为何Entity Framework会将传入值替换为新的增量值？

Hey there, let's break this down to help you figure out how to troubleshoot and search for solutions effectively!

第一步：先把问题具体化 #

You said you're stuck but don't know how to search—first, narrow down what exactly is going wrong. Ask yourself:

• Is it a database mapping issue? Like EF Core throwing errors when setting up relationships between Make/Model/Features?
• Is it a view rendering problem? Can't display related data (like a Model's Features or its parent Make) in your MVC views?
• Is it a business logic bug? Issues when adding/editing vehicle records, like validation failures or incorrect data handling?
• Is it a controller/API issue? Can't fetch or save associated entities properly in your controller actions?

第二步： Use your domain model to refine search keywords #

First, let's fill out the incomplete Model class (since it looks cut off) to match your system's intent:

public class Model {
    public int Id { get; set; }
    public string Name { get; set; }
    public int MakeId { get; set; } // Foreign key linking to Make
    public Make Make { get; set; }
    public ICollection<Feature> Features { get; set; } // Relationship to Features
    public Model() {
        Features = new Collection<Feature>();
    }
}

// Assuming your Feature class looks like this
public class Feature {
    public int Id { get; set; }
    public string Name { get; set; }
    public ICollection<Model> Models { get; set; } // Many-to-many with Model
    public Feature() {
        Models = new Collection<Model>();
    }
}

With this model, here are targeted search keyword examples for common issues:

• For EF Core many-to-many setup problems: ASP.NET Core MVC EF Core configure many-to-many between Model and Feature
• For displaying related data in views: ASP.NET Core MVC view show ICollection<Feature> from Model entity
• For fetching associated entities in controllers: ASP.NET Core MVC EF Core Include related Make and Features when querying Model

第三步： General troubleshooting tips #

• Check error details first: Look for exact error messages in Visual Studio's Output window, browser dev tools console, or your project's log files. Copy those error phrases into your search—they're the most direct way to find solutions.
• Test with a minimal case: Strip down your code to the basics. First get Make and Model working together (save, fetch, display), then add Features once that's stable.
• Verify EF Core configurations: If you're using data annotations, double-check that [ForeignKey] or [InverseProperty] attributes are placed correctly. If using fluent API, confirm your relationship setup in DbContext.

内容的提问来源于stack exchange，提问作者Sam