实体框架返回一个实体的每个引用表

Question

我尝试将我的 Java EE 项目重写为 C# Rest API 项目。 对于数据库映射，我使用实体框架，并且在从表中获取记录时遇到一些问题。 首先，我有一个被其他表引用的表：

CREATE TABLE Bibliogr (
  Bknumber INT PRIMARY KEY NOT NULL,
  Authors VARCHAR(500),
  Source VARCHAR(500),
  Title VARCHAR(1000)
);

映射的类如下：

public partial class Bibliogr
    {
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
        public Bibliogr()
        {
            this.AcOpTabl = new HashSet<AcOpTabl>();
            this.ConstSel = new HashSet<ConstSel>();
            this.CuryTabl = new HashSet<CuryTabl>();
            this.DecrTabl = new HashSet<DecrTabl>();
            this.DensTabl = new HashSet<DensTabl>();
            this.DielDiss = new HashSet<DielDiss>();
            this.Dielectr = new HashSet<Dielectr>();
            this.ElemTabl = new HashSet<ElemTabl>();
            this.ElOpTabl = new HashSet<ElOpTabl>();
            this.EquationTabl = new HashSet<EquationTabl>();
            this.EsOpTabl = new HashSet<EsOpTabl>();
            this.HardTabl = new HashSet<HardTabl>();
            this.HeatExpn = new HashSet<HeatExpn>();
            this.HeatTabl = new HashSet<HeatTabl>();
            this.MechTabl = new HashSet<MechTabl>();
            this.MnOpTabl = new HashSet<MnOpTabl>();
            this.ModfTabl = new HashSet<ModfTabl>();
            this.NlOpTabl = new HashSet<NlOpTabl>();
            this.PlavTabl = new HashSet<PlavTabl>();
            this.PzElTabl = new HashSet<PzElTabl>();
            this.RefrcInd = new HashSet<RefrcInd>();
            this.SuspTabl = new HashSet<SuspTabl>();
            this.Wavepure = new HashSet<Wavepure>();
        }
    
        public int Bknumber { get; set; }
        public string Authors { get; set; }
        public string Source { get; set; }
        public string Title { get; set; }
    
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<AcOpTabl> AcOpTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<ConstSel> ConstSel { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<CuryTabl> CuryTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<DecrTabl> DecrTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<DensTabl> DensTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<DielDiss> DielDiss { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<Dielectr> Dielectr { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<ElemTabl> ElemTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<ElOpTabl> ElOpTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<EquationTabl> EquationTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<EsOpTabl> EsOpTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<HardTabl> HardTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<HeatExpn> HeatExpn { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<HeatTabl> HeatTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<MechTabl> MechTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<MnOpTabl> MnOpTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<ModfTabl> ModfTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<NlOpTabl> NlOpTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<PlavTabl> PlavTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<PzElTabl> PzElTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<RefrcInd> RefrcInd { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<SuspTabl> SuspTabl { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<Wavepure> Wavepure { get; set; }
    }

有很多我不想从我的请求中获得的HashSet。我怎样才能改变这种行为？我只需要这个表的值，而不需要其他表。

请求结果：

{  
   "AcOpTabl":[  ],
   "ConstSel":[  ],
   "CuryTabl":[  ],
   "DecrTabl":[  ],
   "DensTabl":[  ],
   "DielDiss":[  ],
   "Dielectr":[  ],
   "ElemTabl":[  ],
   "ElOpTabl":[  ],
   "EquationTabl":[  ],
   "EsOpTabl":[  ],
   "HardTabl":[  ],
   "HeatExpn":[  ],
   "HeatTabl":[  ],
   "MechTabl":[  ],
   "MnOpTabl":[  ],
   "ModfTabl":[  ],
   "NlOpTabl":[  ],
   "PlavTabl":[  ],
   "PzElTabl":[  ],
   "RefrcInd":[  ],
   "SuspTabl":[  ],
   "Wavepure":[  ],
   "Bknumber":4,
   "Authors":"Niizeki N.,Yamada N.,Toyoda H.",
   "Source":"Jap.J.Appl.Phys.,1967,v.6,N.3,p.318-327",
   "Title":"Growth ridges, etched hillocks and crystal structure of lithium niobate"
}

Answer 1

我假设您在 EntityFramework 的 DbContext 中启用了延迟加载。当序列化发生时，每个属性都会被访问，并且 EF 会为您加载它。

这种情况的好解决方案是删除

virtual

属性上的

ICollection

关键字。这是选择性禁用延迟加载。

您还可以通过这样做来完全禁用延迟加载

public class YourContext : DbContext 
{ 
    public YourContext() 
    { 
        // Default behaviour is true
        this.Configuration.LazyLoadingEnabled = false; 
    } 
}