使用部分键的实体框架代码优先自定义映射
是否可以使用 Entity Framework Code First 进行以下映射？
public class Parent
{
[Key]
public int ID {get; set;}
public string statecode{get; set;}
public virtual ICollection<Child> children{get; set;}
}
public class Child
{
[Key, Column(Order = 0)]
public string StateFromCode { get; set; }
[Key, Column(Order = 1)]
public string StateToCode { get; set; }
}
我想在 dbcontext 中指定一个关系，其中子级延迟加载到 Parent 中，并且 Parent.statecode == Child.StateToCode。请注意，StateToCode 是子键的一部分，而不是整个主键。如果可能的话，我应该在下面的数据库上下文中指定什么才能实现这一点？
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
modelBuilder.Entity<Parent>().HasMany(x=>x.children)..............
}
Is it possible to do the following mapping with the Entity Framework Code First?
public class Parent
{
[Key]
public int ID {get; set;}
public string statecode{get; set;}
public virtual ICollection<Child> children{get; set;}
}
public class Child
{
[Key, Column(Order = 0)]
public string StateFromCode { get; set; }
[Key, Column(Order = 1)]
public string StateToCode { get; set; }
}
I would like to specify a relation in my dbcontext where children are lazy loaded into the Parent and Parent.statecode == Child.StateToCode. Note that StateToCode is part of the Child key and not the entire primary key. What should I specify in my DB context below to make this happen if possible at all?
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
modelBuilder.Entity<Parent>().HasMany(x=>x.children)..............
}
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这是不可能的 - 尤其是在代码优先的情况下，关系必须遵循与在数据库中指定引用约束完全相同的规则。因此，唯一有效的关系需要
Child表中的Parent的 Id 列以及该列上的外部约束It is not possible - especially not with code first where relations must follow exactly same rules as specifying referential constraint in the database. So the only valid relation will require
Parent's Id column inChildtable and foreign constraint on this column