外键未更新(使用所需的依赖主体进行配置)
本文关键字:主体 依赖 配置 更新 | 更新日期: 2024-09-23 08:14:10
Fluent API配置:
internal class UserMap : EntityTypeConfiguration<User>
{
public UserMap()
{
Property(x => x.CSL).IsRequired();
//relational properties
HasRequired(x => x.UserType).WithMany(x => x.Users).HasForeignKey(x => x.UserType_ID).WillCascadeOnDelete(true);
HasRequired(x => x.TimelineVolumetry).WithRequiredPrincipal(x => x.User).WillCascadeOnDelete(true);
}
}
internal class TimelineVolumetryMap : EntityTypeConfiguration<TimelineVolumetry>
{
public TimelineVolumetryMap()
{
Property(x => x.AllowedWeeks).IsRequired();
//relational properties
HasRequired(x => x.User).WithRequiredDependent(x => x.TimelineVolumetry).WillCascadeOnDelete(true);
}
}
插入查询:
User u = new User();
u.CSL = csl;
u.UserType_ID = role;
u.TimelineVolumetry = new TimelineVolumetry();
u.TimelineVolumetry.User = u;
ctx.User.Add(u);
ctx.SaveChanges();
在数据库中插入一个用户之后,我得到了TimelineVolumetry
的User_ID = 0
。有没有办法在添加用户时自动设置User_ID
,或者在设置外键后我是否被迫再次保存TimelineVolumetry
?
public class TimelineVolumetry
{
public int ID { get; set; }
public int AllowedWeeks { get; set; }
//relational properties
public int User_ID { get; set; }
public User User { get; set; }
public TimelineVolumetry()
{
AllowedWeeks = 0;
}
}
我看到了一些可以在关系配置中改进的地方。首先,您不需要两次配置User
和TimelineVolumetry
之间的关系,一次就足够了。此外,您不需要使用级联删除来配置关系。如果依赖实体上的外键不可为null(就像您的情况一样),则Code First会在关系上设置级联删除,因此已经设置了它
public class UserMap : EntityTypeConfiguration<User>
{
public UserMap()
{
Property(x => x.CSL).IsRequired();
//relational properties
HasRequired(x => x.UserType).WithMany(x => x.Users).HasForeignKey(x => x.UserType_ID);
HasRequired(x => x.TimelineVolumetry).WithRequiredPrincipal(x => x.User);
}
}
public class TimelineVolumetryMap : EntityTypeConfiguration<TimelineVolumetry>
{
public TimelineVolumetryMap()
{
Property(x => x.AllowedWeeks).IsRequired();
}
}
关于插入,如果你同时创建两个实体,你应该这样做:
User u = new User();
//...
var tv= new TimelineVolumetry();
//set required properties of TimelineVolumetry entity
u.TimelineVolumetry =tv;
//u.TimelineVolumetry.User = u;// you don't need to do this
//...
ctx.User.Add(u);
ctx.SaveChanges();
这将在DB中正确插入两个实体(包括外键列的值)。
更新
恐怕你想要的是不可能的。你不能与未声明为PK的FK创建一对一关系,实体框架要求依赖项的主键也是外键,所以,为了实现你想要的,你可以这样做:
public class TimelineVolumetry
{
public int AllowedWeeks { get; set; }
//relational properties
[Key, ForeignKey("User")]
public int User_ID { get; set; }
public User User { get; set; }
public TimelineVolumetry()
{
AllowedWeeks = 0;
}
}
这是使用数据注释,但使用Fluent Api是这样的:
// Configure User_Id as PK for TimelineVolumetry
modelBuilder.Entity<TimelineVolumetry>()
.HasKey(e => e.User_Id);
// Configure User_Id as FK for TimelineVolumetry
modelBuilder.Entity<User>()
.HasOptional(s => s.TimelineVolumetry) // Mark TimelineVolumetry is optional for User
.WithRequired(ad => ad.User); // Create inverse relationship
如果你想阅读更多关于这个主题的内容,我推荐你这个链接。