PHP - Getting values from while loop

Question

Sorry for asking a simple question.

Im still new to php, so im still learning.

For example using the while($row = mysql_fetch_assoc($sql)), I queried and echoed a single column name "weight", after 4 results, each $row['weight'] has values of 30,15,20,35. How can I fetch these values and perform addition to get the total value of the weight.

<?php

  $sql = mysql_query("SELECT weight FROM table WHERE ID = '$ID'");

  while ($row = mysql_fetch_assoc($sql)){

  echo $row['weight'];

  ?>

Sample output:

I want to perform ADDITION.

30+15+20+35=100

as mysql_query calls are being deprecated with mysqli, I would suggest you take a look at mysqli (as it will be removed at some point, you may end up with non working code in the future). That said, the easiest is to sum it straight in mysql select sum(weight) instead of select weight — Youn Elan, Apr 30 '13 at 02:29

jszobody · Answer 1 · 2013-04-30T02:28:45.613

To to this in PHP just add each weight to a $total variable inside your loop:

$sql = mysql_query("SELECT weight FROM table WHERE ID = '$ID'");
$total = 0;
while ($row = mysql_fetch_assoc($sql)){
    $total += $row['weight'];
}
echo $total;

However you may also want to consider doing it directly in sql:

$sql = mysql_query("SELECT SUM(weight) AS total FROM table WHERE ID = '$ID'");
$row = mysql_fetch_assoc($sql);
$total = $row['total'];

Also note that mysql functions are deprecated as of PHP 5.5 and will be removed removed in the future, you need to look at the mysqli_query or PDO::query instead.

M8R-1jmw5r · Answer 2 · 2013-04-30T02:27:44.140

3

You let mysql calculate that for you:

SELECT SUM(weight) AS total FROM table WHERE ID = '$ID' GROUP BY ID;

Example:

  $sql = sprintf(
      'SELECT SUM(weight) AS total FROM table WHERE ID = '%d' GROUP BY ID', $ID
  );

  $result = mysql_query($sql);

  $total  = $result ? mysql_fetch_assoc($result)['total'] : 0;

But I dislike this example code because it uses the mysql_* functions and PDO is much better.

edited Apr 30 '13 at 02:27

answered Apr 30 '13 at 02:22

M8R-1jmw5r

4,896
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Tnx! I was worried cause I never encountered this one before – raziel2101 Apr 30 '13 at 02:36
About what exactly were you worried? – M8R-1jmw5r Apr 30 '13 at 02:37

score 0 · Answer 3 · answered Apr 30 '13 at 02:21

0

I believe you are looking for something like:

$total = 0;#initialize
while ($row = mysql_fetch_array($sql)){
      $total += $row['weight'];#adds weight to the total
}
echo $total;

answered Apr 30 '13 at 02:21

Class

3,149
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score 0 · Answer 4 · answered Apr 30 '13 at 02:21

0

   $Number_Variable = 0;
  while ($row = mysql_fetch_array($sql)){

  $Number_Variable += $row['weight'];

  }

Then after you have finished your while:

echo $Number_Variable;

answered Apr 30 '13 at 02:21

Daryl Gill

5,464
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score 0 · Answer 5 · answered Apr 30 '13 at 02:22

0

<?php

  $sum = 0;
  $sql = mysql_query("SELECT weight FROM table WHERE ID = '$ID'");

  while ($row = mysql_fetch_array($sql)){

   $sum = $sum + $row['weight']; 


  }

  echo $sum;


  ?>

answered Apr 30 '13 at 02:22

DobotJr

3,929
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score 0 · Answer 6 · answered Apr 30 '13 at 02:22

0

<?php

  $sql = mysql_query("SELECT weight FROM table WHERE ID = '$ID'");

  $total = 0;
  while ($row = mysql_fetch_array($sql)){
    $total = $total + $row['weight'];
  }

    echo $total;

?>

answered Apr 30 '13 at 02:22

parnas

721
5
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score 0 · Answer 7 · edited May 23 '17 at 11:43

Now that you're learning start learning mysql/php with mysqli or pdo cause mysql_* functions are deprecated

$mysqli = new mysqli('server', 'database_user', 'database_pass', 'database_name');
if($mysqli->connect_errno) {
    echo "Error connecting to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}

$my_query = $mysqli->query("SELECT SUM(weight) as total_weight FROM your_table");
if($my_query->num_rows){
    while($row = $my_query->fetch_assoc()){
       echo 'Total weight is: ' . $row['weight'];
    }
}

PHP - Getting values from while loop

7 Answers7