Hi,

I took the content of a query on my database, and threw it into an array, this way

$tabData = array ();
while ($lineData = mysql_fetch_assoc ($resultSql))
{
  array_push ($tabData, $lineData);
}

So, each line is an associative array containing several columns.
I want to sort this array line by line, depending on the content of columns (example : sort lines on column title, ascending then on column date descending), but array_multisort doesn't seem to be acting this way.

Could someone help, please ?

Decision #1: Use mysql sorting. E.g. select * from my_table order by title asc, date desc
Decision #2: Use usort(). This function is well described in PHP manual. The "cmp" function will look like this:

PHP Code:

    function sortByCountryPlant($a, $b) {
        $a->country = $a->countries[0]->country;
        $a->plant = $a->countries[0]->plant;

        $b->country = $b->countries[0]->country;
        $b->plant = $b->countries[0]->plant;

        if ($a->cid == $b->cid) {
            if ($a->sid == $b->sid) {
                if ($a->country == $b->country) {
                    if ($a->plant == $b->plant) {
                        if ($a->name == $b->name) {
                            return 0;
                        }
                        else
                            return ($a->name < $b->name ? -1 : 1);
                    }
                    else
                        return ($a->plant < $b->plant ? -1 : 1);
                }
                else
                    return ($a->country < $b->country ? -1 : 1);
            }
            else
                return ($a->sid < $b->sid ? -1 : 1);
        }
        else
            return ($a->cid < $b->cid ? -1 : 1);
    } 


It is just an example of how to sort array of objects by multiple fields, but in your case you may redesidn the function to sort array of arrays (which is in fact much similar to array of objects).

Also please note that while sorting on multiple fields the (N+1)'th sorting field is only used to sort the subset of records when values of the N'th sorting field is are the same for some records. In your case records will be sorted by title first and if some titles are same then they will be sorted by date. Only so, not less, not more.

Thanks a lot
I'm gonna have a look at usort, 'cause mysql sorting here is ... irrelevant

Aaaaaaaaaaaarrrghhhh !!!
It seems usort doesn't work properly if the array is an object attribute.

Why don't you want to use mysql_fetch_object() instead of mysql_fetch_assoc() ?

If you only want to produce one table of data, with each dataset presented only once and ordered as you specify, I don't see why you cannot use mysql sort as mtishetsky suggests in his first reply.

A little more information on your table structure, your query string and what you actually want to achieve would be helpful.

Regards

Ian

I sort in in the query, but I want to be able to sort it in php too, 'cause i' have to sort the same resultset different ways.
So several queries would be absurd.

NB : the mysql_fetch_anything method is not the problem here

When you display something you use one query. If a user clicks some button or link labelled like "Show me the same items but ordered by another field" then you have to reload a page anyway and call another query. Write a function like following and just call it with neccessary parameter:

PHP Code:

function getTitles($orderby = "") {

   $sql = "select * from table ";
      if ($orderby != "")
         $sql .= " order by $orderby ";
   $result = mysql_query($sql);
   ...
   return $records;
} 


I hope you don't display the same set of records twice on the same page, first ordered by title and second ordered by date.

Originally Posted by mtishetsky

I hope you don't display the same set of records twice on the same page, first ordered by title and second ordered by date.

No, but i re-use the same set of data, using it differently.
I think i'm gonna have two queries : that will be far more simple, and on this size of data, after all, it's not so bad.
Perhaps i'm too purist sometimes