Reverse Engineering: Enable pluralization/singularization when scaffolding a model from a database

Database scaffolding has no pluralization service and the entity models are generated mapping the exact name of database objects. My suggestion is to enable this pluralization through a DI service that could be overridden at the ef CLI like this:

dnx ef dbcontext scaffold "Server=myserver;Database=Foo;user id=me;password=pwd" EntityFramework.SqlServer --use-pluralization "MyAssembly.PlurarizationService, MyAssembly"

And on Razor templates this could be exposed as:

...
@:namespace @Model.Namespace
@:{
@:    public class  @PluralizationService.Singularize(Model.EntityType.Name)
@:    {
...

I think the default service could be the one shipped with EF6 (System.Data.Entity.Design.PluralizationServices.PluralizationService)

[gdoron]

Thanks @rowanmiller, in case someone else finds it helpful, I wrapped it in an extension method:

public static void UseDbSetNamesAsTableNames(this DbContext dbContext, ModelBuilder modelBuilder)
{

    var dbSets = dbContext.GetType().GetRuntimeProperties()
        .Where(p => p.PropertyType.Name == "DbSet`1")
        .Select(p => new
                            {
                                PropertyName = p.Name,
                                EntityType = p.PropertyType.GenericTypeArguments.Single()
                            })
        .ToArray();

    foreach (var type in modelBuilder.Model.GetEntityTypes())
    {
        var dbset = dbSets.SingleOrDefault(s => s.EntityType == type.ClrType);
        if (dbset != null)
        {
            type.Relational().TableName = dbset.PropertyName;
        }

    }
}

And used it like this:

protected override void OnModelCreating(ModelBuilder builder)
{
    base.OnModelCreating(builder);
    this.UseDbSetNamesAsTableNames(builder);

But I get an error says cannot find the object “Posts”

I checked what EF is trying to execute with dnx ef migrations script 20160211201857_second -o c:\temp\rename.txt and pasted it here. EF is using the new name Posts before it was renamed, so that’s a bug.

Since it’s a just a test application I created for a lecture I will present in the office next week I don’t mind using dnx ef database 0 and start all over again. But out of curiosity what should I do if it is a real production application? fiddle with the __EFMigrationsHistory table?

Thank you very much Rowan, I really like what you did with EF 7 and in ASP.NET 5 in general!

[rowanmiller]

@gdoron stick this code at the start of OnModelCreating and it will give you what you are after 😄

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    var dbSets = GetType().GetProperties()
        .Where(p => p.PropertyType.Name == "DbSet`1")
        .Select(p => new
        {
            PropertyName = p.Name,
            EntityType = p.PropertyType.GenericTypeArguments.Single()
        })
        .ToArray();

    foreach (var type in modelBuilder.Model.GetEntityTypes())
    {
        var dbset = dbSets.SingleOrDefault(s => s.EntityType == type.ClrType);
        if(dbset != null)
        {
            type.Relational().TableName = dbset.PropertyName;
        }

    }

    // Other configuration code...
}