title: error- Each column has to have a unique name when you’re returning the query
body: <p>I am trying to run reporting services with below SQL query</p>
  
  <pre><code>select ca.callingpartynumber, ca.originalcalledpartynumber, case
  when calledpartylastname is not null then ca.calledpartylastname + ',' + calledpartyfirstname 
  else p1.name end,
  p1.location, p1.dept, p1.title,
  case
  when callingpartylastname is not null then ca.callingpartylastname + ',' + callingpartyfirstname 
  else p3.name end
  from calldata.calldetailreport ca
  join ps_bc_peoplesource_base p1 on ca.originalcalledpartynumber = replace(p1.bc_int_phone, '-', '')
  left outer join ps_bc_peoplesource_base p3 on ca.callingpartynumber = replace(p1.bc_int_phone, '-', '')
  where originalcalledpartynumber in (select replace(bc_int_phone, '-', '') internal_modified  from ps_bc_peoplesource_base where bc_lan_id = 'f7c')
  --and datetimedisconnect between @startdate  and @enddate --1221
  </code></pre>
  
  <p>I get this error-</p>
  
  <blockquote>
    <p>“An item with the same key has already been added.”</p>
  </blockquote>