EF 4.1 Fluent API dB首关系映射问题

本文关键字：关系 映射 问题 dB API Fluent EF | 更新日期: 2023-09-27 17:49:25

我有以下表格，

  1. 产品(pro_iIDX (PK), pro_sName)
  2. 制造商(man_iIDX (PK), man_sName)
  3. ProductManufacturer(pma_iIDX[PK]， pma_iProductRef[FK]， pma_iManufacturerRef[FK]， pma_bAvailable)

我有以下poco，

public class ProductInfo  
{  
    public int IDX { get; set; }  
    public string Name { get; set; }
    public virtual ICollection<ProductManufacturerInfo> C0ProductManufacturers 
        { get; set; }  
}  
public class ManufacturerInfo  
{  
    public int IDX { get; set; }  
    public string Name { get; set; }  
    public virtual ICollection<ProductManufacturerInfo> C0ProductManufacturers 
        { get; set; }  
}  
public class ProductManufacturerInfo  
{  
    public int IDX { get; set; }  
    public bool Available { get; set; }  
    public virtual ManufacturerInfo C0Manufacturer { get; set; }  
    public virtual ProductInfo C0ProductInfo { get; set; }  
}

我使用了下面的映射但没有成功，

public ProductManufacturerConfiguration()  
{  
    ToTable("ProductManufacturer");  
    HasKey(p => p.IDX);  
    Property(p => p.IDX).HasColumnName("pma_iIDX");  
    Property(p => p.Available).HasColumnName("pma_bAvailable");  
    Property(p => p.ProductRef).HasColumnName("pma_iProductRef");  
    Property(p => p.ManufacturerRef).HasColumnName("pma_iManufacturerRef");  
    //I have tried  
    HasRequired(p => p.ManufacturerInfo)
            .WithMany(c => c.C0ProductManufacturers)
            .Map(m => m.MapKey("pma_iManufacturerRef"));  
    HasRequired(p => p.ProductInfo)
            .WithMany(c => c.C0ProductManufacturers)
            .Map(m => m.MapKey("pma_iProductRef"));  
    //As well as  
    HasRequired(p => p.C0Manufacturer)
            .WithMany(c => c.C0ProductManufacturers)
            .HasForeignKey(p => p.ManufacturerRef);  
    HasRequired(p => p.C0Product)
            .WithMany(c => c.C0ProductManufacturers)
            .HasForeignKey(p => p.C0Product);
}

从我的试验，dB首先抱怨没有找到ManufacturerInfo_IDX时，我执行以下，

var query = from p in _context.Product  
    select p;

如果我先执行代码，将创建以下表:

ProductManufacturer(
            pma_iIDX[PK], 
            pma_iProductRef, 
            pma_iManufacturerRef, 
            pma_bAvailable, 
            ManufacturerInfo_IDX, 
            ProductInfo_IDX)

EF 4.1 Fluent API dB首关系映射问题

我几乎不相信您提供的示例是您的实际代码，因为它甚至无法编译。复制真实的代码来显示问题有这么难吗?

如此:

public class ProductInfo
{
    public int IDX { get; set; }
    public string Name { get; set; }
    public virtual ICollection<ProductManufacturerInfo> C0ProductManufacturers
    { get; set; }
}
public class ManufacturerInfo
{
    public int IDX { get; set; }
    public string Name { get; set; }
    public virtual ICollection<ProductManufacturerInfo> C0ProductManufacturers
    { get; set; }
}
public class ProductManufacturerInfo
{
    public int IDX { get; set; }
    public bool Available { get; set; }
    public int ManufacturerRef { get; set; }        
    public virtual ManufacturerInfo C0Manufacturer { get; set; }
    public int ProductRef { get; set; }
    public virtual ProductInfo C0ProductInfo { get; set; }
}
public class ProductManufacturerConfiguration : EntityTypeConfiguration<ProductManufacturerInfo>
{
    public ProductManufacturerConfiguration()  
    {  
        ToTable("ProductManufacturer");  
        HasKey(p => p.IDX);  
        Property(p => p.IDX).HasColumnName("pma_iIDX");  
        Property(p => p.Available).HasColumnName("pma_bAvailable");
        Property(p => p.ProductRef).HasColumnName("pma_iProductRef");
        Property(p => p.ManufacturerRef).HasColumnName("pma_iManufacturerRef");  
        //I have tried  
        HasRequired(p => p.C0Manufacturer)
                .WithMany(c => c.C0ProductManufacturers)
                .Map(m => m.MapKey("pma_iManufacturerRef"));
        HasRequired(p => p.C0ProductInfo)
                .WithMany(c => c.C0ProductManufacturers)
                .Map(m => m.MapKey("pma_iProductRef"));  
        //As well as  
        HasRequired(p => p.C0Manufacturer)
                .WithMany(c => c.C0ProductManufacturers)
                .HasForeignKey(p => p.ManufacturerRef);  
        HasRequired(p => p.C0ProductInfo)
                .WithMany(c => c.C0ProductManufacturers)
                .HasForeignKey(p => p.ProductRef);
    }
}

主要问题是ProductManufacturerInfo的键不应该是IDX。IDX更像是多对多关联中的"有效负载"。解决这个问题的一种方法是指定一个真键，这样映射就很容易了:

public class ProductManufacturerInfo
{
    public int IDX { get; set; }
    public bool Available { get; set; }
    public int C0ManufacturerIDX { get; set; }
    public virtual ManufacturerInfo C0Manufacturer { get; set; }
    public int C0ProductInfoIDX { get; set; }
    public virtual ProductInfo C0ProductInfo { get; set; }
}

那么你的映射:

public class ProductManufacturerConfiguration 
    : EntityTypeConfiguration<ProductManufacturerInfo>
{
    public ProductManufacturerConfiguration()
    {
        ToTable("ProductManufacturer");
        HasKey(p => new { p.C0ManufacturerIDX, p.C0ProductInfoIDX });
        Property(p => p.IDX)
           .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
    }
}
相关文章：