如何在 Entity Framework Core Fluent API 中将基本实体配置重构为单独的类

Question

I am porting over a website I maintain to .Net6 in the next few months. I have upgraded/updated the domain model and am now working on the Fluent API to define my EntityType Configurations.

There used to be a Properties method off modelBuilder where you could define your BaseEntity property configurations ONCE in the OnModelCreating method. Apparently, that didn't make it into EF Core Fluent API.

Base entity class

public abstract class EntityBase : IdBase, IEntity
{
    //private setter = immutable so it will only be created once   
    public DateTime DateCreated { get; private set; } = DateTime.UtcNow;      
    public string CreatedByUserId { get; private set; } = "";

    // use DateTime.UtcNow when modifying
    public DateTime DateModified { get; private set; } = DateTime.UtcNow;   
    public int ModifiedCount { get; private set; } = 0;           
    public string ModifiedByUserId { get; private set; } = "";
    public List<DomainEventBase> DomainEvents = new();
}

For example:

modelBuilder.Properties().Where(x => x.Name == "CreatedByUserId").Configure(x => x.HasMaxLength(Common.Constants.GuidColumnLength));
modelBuilder.Properties().Where(x => x.Name == "ModifiedByUserId").Configure(x => x.HasMaxLength(Common.Constants.GuidColumnLength));
modelBuilder.Properties().Where(x => x.Name == "DateCreated").Configure(x => x.HasColumnType(Common.DateConstants.SqlDataTypeColumn));
modelBuilder.Properties().Where(x => x.Name == "DateModified").Configure(x => x.HasColumnType(Common.DateConstants.SqlDataTypeColumn));

Which I refactor out to a method called ConfigureBaseEntityProperties.

I am not finding a way to accomplish this in EF Core for .Net6. Ideally I would prefer to do it as EntityTypeConfiguration but I can't find a way to get that to work either.

Answer 1

you can still do it like this:

foreach (var property in modelBuilder.Model.GetEntityTypes()
                .SelectMany(type => type.GetProperties())
                .Where(property => property.Name == "CreatedByUserId"))
{
     property.SetMaxLength(Common.Constants.GuidColumnLength);
}