efcore 关联三张表查询

定义模型:

namespace House.Models.PublicClass
{
    /// <summary>
    /// 城市
    /// </summary>
    public class Province
    {
        /// <summary>
        /// 城市编号
        /// </summary>
        /// 
        [Key]
        public int ProvinceSerialId { get; set; }
        /// <summary>
        /// 城市名称
        /// </summary>
        public string ProvinceTitle { get; set; }
        /// <summary>
        /// 设置导航属性
        /// </summary>
        public List<City> City { get; set; }
    }
    /// <summary>
    /// 区域
    /// </summary>
    public class City
    {
        /// <summary>
        /// 区域编号
        /// </summary>
        /// 
        [Key]
        public int CitySerialId { get; set; }
        /// <summary>
        /// 区域名称
        /// </summary>
        public string CityTile { get; set; }
        /// <summary>
        /// 设置导航属性
        /// </summary>
        public List<Area> Area { get; set; }
    }
    /// <summary>
    /// 站点
    /// </summary>
    public class Area
    {
        /// <summary>
        /// 站点编号
        /// </summary>
        [Key]
        public int AreaSerialId { get; set; }
        /// <summary>
        /// 站点名称
        /// </summary>
        public string AreaTitle { get; set; }
    }

}

当查询的时候:

var data = await _ctx.Provinces.Include(r => r.City)
    .ThenInclude(r => r.Area)
    .ToListAsync();