/// <summary>
        /// 创建映射
        /// </summary>
        /// <param name="mapping">映射实体</param>
        /// <returns>如果映射已经存在,则返回已经存在的映射(用户ID和映射类型);如果不存在则创建后返回</returns>
        public Mapping CreateMapping(Mapping mapping)
        {
            var mp = GetMappingByLocalUserId(mapping.LocalUserId, mapping.MappingType);

            if (mp != null)
            {
                return(mp);
            }
            mappingRepository.Create(mapping);
            return(mapping);
        }