EF Core添加1:1关联引发级联删除循环错误的问题咨询

问题1：多对多关系删除行为的理解 #

• 查阅资料后我的理解：多对多关系中删除一方对象时，会级联删除关联表的对应映射条目，但不会删除关联表另一方的对象，该理解是否正确？

问题2：添加1:1关联后执行Update-Database报错 #

场景 #

为County模型添加与Address模型的1:1关联后，执行Update-Database命令时触发错误。

新增关联的代码 #

public class Address
{
    public int Id { get; private set; }
    public string? Address1 { get; set; }
    // additional properties
}

public class User
{
    public int Id { get; private set; }
    public Address Address { get; private set; }
    // additional properties
}

public class County
{
    public int Id { get; private set;  }
    // 新增该Address属性后触发错误
    public Address Address { get; private set; }
    // additional properties
}

报错日志 #

fail: Microsoft.EntityFrameworkCore.Database.Command[20102]
Failed executing DbCommand (9ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE TABLE [CountyUser] (
[CountiesId] int NOT NULL,
[FollowersId] int NOT NULL,
CONSTRAINT [PK_CountyUser] PRIMARY KEY ([CountiesId], [FollowersId]),
CONSTRAINT [FK_CountyUser_Counties_CountiesId] FOREIGN KEY ([CountiesId]) REFERENCES [Counties] ([Id]) ON DELETE CASCADE,
CONSTRAINT [FK_CountyUser_Users_FollowersId] FOREIGN KEY ([FollowersId]) REFERENCES [Users] ([Id]) ON DELETE CASCADE
);
Failed executing DbCommand (9ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
CREATE TABLE [CountyUser] (
[CountiesId] int NOT NULL,
[FollowersId] int NOT NULL,
CONSTRAINT [PK_CountyUser] PRIMARY KEY ([CountiesId], [FollowersId]),
CONSTRAINT [FK_CountyUser_Counties_CountiesId] FOREIGN KEY ([CountiesId]) REFERENCES [Counties] ([Id]) ON DELETE CASCADE,
CONSTRAINT [FK_CountyUser_Users_FollowersId] FOREIGN KEY ([FollowersId]) REFERENCES [Users] ([Id]) ON DELETE CASCADE
);

Introducing FOREIGN KEY constraint 'FK_CountyUser_Users_FollowersId' on table 'CountyUser' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
Could not create constraint or index. See previous errors.

疑问与需求 #

1. 我认为错误原因是County和User的级联删除会同时触发Address的删除，导致循环或多条级联路径，该理解是否正确？
2. Address记录不会被共享，如何配置EF允许删除关联的Address对象？若不可行，如何通过Fluent API设置不删除Address记录，或其他可行方案？我已在MyDbContext.SaveChanges()/SaveChangesAsync()中处理过一对多的删除逻辑，可在此添加额外代码。

内容的提问来源于stack exchange，提问作者David Thielen