PHP SQL除以零警告，但不为零

Question

I have a trouble. I have a SQL table with processes which are finalized, closed, cancelled and working on, which also are associateds by an area (talent, outsourcing, digital, etc). I want to do an AVG by the area and total by the states of the processes. so i have:

$tiempoQueryFinalizados = mysqli_query($con,
 "SELECT IFNULL(SUM(IFNULL(timestampdiff(DAY,fecha_creacion,IFNULL(fecha_cerrado,NOW())),0)),0) AS finalizados, 
    (Select count(id_proceso) from proceso where estado ='FINALIZADO' and fecha_cerrado is not null) as c 
  FROM proceso 
  WHERE estado = 'FINALIZADO' and fecha_cerrado IS NOT NULL and area ='".$rowArea['id_area']."' ");

Then I use a simple division in PHP with

mysqli_fetch_assoc($tiempoQueryFinalizados)['finalizados'] / mysqli_fetch_assoc($tiempoQueryFinalizados)['c']

but I get the error Warning: Division by zero , so I check if was zero but it doesn't. In this example mysqli_fetch_assoc($tiempoQueryFinalizados)['c'] = 2 but still counting as 0

any help, please?

EDIT: the area is returned by a fetch array of $areaQuery = mysqli_query($con,"SELECT * from area where id_area!=0");

Answer 1

This is not a simple division

mysqli_fetch_assoc($tiempoQueryFinalizados)['finalizados'] / 
mysqli_fetch_assoc($tiempoQueryFinalizados)['c']

Each call to mysqli_fetch_assoc() gets a new row from your resultset. So as the query only returns one row, the second call will return FALSE which equates to zero.

So this would be a better way of doing the retrieval and calculation

$row = mysqli_fetch_assoc($tiempoQueryFinalizados);
$calc = $row['finalizados']] / $row['c'];

Answer 2

Ok I forgot when every call you do to mysqli_fetch* you are jumping to the next register , so only I needed to edit

$tiempoQueryFinalizados = mysqli_query(...

by

$tiempoQueryFinalizados = mysqli_fetch_assoc(mysqli_query(...

now $tiempoQueryFinalizados['finalizados'] / $tiempoQueryFinalizados['c']

works very nice :) thank you all!