如何在实体框架中创建多对多映射？

Question

在这种情况下，我有2个实体，例如Contract，Media。public class Media : Entity{    public string Name {get; set;}    public bool Enabled    *//other properties can be ignored..*}public class Contract : Entity{    public string Code {get; set;}    *//other properties can be ignored..*}合同有许多媒体，看来它们是多对多的。但！！首先在EF代码，我需要在ContractMedia表（EF自动生成）中再添加3个字段。例如StartDate，EndDate和Price。无法将其添加到媒体实体中。在这种情况下如何映射？

Answer 1

无需使用Fluent API，即可添加到@Tomas答案。

public class Media // One entity table

{

    public int Id { get; set; }

    public string Name { get; set; }

    public virtual ICollection<ContractMedia> ContractMedias { get; set; }

}

public class Contract // Second entity table

{

    public int Id { get; set; }

    public string Code { get; set }

    public virtual ICollection<ContractMedia> ContractMedias { get; set; }

}

public class ContractMedia // Association table implemented as entity

{

    [Key]

    [Column(Order = 0)]

    [ForeignKey("Media")]

    public int MediaId { get; set; }

    [Key]

    [Column(Order = 1)]

    [ForeignKey("Contract")]

    public int ContractId { get; set; }

    public DateTime StartDate { get; set; }

    public DateTime EndDate { get; set; }

    public double Price { get; set; }

    public virtual Media Media { get; set; }

    public virtual Contract Contract { get; set; }

}