code: func (q *Query) Select(fields ...string) *Query {
  	for _, f := range fields {
  		if strings.TrimSpace(f) != "" {
  			q.addColumns = append(q.addColumns, f)
  		}
  	}
  	return q
  }
docs: // Select allows to query only fields passed as parameter.
  // c.Select("field1", "field2").All(&model)
  // => SELECT field1, field2 FROM models