我有以下型号:
class Contract
{
string ContractID{get;set;}
ICollection<Part> Parts{get;set;}
}
class Part
{
string PartID{get;set;}
ICollection<Contract> Contracts{get;set;}
}
问题是Part和Contract之间的关系还包含以下附加信息:
class ContractParts
{
Contract{get;set;}
Part{get;set;}
Date{get;set;} //additional info
Price{get;set;} //additional info
}
我如何为此编写实体上下文?
答案 0 :(得分:41)
在这种情况下,您必须以这种方式为实体建模:
public class Contract
{
public virtual string ContractId { get; set; }
public virtual ICollection<ContractPart> ContractParts { get; set; }
}
public class Part
{
public virtual string PartId { get;set; }
public virtual ICollection<ContractPart> ContractParts { get; set; }
}
public class ContractPart
{
public virtual string ContractId { get; set; }
public virtual string PartId { get; set; }
public virtual Contract Contract { get; set; }
public virtual Part Part { get; set; }
public virtual string Date { get; set; } //additional info
public virtual decimal Price { get; set; } //additional info
}
在派生上下文中,您必须定义:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<ContractPart>()
.HasKey(cp => new { cp.ContractId, cp.PartId });
modelBuilder.Entity<Contract>()
.HasMany(c => c.ContractParts)
.WithRequired()
.HasForeignKey(cp => cp.ContractId);
modelBuilder.Entity<Part>()
.HasMany(p => p.ContractParts)
.WithRequired()
.HasForeignKey(cp => cp.PartId);
}
答案 1 :(得分:5)
或许更好的方法是这个答案? Create code first, many to many, with additional fields in association table
它不需要流畅的API,也可以在连接表上设置PK。