有人可以澄清未设置（$ row ['something']）？

Question

I would like to have this peace of code clarified:

unset($row['something']);

Because in my code, I use this to delete a number of columns from my results that I get from a query. I'm using this to get the array and walk through it:

$rows = array();
while($row = $result->fetch_assoc())

I need the columns to make other combined columns. Later when I try to do an export to csv file it is still showing the unset columns. Which should have been deleted using unset. So in the while I use the unset method to delete a couple of columns.

Really hope someone can help me with this because I don't know how to delete these columns from my array.

UPDATE:

public function getRows()
{
    global $global_db_link;
    $result = $global_db_link->query($this->getQuery());

    $rows = array();
    while($row = $result->fetch_assoc())
    {
    // This is where i use different columns to calculate something 
    // and make a new column out of it
        unset($row['column_header']);       
        $rows[] = $row;
    }
return $rows;

So this is it in a short version.

Answer 1

Unset can be used to remove information from am array of information, as you say above. However $row in your while loop is fetching information from your database. Why would you ever need to unset specific rows? I'm not even sure if that is possible.

You would be better off building a second array that excludes the specified columns for your export to CSV.