Where are Entity Framework Core conventions?

Question

using EF 6.1+ there were times where we need to add or remove existing conentions. The code looks more or less like:

public class MyContext : DbContext     {             protected override void OnModelCreating(DbModelBuilder modelBuilder)             {                 modelBuilder.Conventions.AddFromAssembly(Assembly.GetExecutingAssembly());                 modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();                 modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();                 modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();                  base.OnModelCreating(modelBuilder);             } } 

how do the same in EF core? Modelbuilder has no Conventions property :(

Answer 1

I'm porting some code from EF to EF Core 2.1+ and can't wait for EF Core 3.0 so wrote a few extension methods which help a bit..

public static IEnumerable<IMutableEntityType> EntityTypes(this ModelBuilder builder) {     return builder.Model.GetEntityTypes(); }  public static IEnumerable<IMutableProperty> Properties(this ModelBuilder builder) {     return builder.EntityTypes().SelectMany(entityType => entityType.GetProperties()); }  public static IEnumerable<IMutableProperty> Properties<T>(this ModelBuilder builder) {     return builder.EntityTypes().SelectMany(entityType => entityType.GetProperties().Where(x => x.ClrType == typeof(T))); }  public static void Configure(this IEnumerable<IMutableEntityType> entityTypes, Action<IMutableEntityType> convention) {     foreach (var entityType in entityTypes)     {         convention(entityType);     } }  public static void Configure(this IEnumerable<IMutableProperty> propertyTypes, Action<IMutableProperty> convention) {     foreach (var propertyType in propertyTypes)     {         convention(propertyType);     } } 

with these you can write conventions similar to those in EF 6.1.x, for example.

// equivalent of modelBuilder.Conventions.Remove<PluralizingTableNameConvention>(); modelBuilder.EntityTypes()             .Configure(et => et.Relational().TableName = et.DisplayName());  // Put the table name on the primary key modelBuilder.Properties()             .Where(x => x.Name == "Id")             .Configure(p => p.Relational().ColumnName = p.DeclaringEntityType.Name + "Id");  // Mark timestamp columns as concurrency tokens modelBuilder.Properties()             .Where(x => x.Name == "Timestamp")             .Configure(p => p.IsConcurrencyToken = true); 

For EF Core 3.0 the metamodel methods have changed slightly so you need

modelBuilder.EntityTypes()             .Configure(et => et.SetTableName(et.DisplayName()));  modelBuilder.Properties()             .Where(x => x.Name == "Id")             .Configure(p => p.SetColumnName(BaseName(p.DeclaringEntityType.Name) + "Id")); 

Haven't checked this for efficiency but unless your model is huge it shouldn't pose a problem

This can be extended with other helpers for foreign keys, indexes etc

Answer 2

Looks like it's still not in EF Core 2.0. So here's one way of achieving it. I had done this to apply consistent behaviour to certain attributes, but to address the examples in your question you could try this:

protected override void OnModelCreating(ModelBuilder modelBuilder) {     // equivalent of modelBuilder.Conventions.AddFromAssembly(Assembly.GetExecutingAssembly());     // look at this answer: https://stackoverflow.com/a/43075152/3419825      // for the other conventions, we do a metadata model loop     foreach (var entityType in modelBuilder.Model.GetEntityTypes())     {         // equivalent of modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();         entityType.Relational().TableName = entityType.DisplayName();          // equivalent of modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();         // and modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();         entityType.GetForeignKeys()             .Where(fk => !fk.IsOwnership && fk.DeleteBehavior == DeleteBehavior.Cascade)             .ToList()             .ForEach(fk => fk.DeleteBehavior = DeleteBehavior.Restrict);     }      base.OnModelCreating(modelBuilder); } 

You should be able to do a lot of things with entityType