[RESOLVED] Adding keys to an array

Master_Zen

Hello,

Here's the situation:

I have an array from a mySQL query. The array will have 9 keys and a number of values depending on the results of the search. However, I want to add 2 new keys to this array.

The 1st new key is a number, starting with 1 with the first value and auto-incrementing with each new row.

The 2nd new key is a function of another existing key.

To illustrate this, imagine the following array:

$array['NAME'] = John, Mark, Roger
$array['AGE'] = 25,28,31
$array['STATE'] = DC,NY,MA

new array:

$array['NAME'] = John, Mark, Roger
$array['AGE'] = 25,28,31
$array['STATE'] = DC,NY,MA
$array['ORDER'] = 1,2,3
$array['AGEPLUS5'] = 30,33,36

My first idea was to make a while() loop and simply add the keys like this:

$a = 0;
while ($array = mysql_fetch_array($mysqldata)) {
	$a++;
	$array['ORDER'] = $a;
	$array['AGEPLUS'] = $array['AGE'] + 5;
}

Doesn't work though :queasy:

Suggestions?

Installer

I'm going to take a leap and guess, from what you say, that your original data, in array, would look not like this:

$array['NAME'] = John, Mark, Roger
$array['AGE'] = 25,28,31
$array['STATE'] = DC,NY,MA

but like this:

$array[0]['NAME'] = John
$array[0]['AGE'] = 25
$array[0]['STATE'] = DC
$array[1]['NAME'] = Mark
$array[1]['AGE'] = 28
$array[1]['STATE'] = NY
$array[2]['NAME'] = Roger
$array[2]['AGE'] = 31
$array[2]['STATE'] = MA

You could add elements like this:

$a = 0; 
while ($row = mysql_fetch_array($mysqldata)) { 
    $array[$a] = $row;
    $array[$a]['ORDER'] = $a; 
    $array[$a]['AGEPLUS'] = $array['AGE'] + 5; 
    $a++; 
}

Or do it with MySQL queries:

mysql_query("SET @a = -1");
$query = "SELECT NAME, AGE, STATE, @a := @a + 1 AS ORDER, AGE + 5 AS AGEPLUS FROM my_table";
$result = mysql_query($query);
$num_rows = mysql_num_rows($result);
for ($i = 0; $i < $num_rows; $i++) { 
    $array[$i] = $row;
}

Thats' untested, so use the MySQL manual.

Master_Zen

You are right, it is more like that. I'm going to test the first code to see if it works.

Installer

It should, if you make this correction. Change

$array[$a]['AGEPLUS'] = $array['AGE'] + 5;

$array[$a]['AGEPLUS'] = $row['AGE'] + 5;

My error.

Master_Zen

Btw, let me understand something, when you write this:

while ($row = mysql_fetch_array($mysqldata)) { 
    $array[$a] = $row;

that means you are dumping the old array ($row) into a new array ($array)?

Also, how would I print this, using foreach() ?

Installer

...dumping the old array ($row) into a new array ($array)?

Not exactly. In each iteration of the while loop we are putting one row at a time, as an array, of the query results into $array[$a]. When the while loop finishes, $array will be a two-dimensional array, the second dimension holding all the row data returned by the query plus the two added elements.

To see the structure and data of the completed array, add this at the end:

foreach ($array as $key => $value) {
    echo $key . '<br />';    

    foreach ($value as $key_2 => $value_2) {
        echo $key_2 . ' => ' . $value_2 . '<br />';
     }
}

or:

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

Master_Zen

I get double results. I'm testing this in action on a query which gets you 1 match and I get the results as follows:

0 => John
NAME => John
1 => 25
AGE => 25
2 => DC
STATE => DC

Interestingly, for the two new values I get them correctly

ORDER => 0
AGEPLUS5 => 30

Sorry if I'm asking stupid questions, I've always had a lot of trouble with arrays

Master_Zen

Seems to work if I add MYSQL_ASSOC inside mysql_fetch_array()

Still testing...

bradgrafelman

That's because [man]mysql_fetch_array/man, without a second parameter, returns both a numerical and an associative array. Since I only ever deal with associative arrays (as you are trying to, here), I always use the [man]mysql_fetch_assoc/man function.

Master_Zen

Well, it appears this issue is resolved. I might have more difficulties as my code is not yet finished but they will be unrelated to adding keys to arrays. Thank you everyone especially Installer. 🙂