Fields must exist in the map layer. You must list the actual field names rather than the alias names. Returned fields are also the actual field names. However, you are able to use the alias names when you display the results. For optimal performance, limit the output fields to only those you expect to use. Each query must have access to the Shape and Objectid fields for a layer, but your list of fields does not need to include these two fields. To return all fields, specify the wildcard '*' as the value of this parameter. In this case, the query results include all the field values.

Note: The wildcard will not return the geometry (i.e. shape field). In order to return the geometry information the ReturnGeometry must be set to True.