使用c/实体框架将查询从一个实体重定向到另一个实体

DuplicateOf

ALTER TABLE [Company] 
    ADD COLUMN [DuplicateOf] bigint NULL, 
    FOREIGN KEY [DuplicateOf] REFERENCES [Company] ([Id]);

public class Company
{
    // ...

    public Company DuplicateOf { get; set; }

    // May be useful, hides check for duplicate logic:
    public bool IsDuplicate => DuplicateOf != null;

    // May be useful as well, 
    // returns the non-duplicate uniue company, not a duplicate, either linked or current:
    public Company EffectiveCompany => DuplicateOf ?? this;
}

EffectiveCompany

GetCompany(bigint id)