Need A Little Help With Some Php Mysql Functions

[samporras]

Hi guys.

 

I'm still relatively new to php programming and I'm having some problems with some functionality that i am currently writing. I want to capture all the data from my database table and put it in a 2 dimensional array. I found this function online that seems to do the trick:

 

>function mysql_fetch_data($result, $numass=MYSQL_BOTH) {
$i=0;
$keys=array_keys(mysql_fetch_array($result, $numass));
mysql_data_seek($result, 0);
while ($row = mysql_fetch_array($result, $numass)) {
	foreach ($keys as $speckey) {
		$got[$i][$speckey]=$row[$speckey];
	}
	$i++;
}
return $got;
}

 

the problem i am having is that i want to reference each element within the master array dynamically:

 

>	$result = mysql_query($select, $conn) or die(mysql_error());
$rowcount = mysql_num_rows($result);
$properties = mysql_fetch_data($result);

for($i=1; $i<10; $i++)
{			
	if($rowcount <= $i)
	{
		echo('filename: '.$properties[$i]['filename'].'<br />');
	}
	else
	{
				   //do something else
	}
}

 

why is it that i can not reference that specific index position dynamically? when i replace my variable ($i) with a specific value, the correct value for my field 'filename' is appearing. am i missing something or doing something incorrectly?? any help would be greatly appreciated!

 

 

Thanks in advance,

 

Sam

[OJB]

The first thing I notice is the for loop. You are first starting from element 1 in the array ($i = 1) but PHP arrays start from 0. So change that to $i = 0;

 

Secondly you are looping through the data 9 times but you should be looping through while $i is LESS than $rowcount. So change that to $i <$rowcount;

 

Then inside the loop you are checking to see if $rowcount is LESS that or equal to $i. I don't get what you are trying to do, surely you would want it the other way around otherwise the data you are seeking in the array will not exist.

 

Personally I would change your for-loop to:

 

>for($i=0; $i<$rowcount; $i++)
{			
	  echo 'filename: '.$properties[$i]['filename'].'<br />';
}

 

No need for the check against row count because the for loop does that

No need for the else statement because it won't be in the loop under those circumstances.

 

 

I can't see a reason why that would not work off the top of my head.

 

 

Hope this helps.

[samporras]

Personally I would change your for-loop to:

 

>for($i=0; $i<$rowcount; $i++)
{			
	  echo 'filename: '.$properties[$i]['filename'].'<br />';
}

 

Thanks for the help OBJ. I didn't know that in PHP the start is 0 so i've updated my for statement.

 

I didn't post the entire piece of code. The reason I was looping through 10 times is because i wanted to do something from 0 to rowcownt, and then do something else from rowcount to 10. The problem i'm having is when executing the following statement:

 

>echo 'filename: '.$properties[$i]['filename'].'<br />';

 

The result i get is just

filename:

 

when i remove $i from the index reference, the correct value shows up for the filename variable. (ie. $properties[1]['filename'])

[OJB]

Hello, OK I think I understand what you were trying to do now.

 

 

At the top of your PHP file just under the <?php can you paste this line of code:

 

>error_reporting(E_ALL);

 

 

This will print any errors that occur during the script in the browser as you test the script.

 

I still think there is an error in the logic... I would change your for loop to this:

 

> for($i=0; $i<10; $i++)
{			
	if($rowcount > $i)
	{
		echo('filename: '.$properties[$i]['filename'].'<br />');
	}
	else
	{
				   //do something else
	}
}

 

The only thing I have changed is: $rowcount > $i.

 

What you were doing before is cycling through your results, then checking if $rowcount was LESS than or equal to the current value of $i. This wouldn't work and is probably the reason you are getting the output of just "filename:"

 

I shall explain why now:

 

Let's say for an example that your MySQL query returns 5 rows.

 

$rowcount therefore = 5.

 

then you start at $i = 0

 

$i =0 , $rowcount <= $i, (5 <= 0) ... FALSE...

$i =1 , $rowcount <= $i, (5 <= 1) ... FALSE...

$i =2 , $rowcount <= $i, (5 <= 2) ... FALSE...

 

....

$i = 5 , $rowcount <= $i, (5 <= 5) ... TRUE... So now we have one that is true. But as there are only 5 rows returned there will be NO value for $properties[5]['filename'], as PHP arrays begin from 0 the $properties[5] is actually the 6th element, hence no result, hence "filename: " So from then on $i =6 to $i=9 is the same result.

 

 

This I think should solve your issue.

[samporras]

you are absolutely right. my logic was wrong. i guess that's what i get for writing code at 2am

 

your suggestion has fixed my issue. thank you very much for your help!

 

Sam

[OJB]

No problem, Sam.

 

Good luck with it and feel free to ask anything else