脚手架控制器 mvc5 时出错

Question

Hi when i try adding a controller using the controller actions and entity framework, it gives me an error saying:

"there was an error with the selected code generator: unable to retrieve metadata for 'Music.Model.Customer'. one or more validation errors were detected during model generation:

Music.Data.Customer : EntityType 'Customer' has no key defined. Define the key for this entity type.

Images: EntityType:EntitySet 'images' is based on type 'Customer that has no keys defined.

I did build my context before adding the controller

Answer 1

In your model, you should decorate a property with the [Key] attribute. For example:

public partial class Customer
{
    [Key]
    public int CustomerId { get; set; }
    ...
    ...

}

Entity Framework will recognise the primary key of a table if the column is named Id. If your table does not have a primary key field named Id, you can identify the primary key field by setting the [Key] attribute.