How to change array values

Anon

I am reading an array of dates off of a MYSQL database.

$r1 array();
while($row = mysql_fetch_array($result))
{
$r1[] = date('M', $row["Date"]);
}
$a = array($r1);

how would I rewrite this in order for duplicated values to be changed to NULL.

for example, say my array retrieved from my database is
array(jan, jan, jan, feb, feb, feb, mar, mar, mar,...)

How can I get it to look like
array(jan, null, null, feb, null, null, mar, null, null...)

thanx

alec_php

You can use the GROUP BY feature in your SQL query, like this, no more PHP coding is needed.

inter_joe

some ideas:

1.

use the DISTINCT keyword in your sql-query to eliminate duplicate rows:
SELECT DISTINCT Date FROM yourTable ....
btw.: you should change the row-name 'Date' to something different, if you can. it causes no problems in MySQL but other db's don't like that, because it's a type like 'text', 'blob' etc.

2.

use array_count_values(). see:
http://www.php.net/manual/en/function.array-count-values.php

$a = array("jan", "jan", "feb", "feb", "feb", "mar");
$b = array_count_values($a);

$b is now array("jan" => 2, "feb" => 3, "mar" => 1)

3.

try this:
$a = array("jan", "jan", "feb", "feb", "feb", "mar");
$b = array();
foreach ($a as $m) $b[$m] = $m;

$b is now array("jan" => "jan", "feb" => "feb", "mar" => "mar")

4.

$a = array("jan", "jan", "feb", "feb", "feb", "mar");
$b = array();

foreach ($a as $m)
$b[] = (!in_array($m, $b) ? $m : FALSE);

$b is now array("jan", , "feb", , , "mar");

hope that helps
joe