Defining a variable in PHP

[Butterbean]

I know that I have posted a similar question to this but I am still having some confusion that I hoped I could clear up.  Thank you all for being patient with and helping me clean up this mess.

 

Below is the code that is spitting out the bottom error messages.  So, I understand that the way to define a variable which uses += and not send it into a loop, generating a notice is this..

 

Using the top example

 

$meter_multiplier=0;

while ($row5 = sqlsrv_fetch_array($query5)){
meter_multiplier += $row5['meter_multiplier'];
}

 

versus... 

 

$meter_multiplier += $row5['meter_multiplier'];

 

how can I implement this type of statment below.  Should the php be called another name and reference sql that way, so the names are different?

 

example    

 

$meter_multiplier=0;

while ($row5 = sqlsrv_fetch_array($query5)){

meter_multiplier += $row5['meter_mult'];

<?php
$sql5 = "select meter_id, subaccount_number, service_name, service_address, service_address2, service_city, service_st, service_zip, service_contact, basic_charge, energy_charge, base_rate, intermediate_rate, peak_rate, meter_multiplier, raw_material_price FROM [radiogates].[dbo].[ops_invoice] where meter_id ='$comm_id' and subaccount_number='$session_id'";$query5 = sqlsrv_query($conn, $sql5);if ($query5 === false){  exit("<pre>".print_r(sqlsrv_errors(), true));}while ($row5 = sqlsrv_fetch_array($query5)){  	

$meter_multiplier += $row5['meter_multiplier']; 
$raw_material_price += $row5['raw_material_price']; 
$basic_charge += $row5['basic_charge'];
$peak_rate += $row5['peak_rate']; 
$intermediate_rate += $row5['intermediate_rate']; 
$energy_charge += $row5['energy_charge'];
$base_rate += $row5['base_rate']; 
$account_number = $row5['meter_id']; 
$service_name = $row5['service_name']; 
$service_address = $row5['service_address'];
$service_address2 = $row5['service_address2']; 
$service_city = $row5['service_city']; 
$service_st = $row5['service_st']; 
$service_zip = $row5['service_zip'];} 
sqlsrv_free_stmt($query5);
?> 

Notice: Undefined variable: meter_multiplier in C:\xampp1\htdocs\Utrack\invoice.php on line 335

Notice: Undefined variable: raw_material_price in C:\xampp1\htdocs\Utrack\invoice.php on line 335

Notice: Undefined variable: basic_charge in C:\xampp1\htdocs\Utrack\invoice.php on line 335

Notice: Undefined variable: peak_rate in C:\xampp1\htdocs\Utrack\invoice.php on line 335

Notice: Undefined variable: intermediate_rate in C:\xampp1\htdocs\Utrack\invoice.php on line 335

Notice: Undefined variable: energy_charge in C:\xampp1\htdocs\Utrack\invoice.php on line 335

Notice: Undefined variable: base_rate in C:\xampp1\htdocs\Utrack\invoice.php on line 335

[ginerjm]

You can't concatenate to a variable without creating it first. So - before your loop you must initialize the vars