'Custom rows lookup
@param key: the key Field
@param values: the values
@param fields: unused (retained for API compatibility)'

def lookup_rows(self, key, values, fields=[]):

    s3db = current.s3db
    ttable = s3db.project_task
    fields = [ttable.id, ttable.name]
    show_project = self.show_project
    if show_project:
        ltable = s3db.project_task_project
        left = ltable.on((ltable.task_id == ttable.id))
        fields.append(ltable.project_id)
    else:
        left = None
    if (len(values) == 1):
        query = (key == values[0])
    else:
        query = key.belongs(values)
    rows = current.db(query).select(left=left, *fields)
    self.queries += 1
    if (show_project and rows):
        project_ids = [row.project_task_project.project_id for row in rows]
        if project_ids:
            self.project_represent.bulk(project_ids)
    return rows
