title: ADF data flow how to handle empty string when converting to integer
body: <p>How does one handle the conversion of string to integer when copying data from one sql table to another using ADF data flow?
  I have one field that is empty and using the toInteger() function is causing an error.
  how can I tell the expression to not convert if the value is null?</p>
  
  <p>I see there is an if expression but i am unsure how to get it to work correctly. I tried using the iif, but the copy still fails as the toInteger() function cannot convert an empty string to integer</p>
  
  <p><code>iif(DivisionNumber == ' ',0, toInteger(DivisionNumber))</code></p>