[RESOLVED] Fill a multidimensional array?

[nawrik]

Hi,

I'm struggling to get my head around this problem. All help, as usual greatly appreciated.

I want the array to look like this:

$gallery = array(
0 => array("location" => "images/001.jpg", "title" => "Image Title 1", "description" => "Image description number one"),
1 => array("location" => "images/002.jpg", "title" => "Image Title 2", "description" => "Image description number two")
);

This successfully allows me to use a foreach statement to blast through the images in the array:

foreach ($gallery as $image)
printf ("Title: %s Description: %s<br />", $image[title],$image[description]);
}

This seems to be working fine when the array is filled in manually.

However the problem comes when I try to load the array using information from a database.

I can't seem to figure out the correct syntax to populate a multidimensional array from a MySQL database.

Any ideas??

All help appreciated.

[dagon]

the basics of the approach:

while(){
$gallery[]=array("location" => "??" ...);
}

[nawrik]

Dagon,

thank you for your reply.

I'm one step closer to solving this, I know it's simple - I just don't fully understand the 'expression' part of the WHILE statement - therefore I'm not sure if i'm using it correctly.

Also I don't fully understand how to pull the info from the db?

Here is what I have so far (and many, many variants):

$query = "SELECT * FROM images";
$result = mysql_query($query) or die('Query failed: ' . mysql_error());
$id = mysql_result ( $result, 0, "id" );
$title = mysql_result ( $result, 0, "title" );
$location = mysql_result ( $result, 0, "location" );
$description = mysql_result ( $result, 0, "description" );

$num=mysql_numrows($result);

while($row = mysql_fetch_row($result)){
$gallery[]=array("location" => $location,"title" => $title,"description" => $description);
} 

print_r($gallery);

Array ( [0] => Array ( [location] => images/01.png [title] => Title 01 [description] => Description of image 01 ) [1] => Array ( [location] => images/01.png [title] => Title 01 [description] => Description of image 01 ) ) 

The layout of the array seems perfect (I think?) However because I'm not understanding the use of mysql_* functions the WHILE statement - I'm running around in circles?

I know I'm close, I also really enjoy solving these problems 'myself' so appreciate the vague replies - they help my learning!!

[rincewind456]

In your snippet you're using two different methods of getting the results from the same dataset, something that is not recommended.

[man]mysql_result()[/man] gets one cell of the dataset at a time and is slow (check the manual page).

[man]mysql_fetch_row()[/man] on the other hand fetchs an entire row of the dataset, quicker.

If you just wanted to fetch the first row of a result set (unlikely) the

$row = mysql_fetch_row($result);

would do it.

The [man]while()[/man] loop loops through the result set until there are no more results, so

 while($row = mysql_fetch_row($result)){
	$gallery[] =$row;
}

would create an array of the entire result set.

But what think you are trying to achieve would be best done with [man]mysql_fetch_assoc()[/man] so that by doing this

while($row = mysql_fetch_assoc($result)){
	$gallery[] =$row;
}

you would get this type of result

Array ( [0] => Array ( [location] => images/01.png 
			[title] => Title 01 					
			[description] => Description of image 01 ) 
	[1] => Array ( [location] => images/01.png 
			[title] => Title 01 
			[description] => Description of image 01 ) )

A tip to better see the structure of your arrays is to enclose them in <pre></pre> tags like this

echo '<pre>';
print_r($gallery);
echo '</pre>';

[nawrik]

rincewind,

I have been slogging away at trying to get this done, thought I was getting there - but I seemed to be going a VERY long way around.

Until your post I didn't realise the array was automatically filled (I was trying to fill with each variable).

Thanks for the <pre> tip

Makes the array much more pleasing to the eye!

So thanks to your genius, my code looks like this:

$result = mysql_query($query) or die('Query failed: ' . mysql_error());

while($row = mysql_fetch_assoc($result)){
    $gallery[] =$row;
} 

echo '<pre>';
print_r($gallery);
echo '</pre>';

What's brilliant about this is the $gallery array can be print_r OUTSIDE of the loop, something I was having trouble with before your code simplified the whole process!

Now, the next question:

I was hoping to print the individual data from each array 'component' as and when I needed it - I do go about doing this?

My first instinct:

echo $gallery[1][title];

Doesn't work - it just prints 'Array'??

Any ideas?

[rincewind456]

Yes the way your doing it is by printing off the results from inside the while loop. But at the same time you're creating an array in $gallery, so you could build up the code for your images into another variable like so

while($image = mysql_fetch_array($result)){
$display .= '<img src="'.$image['location'].'" /><br />'.$image['title'].'<br />'.$image['description']."<br />\n";
}

and then just echo out $display where you want it to appear in the code.
Or you could use the [man]mysql_fetch_assoc()[/man], I assume your column names in your database are id, location, title and description. If they are then using

while($row = mysql_fetch_assoc($result)){
	$gallery[] =$row;
}

will do the exact same thing as your doing with this

$gallery = array($image["id"] => array("location" => $image["location"],"title" => $image["title"],"description" => $image["description"]));

You could then use a [man]for()[/man] loop to loop through the varaible $gallery and build up your html code.

To me it is obviously easier an faster to do it this way

while($row = mysql_fetch_assoc($result)){
$display .= '<img src="'.$image['location'].'" /><br />'.$image['title'].'<br />'.$image['description']."<br />\n";
}

as your only getting the associative array rather than the associative and numeric.

[nawrik]

Rincewind,

thank you for all your help.

I actually edited my post (most likely when you were replying).

I basically accepted that your way was much swifter and ditched my long winded attempt at creating an array.

I then went on to say:

Now, the next question:

I was hoping to print the individual data from each array 'component' as and when I needed it - I do go about doing this?

My first instinct:

echo $gallery[1][title];
Doesn't work - it just prints 'Array'??

Any ideas?

[rincewind456]

If you use the associative array then

print $gallery[1]['title']; 

would do it, you should have the single quotes around the name otherwise the parser look for a constant.

[nawrik]

Works a treat!

Thank you.

So for future reference of those searching:

To create a Multidimension Array using data from a MySQL Database.

//Create Query
$query = "SELECT * FROM images";
//Store query in $Result
$result = mysql_query($query) or die('Query failed: ' . mysql_error());
// Use WHILE and mysql_fetch_assoc to loop through each row.
while($row = mysql_fetch_assoc($result)){
    $gallery[] =$row;
} 

This will create the array:

Array
(
    [0] => Array
        (
            [id] => 1
            [location] => images/01.png
            [title] => Title 01
            [description] => Description of image 01
        )

[1] => Array
    (
        [id] => 2
        [location] => images/02.png
        [title] => Title 02
        [description] => Description of image 02
    )

)

To view this array as above, use:

echo '<pre>';
print_r($gallery);
echo '</pre>';

If you want to use individual elements of the array use:

 print $gallery[1]['title']; 

Replacing '1' with your row ID and 'title' with your Column Title.