Displaying the sum just in one row - php

Question

I hav this sql query:
$sql = "SELECT (SELECT SUM(total_pay) FROM workers) total,workers. * FROM workers WHERE projects_id = ".$id;
And I want to display data into table rows:
$stmt = mysqli_query($con, $sql) or die($sql."<br/><br/>".mysqli_errno($con));
<?php while($rows = mysqli_fetch_array($stmt)){ ?>
<form action="update_del.php" method="post">
<th>Payments</th>
<th>Date</th>
<th>Project</th>
<th width="25%">Delete</th>
<tr>
<?php while($rows = mysqli_fetch_array($stmt)){ ?>
<tr>
<td align="center"><?php echo $rows['total_pay']?></td>
<td align="center"><?php echo $rows['date_of_pay']?></td>
<td align="center"><?php echo $name['project_name'] ?></td>
<td align="center"><!--<input class="imgClass_insert" type="submit" name="submit1" value="" />-->
<input class="imgClass_dell" type="submit" onClick="return confirm('Are you sure you want to delete?')" name="delete_workers" value=""/>
</td>
</tr>
</tr>
<tr>
<td colspan="3">Total <?php echo $name['project_name']?></td>
<td><?php echo $rows['total'] ?></td>
</tr>
<?php } ?>
</table>
The problem is, that the sum of the payment is repeated with every row displayed, so how can I display the sum query just once in the end of the table ? Should put it in a single query specified for the sum only ?

Answer 1

You can either remove the total from your query and use PHP to calculate, or you can just simply store the total and use it outside your while statement. Something like
<?php
$total = 0;
while($rows = mysqli_fetch_array($stmt)){
$total = $rows['total'];
?>
<tr>
<td align="center"><?php echo $rows['total_pay']; ?></td>
<td align="center"><?php echo $rows['date_of_pay']; ?></td>
<td align="center"><?php echo $name['project_name']; ?></td>
<td align="center">
<!--<input class="imgClass_insert" type="submit" name="submit1" value="" />-->
<input class="imgClass_dell" type="submit" onClick="return confirm('Are you sure you want to delete?')" name="delete_workers" value=""/>
</td>
</tr>
<?php } ?>
<tr>
<td colspan="3">Total <?php echo $name['project_name']; ?></td>
<td><?php echo $total; ?></td>
</tr>
</table>
Though since you're traversing all the results anyway it would be best to remove it from the SQL and calculate it.
$sql = "SELECT workers.* FROM workers WHERE projects_id = ".$id;
<?php
$total = 0;
while($rows = mysqli_fetch_array($stmt)){
$total += $rows['total_pay'];
?>
<tr>
<td align="center"><?php echo $rows['total_pay']; ?></td>
<td align="center"><?php echo $rows['date_of_pay']; ?></td>
<td align="center"><?php echo $name['project_name']; ?></td>
<td align="center">
<!--<input class="imgClass_insert" type="submit" name="submit1" value="" />-->
<input class="imgClass_dell" type="submit" onClick="return confirm('Are you sure you want to delete?')" name="delete_workers" value=""/>
</td>
</tr>
<?php } ?>
<tr>
<td colspan="3">Total <?php echo $name['project_name']; ?></td>
<td><?php echo $total; ?></td>
</tr>

Answer 2

If i understand your problem properly, then this might help you to generate sum in the last rows as you require.
"SELECT total_pay, date_of_pay,project_name
FROM workers WHERE project_id=".$id."
UNION
SELECT 'ALL', SUM(total_pay)
FROM workers";