Array of arrays, and adding a field to it...

TheJuice

If I have this:
$output = array( 'id' => $row['id'], 'name' => $row['name'] );

Afterward, if I want to add a new associative field in this array, I would do like that:
$output['new_field'] = $variable.

this is clear, there's no problem.

BUT...

If I have this (an array of arrays):
$output[] = array( 'id' => $row['id'], 'name' => $row['name'] );
Then how can I add a new associative field ???
Because if I do $output['new_field']=... I'll lose all my previous values.
And I can't do $output[]['newfield'] either, as it will add an element with only 'new_field' in it...

Thanks for your help,
Philippe.

tomhath

$output[] = array( 'id' => $row['id'], 'name' => $row['name'] );

Take a deep breath and think about what you are doing here. The $output array now contains an array element (which is an array, but that's not anything special). But how can you refer to that array element?

You didn't give it a key, so you can't refer to it as an associative array. But it ("it" being the array that is an element of the $output array) must still have an index like any other array element. So you have to index into $output to get the element that's an array. See if this works:

$output[0] ['new_field'] = 'Some Value';

TheJuice

The problem is that I am in a loop, so $output[0] would work only with the first element...

So the solution I am using right now (and which works), is that I don't let PHP automatically increment the keys, and provide it with a key I increment myself:

$i = 0;
while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
$output[$i] = array( 'id' => $row['id'],
'name' => $row['name'] );

$output[$i]['contract_id'] = $details_contract['id'];
$output[$i]['contract_name'] = $details_contract['name'];
$i++;

}

Don't ask why I didn't simply add the fields in when I first create the variable, because I stripped some of the code...

So this works, but I'd find it simpler to let PHP auto-increment the keys, and use something like
$output[$PHP_LAST_INCREMENT]['contract_id'] = ...

devinemke

what your basically trying to do is create a multi-dimensional array from your result set, right?

while ($row = mysql_fetch_assoc ($result))
{
extract ($row);
$result_array[$id] = $row;
}

you now have $result_array which is a 2D array with the "id" field as the key (ideal since it is probably auto_incrementing) and the entire contents of the row as an associtaive array as the value.

Weedpacket

An alternative formulation to TheJuice's code (which would be cleaner if it used mysql_num_rows() and a for loop instead) would be to put together the entire row first, and only when it's complete add it to the output array:

while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
    $outputrow = array( 'id' => $row['id'],
                                     'name' => $row['name'] );

$outputrow['contract_id'] = $details_contract['id'];
$outputrow['contract_name'] = $details_contract['name'];
$output[]=$outputrow;
}

Weedpacket

Originally posted by devinemke
what your basically trying to do is create a multi-dimensional array from your result set, right?
extract ($row);
[/b]

If you don't mind a potentially toxic namespace leak of new variables with names like $id and $name and who knows what else those table fields might be called swarming out and maybe stomping over anything else that already have those names.

philipolson

In which case either unset them afterwards or use extracts second optional parameter (such as a prefix).

TheJuice

Thanks Weedpacket
I'll do like you advised, namely to put it in a temporary variable, and then put it into the output variable.
That should be the best I think.