title: Group sum distinct values from another field
body: <p>I have two tables that are joined via a left join on the customer number as follows:</p>
  
  <pre><code>          Customers                                Transactions
  AccountNumber   CustomerBalance         AccountNumber  TransAmount  TransDate
  1                $100.00                 1               $100.00     8/1/2017
  2                $200.00                 2               $200.00     8/2/2017
  3                $300.00                 4               $50.00      8/2/2017
  4                $400.00                 4               $100.00     8/4/2017
  5                $500.00                 4               $50.00      8/5/2017
  6                $600.00                 6               $100.00     8/4/2017
  </code></pre>
  
  <p>These Tables are combined and end up looking like the below table:</p>
  
  <pre><code>          Combined Table
  AccountNumber   CustomerBalance     TransAmount  TransDate
  1                $100.00             $100.00     8/1/2017
  2                $200.00             $200.00     8/2/2017
  3                $300.00             
  4                $400.00             $50.00      8/2/2017                
  4                $400.00             $100.00     8/4/2017                
  4                $400.00             $50.00      8/5/2017
  5                $500.00            
  6                $600.00             $100.00     8/4/2017
  </code></pre>
  
  <p>What I need is to sum the balance column but only for each account number once,
  so Account number 4 appears 3 times because of 3 transactions but I only want it to sum the balance once. I also need this to happen on a group level of crystal reports so if I were to group my data based on accounts 1-10 and then 11-20 and so on it would only give me each separate group's balance. </p>
  
  <p>Is this possible in crystal reports because I am stuck on the Idea of using running sums to only show the account balance once but crystal doesn't let you summarize a running sum field and I know the workaround for that is to do a running total sum for the header while printing records however I don't know how to transfer that over to a group level/header on crystal report.</p>
  
  <p>Expected Result for the sample data sum should be $2100.00</p>