HttpGet 与三个关系表与 dot net 核心 web api

Question

我有树状表 Sectors 、 Centers 和 Managements 部门和中心之间的关系是一对多的，中心和管理之间的关系也是一对多的我想检索 Json 以获取部门有中心列表和中心有管理列表但我得到了这个结果

[{"secID":4,"cod":"400000000","name":"قطاع الأمن والخدمات المالية والإدارية","Centers":[{"ID":18,"Cent":1.0,"name":"الإدارة العامة لمكتب رئيس القطاع\"5","Mangments":[],"cod":"0401000000","SecID":4},{"ID":19,"Cent":2.0,"name":"(أ) الإدارة المركزية للخدمات الأمنية","Mangments":[],"cod":"0402000000","SecID":4},{"ID":20,"Cent":3.0,"name":"(ب)  الإدارة المركزية للخدمات الإدارية","Mangments":[],"cod":"0403000000","SecID":4},{"ID":21,"Cent":4.0,"name":"(ج) الإدارة المركزية للخدمات المالية","Mangments":[],"cod":"0404000000","SecID":4}]}

管理：[] 这是我的代码

public class Sectors
{

    [Key]

    public Int32 secID { get; set; }
    
    public string cod { get; set; }
    public string name { get; set; }

    public virtual ICollection<Centers> Centers { get; set; }
    = new List<Centers>();

}
public class Centers
{
    [Key]

    public Int32 ID { get; set; }
    public double? Cent { get; set; }
    public string name { get; set; }
    public virtual ICollection<Mangments> Mangments { get; set; }
    = new List<Mangments>();
    public string cod { get; set; }
    [ForeignKey("SecID")]
    //public Sectors sectors { get; set; }
    public Int32 SecID { get; set; }

}

public class Mangments
{

    [Key]

    public Int32 ID { get; set; }
    public string cod { get; set; }

    public string name { get; set; }
    public double? mang { get; set; }

    [ForeignKey("CenterID")]
    //public Sectors sectors { get; set; }
    public Int32 CenterID { get; set; }
}

这是获取方法的代码

 [HttpGet]
    public async Task<ActionResult<IEnumerable<Sectors>>> GetSectors()
    {
        return _context.Sectors.OrderBy(c => c.name).Include(c => c.Centers).ToList();
    }

我可以更新什么以获得我想要的结果

Answer 1

您可以使用 Select() 方法：

_context.Sectors.OrderBy(c => c.name)
                .Include(s => s.Centers.Select(c => c.Mangments))
                .ToList();

或

您可以使用 ThenInclude() 方法 https://entityframeworkcore.com/querying-data-include-theninclude

_context.Sectors.OrderBy(c => c.name)
                .Include(c => c.Centers)
                   .ThenInclude(c => c.Mangments)
                .ToList();

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