title: Crystal formula for displaying varbinary image data in the report
body: <p>I have a table used in a stored procedure, in the database which has two columns. One is 'signature' (<code>varbinary</code> datatype) which is an image and the other is 'name' (<code>varchar</code> datatype).</p>
  
  <p>I want to display the signature on the Crystal report, but if it's not present in the database, I want to display the name instead. Can someone help me with a formula because the formula that I have mentioned below does not work.</p>
  
  <pre><code>IF {rpt_SP_for_signature;1.signature} &lt;&gt; "" THEN
     {rpt_SP_for_signature;1.signature} 
  ELSE {rpt_SP_for_signature;1.name} 
  </code></pre>
  
  <p>This throws this error:</p>
  
  <blockquote>
    <p>A blob field cannot be used in a formula</p>
  </blockquote>