How to dynamically generate Excel column numbers in php? - php

Question

I'm writing an export to excel & have a dynamic number of columns, i.e. I won't know how many columns will be needed before I run the query so I need to dynamically assign the column numbers like below:
$objPHPExcel->setActiveSheetIndex(0)
->setCellValue('A1', 'value')
->setCellValue('A2', 'value')
->setCellValue('B2', 'value')
->setCellValue('C2', 'value')
//...etc...
->setCellValue('AA2', 'value')
->setCellValue('AB2', 'value')
->setCellValue('AC2', 'value')
//...etc...
how can I do this with php?
UPDATE
sorry, the column naming pattern is:
A, B, C, .. AA, AB, AC ... BA, BB, BC... etc, the number suffix is actually the row. and no, the 'value would actually be populated from some query data setting my values would look more like:
$i=1;
while($result= $query->fetch_assoc()){
->setCellValue($col.$i, $result['whatever'])
$i++;
}
I just don't know how to get the column letters to increment in that pattern.

Answer 1

Simplest answer is
use PhpOffice\PhpSpreadsheet\Cell\Coordinate;
echo Coordinate::stringFromColumnIndex(5) // return E
echo Coordinate::columnIndexFromString('AA') // returns 27

Answer 2

Optimized Function
function columnFromIndex($number){
if($number === 0)
return "A";
$name='';
while($number>0){
$name=chr(65+$number%26).$name;
$number=intval($number/26)-1;
if($number === 0){
$name="A".$name;
break;
}
}
return $name;
}

Answer 3

If you don't know how many columns/rows you're going to be working with in advance, how can you expect to use the fluent interface in this way?
Following your edit of the question, you might do something like:
$i = 1;
while($result = $query->fetch_assoc()){
$col = 'A';
foreach($result as $value) {
$objPHPExcel->getActiveSheet()->setCellValue($col++.$i, $value);
}
$i++;
}
However, you might consider taking another approach, and using the fromArray() method to populate your data
$i = 1;
while($result = $query->fetch_assoc()){
$objPHPExcel->getActiveSheet()->fromArray('A'.$i++, $result);
}

Answer 4

Maybe so late, and i dont know if there's a better solution but, i make this recursive function to solve this problem
private function getLastColumn($last){ //last represent how mouch X axis spaces
//you want to jump
$max = 26; //Max characters (in number) that you cant jump, ('z´)
$inicial = 'A';
$col = '';
if ($last > $max) //if last is bigger than last you should recall the function
{
$last = $last - $max; //discount the max to the last
$letterAscii = ord($inicial); //tansform the charcter to to number
$letterAscii += ($last - 1); // add last -1(-1 to stay in A to keep the
//base 1)
$col = chr($letterAscii); // int to ascci
$col = $col.$this->getLastColumn($last); // recall the funcion and concat
//the result
}else{
$letterAscii = ord($inicial); // same as adove
$letterAscii += ($last - 1);
$col = chr($letterAscii); //only pass the result to col
}
return $col; //return coll
}
and with this if you need 27 spaces to de right you will get 'AA'
if there is a better solution teld me :)

Answer 5

i think is too late, but for my snippet
i make this function,
function number_to_column($num) {
$column_name = array();
for($i=0;$i<=$num;$i++) {
$numeric = $i % 26;
$letter = chr(65 + $numeric);
$num2 = intval($num / 26);
if ($num2 > 0) {
if($i<26) {
$v_column = $letter;
}
if($i>25 && $i<52) {
$v_column = 'A'.$letter;
}
if($i>51) {
$v_column = 'B'.$letter;
}
$column_name[] = $v_column;
} else {
$v_column = $letter;
$column_name[] = $v_column;
}
}
return $column_name;
}
then we can use it like this
$column_name = number_to_column(count($array[0])-1);
the $column_name will result excel row name,