Thread: php wont recognize array

i just started designing a website, and most of it requires php to run.
i have a problem with an array which php isn't recognizing. the array is pulled from a database, so i just put the variable as an array. which doesn't seem to work.
my code will probably explain better.

PHP Code:

<?php
    phpif (isset($_GET['bid'])) {
        $DPView = "";
        $detailPhotoView = "";
        $targetID = $_GET['bid'];
        $Bsql = mysql_query("SELECT * FROM builds WHERE id = $targetID");
        while ($row = mysql_fetch_array($Bsql)){
            $DP = $row["photo"];
            $DetailPs = $row["detail_photos"];
            $DetailPA = array($DetailPs);
            $DPsql = mysql_query("SELECT * FROM photos WHERE id = $DP");
            $DPD = mysql_result($DPsql,0,'details');
            foreach ($DetailPA as $DetailP){
                $DetailP = $DetailP;
                $DetPsql = mysql_query("SELECT * FROM photos WHERE id = $DetailP");
                while ($row = mysql_fetch_array($DetPsql)){
                    $DetailPD = $row["details"];
                    $detailPhotoView .='
                        <div id="listItem">
                            <div style="float:left; width:210px; height:179px" class="left">
                                <div style="height:160px"><img src="http://webprocafe.com/db_images/'.$DetailP.'.jpg" width="200" /></div>
                                <div height:19px align="right">Delete | Submit</div>
                            </div>
                            <div style="float:left; width:10px">&nbsp;</div>
                            <div style="float:left; width:695px; height:179px" id="detail">Details:<br />
                                <textarea name="details" id="details" cols="70" rows="8">'.$DetailPD.'</textarea>
                            </div>
                        </div>';
                }
            }

            $DPView .= '
                <div id="listItem">
                    <div style="float:left; width:210px; height:179px" class="left">
                        <div style="height:160px">
                            <img src="http://webprocafe.com/db_images/'.$DP.'.jpg" width="200" style="align="center; vertical-align:middle" />
                        </div>
                        <div height:19px align="right">Delete | Submit</div>
                    </div>
                    <div style="float:left; width:10px">&nbsp;</div>
                    <div style="float:left; width:695px; height:179px" id="detail">Details:<br />
                        <textarea name="details" id="details" cols="70" rows="8">'.$DPD.'</textarea>
                    </div>
                </div>';
        }

    }
?>

$detailPhotoView and $DPview are just what is posted into the body of the website.
the array is $DetailPA, for the array ive put $DeatilPs which is data from a database. if i just put number instead of $DetailPs it semms to work properly, but with the variable it doesnt seem to explode the data to get each individual number.
any ideas?
thanks

When debugging your code, you often need to inspect the values of variables. Sometimes they are not what you think they should be. Use the following code to do this:

Code:

<?php var_dump($myVariable); ?>

So have a look at your arrays. Check that they are actually arrays, and that they contain the data you expected.

Before inserting arrays into databases, you need to use PHP's serialize($array) function. And when you extract the array from the database, you need to use unserialize($array) to convert it back into a PHP array.

i tried showing the variable and its showing it as an array. it shows variables.PNG
i think thats what they should be, unless they shouldn't have the ' on each end of the array.
how would i use the unserialize function, ive never used it before?
thanks

Oh, I think I understand what's happening.

$detailPs is what came from the database. This is a string, not an array. You then tried to turn this into an array, $DetailPA.

Technically you succeeded, but I don't think you got the result you wanted. $DetailPA is an array with only one key, which has the value '3,1,7' -- which is just a string of characters (like a word).

I think you wanted this:

Code:

$DetailPA =
array
[0] => 3
[1] => 1
[2] => 7

Is that right?

yeh thats right.
do i need to change the field type in my database to an int value?

yeh thats right.
do i need to change the field type in my database to an int value?

Originally Posted by homer93

No, that won't help. At best you'll get an error; at worst, it will mangle your string by forcibly converting it to an integer (maybe the result would be 3, or 317, or even 0 or 1).

Do you control the code that inserts this into the database? If so, the neatest option would be to serialize() the array before you insert it, and then unserialize() the array when you extract it.

Otherwise, you'll need to convert the string into an array:

Code:

$DetailPA = explode(",", $detailPs);

That will produce an array like this:

Code:

$DetailPA = 
array
[0] => '3'
[1] => '1'
[2] => '7'

Note these are strings, not numbers. This is probably okay, because in most cases PHP will work out what you intend (PHP is weakly typed). But if you need them to be numbers, you can typecast them:

Code:

foreach ($DetailPA as &$value) {
settype($value, "integer");
}
unset($value);

PHP Code:

$DetailPA = explode(',',$DetailPA[0]); 


Do you control the code that inserts this into the database? If so, the neatest option would be to serialize() the array before you insert it, and then unserialize() the array when you extract it.

Originally Posted by Mike Hopley

in most cases, serializing stuff & dumping it in the database is not cool. It decreases "code" readibility ('1,3,7' is easier to read than 'a:3:{i:0;i:1;i:1;i:3;i:2;i:7;}') and also takes up more storage space. Also takes more performance to serialize/unserialize than insert a comma-seperated string and explode it after selecting. Problems like this can usually be solved in a better fashion (in this case, re-think your database schema). There are exceptions, especially when optimizing performance, but in general not good practice

in most cases, serializing stuff & dumping it in the database is not cool. It decreases "code" readibility ('1,3,7' is easier to read than 'a:3:{i:0;i:1;i:1;i:3;i:2;i:7;}') and can usually be solved in a better fashion (in this case, re-think your database schema). There are exceptions, especially when optimizing performance, but in general not good practice

Originally Posted by janvt

Readability is only an issue if you actually want to look at this "code" directly in the database.

I'm very willing to be educated here, but can you point me towards some resources explaining why serialising is "bad practice"?

got it
i used

PHP Code:

$DetailPA = explode(',',$DetailPs); 


at the moment i havnt made the form for adding the array/string to the database. thats my next task.
thanks for the help