title: Conversion failed when converting the nvarchar value to datatype int
body: <p>I have this two stored procedure that return data:</p>
  
  <pre><code>ALTER proc [dbo].[spBuscarUrl]
  @CodigoContrato nvarchar(255),  
  @url nvarchar(255) OUTPUT  
  AS    
  
      SET NOCOUNT ON;  
      SELECT @url = url  
      FROM v_compras_y_contrataciones AS cc  
      WHERE CodigoContrato = @CodigoContrato;  
  RETURN  
  </code></pre>
  
  <p>When I'm trying to return the value for the second stored procedure, the error says:</p>
  
  <pre><code>ALTER procedure [dbo].[spCaller]
  AS BEGIN
  DECLARE @URL nvarchar(255);  
  EXECUTE spBuscarUrl  
      'MIREX-2017-00001', @url = @URL OUTPUT;  
  RETURN convert(nvarchar(255),@URL);  
  END
  </code></pre>
  
  <p><strong>Msg 245, Level 16, State 1, Procedure spCaller, Line 6
  Conversion failed when converting the nvarchar value '<a href="https://comunidad.comprasdominicana.gob.do//Public/Tendering/OpportunityDetail/Index?noticeUID=DO1.NTC.2" rel="nofollow noreferrer">https://comunidad.comprasdominicana.gob.do//Public/Tendering/OpportunityDetail/Index?noticeUID=DO1.NTC.2</a>' to data type int.</strong></p>