Edit: formatting

Posted 7-Apr-15 18:34pm

Sascha Lefèvre

Updated 8-Apr-15 2:20am

v2

Comments

jba1991 8-Apr-15 9:13am

I see! So because it returned true or false it means there was only 1 record which is why the count was saying there was > 0 records, even though (i thought) there wasnt!

Does that mean something like this should work:

$success = $output->execute();
if ($success){
$results = $output->fetchAll();
if (count($results) > 0){
$msg = '<li>My Messages (new)</li>';
} else {
$msg = '<li>My Messages</li>';
}
}

Sascha Lefèvre 8-Apr-15 9:18am

Yes, that should work

jba1991 9-Apr-15 7:41am

Its doing the same as before :(

Sascha Lefèvre 9-Apr-15 8:20am

You mean it always displays "(new)" ?

jba1991 9-Apr-15 10:43am

Yeah. Unless I change it to > 1 instead of > 0. And even if there are records that should be returned, when using > 1, it doesnt show as (new).

Sascha Lefèvre 9-Apr-15 10:55am

Please insert this line after the fetchAll()-line:
var_dump($results);

Maybe the output can give you/us a clue.

jba1991 9-Apr-15 11:40am

array (size=1)
0=>
array (size=2)
'COUNT(*)' => string '0' (length=1)
0 => string '0' (length=1)

Sascha Lefèvre 9-Apr-15 11:47am

Sorry, I should have written that in my previous comment already: Please run that twice - once with a query that should show "new" messages and once with a query that should not. Please show the output for both then.

jba1991 9-Apr-15 16:15pm

it returns the same results for:
count > 0
count > 1
count < 1

Sascha Lefèvre 9-Apr-15 17:17pm

Hmm.. curious. I don't see the error atm. Please try something different:

$query = 'SELECT Count(*) AS UnreadCount FROM messages WHERE messageTo = :to AND messageRead = 0';

Then the whole shabang like you already do in other places where you select something, and then read 'UnreadCount' from the result and compare that to 0.

jba1991 10-Apr-15 8:40am

Ive tried that and im getting an undefined index. I must be missing some syntax or something?

$db = Database::getConnection();
$query = 'SELECT Count(*) AS UnreadCount FROM messages WHERE messageTo = :to AND messageRead = 0';
$output = $db->prepare($query);
$output->bindParam(':to', $s_username);
$success = $output->execute();
if ($success){
$results = $output->fetchAll();
$unreads = $results['UnreadCount'];
if (count($unreads) > 0){

the undefined index is on the line where I assign UnreadCount to $unreads

Sascha Lefèvre 10-Apr-15 9:38am

Please try:
$results = $output->fetchAll(PDO::FETCH_ASSOC);
And after this line:
$unreads = $results['UnreadCount'];
$unreads already contains the amount of found records (and is no array), so instead of
if (count($unreads) > 0)
you use it like this:
if ($unreads > 0)

(Regarding the SQL_CALC_FOUND_ROWS-thing from your other question: I have to setup MySQL/PHP first, so I can't do it just so - I'll try to get it done over the weekend.)

jba1991 10-Apr-15 9:43am

I made them changes but its still saying the same thing about an undefined index for UnreadCount

Sascha Lefèvre 10-Apr-15 9:47am

Please insert
var_dump($results);
again, after the fetchAll()-line

jba1991 10-Apr-15 9:52am

array (size=1)
0 =>
array (size=1)
'UnreadCount' => string '0' (length=1)

What is var_dump? some kind of debugging?

Sascha Lefèvre 10-Apr-15 9:55am

Yes, dumps (prints) all the contents, especially useful for arrays.

I think I got it now.. please try this:

$unreads = $results[0]['UnreadCount'];

jba1991 10-Apr-15 10:03am

Yes! Good job man, thanks. Why did you have to include[0]? thats something to do with the first array result isnt it?

Sascha Lefèvre 10-Apr-15 10:14am

Yes - $results is an array of arrays. The reason why you don't have to do this (the first "indexer" [0]) when listing multiple records is because the foreach-loop breaks that array of arrays down into one simple array "at a time" for you inside the loop. I could have thought of that earlier and spared you some tries but somehow I overlooked that, sorry. Please accept my answer :-)

Sascha Lefèvre 10-Apr-15 10:56am

Good luck with your project!