title: The conversion of the varchar value overflowed an int column
body: <p>For some value of <code>@nReservationID</code>:</p>
  
  <pre><code>SELECT @phoneNumber=
    CASE 
      WHEN  ISNULL(rdg2.nPhoneNumber  ,0) = 0 THEN ISNULL(rdg2.nMobileNumber, 0)
      ELSE ISNULL(rdg2.nPhoneNumber  ,0)
    END 
  from tblReservation_Details_Guest  rdg2 
  where nReservationID=@nReservationID
  </code></pre>
  
  <p>Why do I get this error?</p>
  
  <blockquote>
    <p>Msg 248, Level 16, State 1, Procedure
    USP_CRE_WEB_MEMBER_AUTOGENERATEDECV, Line 136 The conversion of the
    varchar value '08041159620' overflowed an int column.</p>
  </blockquote>