来自不同类的 Lambda 表达式中的多个 Where 子句

Question

我创建了一个名为AppRequest的主类，在它之下，还有其他类Suspense、SuspenseDetails。 当我查询数据时，我想从 AppRequest 查询一个，从 Suspense 查询一个，从 SuspenseDetails 查询一个。

代码是这样写的

int y = int.Parse(((System.Security.Claims.ClaimsIdentity)User.Identity).FindFirst("UserId").Value);
List<AppRequest> SuspencesforSettle = db.AppRequest.Where(s => s.Create_By == y).Where(s=> s.Status==true).ToList();

我想从 AppRequest 中查询 - CreatedBy 和 Status 并且还需要从 SuspenseDetails 中检查 Settle_Status。 但是，从 where 条件我只能获取 AppRequest 类下的字段。你们能帮我解决这个问题吗？

这就是我的模型设计的方式。

 public class AppRequest
    {
        [Key]
        public int Id { get; set; }

        [Required]
        [Display(Name = "Request Type")]
        public int ReqType { get; set; }

        [Required]
        [Display(Name = "Requesting By")]
        public int Req_By { get; set; }

        [Required]
        [Display(Name = "Requesting Date")]
        public DateTime Req_Date { get; set; } = DateTime.Now;

        [Required]
        [Display(Name = "Request Location")]
        public int Req_Location { get; set; }

        [Required]
        [Display(Name = "Request Heading")]
        public string Req_Heading { get; set; }

        [Display(Name = "Cover Note")]
        public string Req_CoverNote { get; set; }

        [Required]
        [Display(Name = "Company Name")]
        public int Company_Id { get; set; }
        public bool Status { get; set; }
        public int Create_By { get; set; }
        public DateTime Created_Date { get; set; }
        public int Modified_By { get; set; }
        public DateTime Modified_Date { get; set; } = DateTime.Now;
        public int Approval_Status { get; set; }

        public virtual IList<Suspense> Suspense { get; set; }
     }

 public class Suspense
    {
        [Key]
        public int Id { get; set; }

        [Required]
        [ForeignKey("AppRequest")]
        public int Req_Id { get; set; }
        public virtual AppRequest AppRequest { get; set; }

        public virtual IList<SuspenseDetails> SuspenseDetails { get; set; }
    }

 public class SuspenseDetails
    {
        [Key]
        public int Id { get; set; }

        [Required]
        [ForeignKey("Suspense")]
        public int Sus_Id { get; set; }
        public virtual Suspense Suspense { get; set; }

        [Required]
        [Display(Name = "Requesting Amount")]
        public decimal Req_Amount { get; set; }

        [Required]
        [Display(Name = "Amount In Words")]
        public string Req_Amount_In_Words { get; set; }

        [Required]
        [Display(Name = "Purpose")]
        public string Purpose { get; set; }

        [Required]
        [Display(Name = "Cash Requesting for ")]
        public int Req_For { get; set; }

        public string Approved_Suspense_Id { get; set; }
        public bool Cash_Issued { get; set; }
        public int Cash_IssuedBy { get; set; }
        public DateTime? Cash_Issued_Date { get; set; }
        public bool Settled { get; set; }

    }

Answer 1

你可以这样写：

var result =
    db
        .AppRequest
        .Where(appRequest => appRequest.Create_By == creator)
        .Where(
            appRequest =>
            appRequest
                .Suspense
                .SelectMany(suspense => suspense.SuspenseDetails)
                .Any(suspenseDetails => suspenseDetails.Settled)
        )
        .ToList();