title: Adding a calculated field in LINQ select results?
body: <p>I have a LINQ query (using with EF)</p>
  
  <p>Basically I want to add a column in Select results based on value of another column.</p>
  
  <p>I have <code>PaymentDate</code> column in DB table but not <code>Paid</code> column. If there is null in <code>PaymentDate</code> column it also shows payment is false and if it has some date in it means paid is true. </p>
  
  <p>Here is my query, please guide me how to do that.</p>
  
  <pre><code> var selectedResults=
      from InvoiceSet in Invoices
      join BookedAreasSet in BookedAreas 
      on InvoiceSet.InvoiceID equals BookedAreasSet.InvoiceID
      join AreaSet in Areas on BookedAreasSet.AreaID equals AreaSet.AreaID
      select new     {InvoiceSet.InvoiceNumber,InvoiceSet.Amount,InvoiceSet.TotalDiscount,InvoiceSet.GST,       InvoiceSet.PaymentDate,InvoiceSet.ShoppingCentreID,BookedAreasSet.BookedAreaID,
  AreaSet.Name,Here I want to add calculated value column based on InvoiceSet.PaymentDate value}
  </code></pre>