title: How to create calculated column with data from another list
body: <p>I have the following situation: List A has two columns (Name, Amount) and in List B (Name) I want to add a calculated column which should be the sum of all entries in List A that have the same name as in List B. Example:</p>
  
  <p>List A:</p>
  
  <pre><code>NAME      Amount
  L0011     100
  L0011     50
  L0020     234
  </code></pre>
  
  <p>So in List B I want the calculated column to show:</p>
  
  <pre><code>NAME      Amount
  L0011     150
  L0020     234
  </code></pre>
  
  <p>How can this be done? Workflow (as soon as I add/mod an entry in List A, update List B) or something else? Thanks </p>