No value generator is available for properties of type 'Decimal'

[scottengle]

I am working with an existing legacy database table that contains a primary key defined as "numeric(18, 0)". In Entity Framework 7.0.0-beta3, this is mapping to a CLR type of Decimal. The Microsoft.Data.Entity.SqlServer.SqlServerValueGeneratorSelector (and its base class Microsoft.Data.Entity.Identity.ValueGeneratorSelector) do not have a comparison for decimal types defined.

Per the error message (see below), I have two options: 1) set a value for the property before adding the entity or 2) configure a value generator for properties of type 'Decimal'. The database is not configured to allow for inserts that include the primary key, so I believe I'm left with the second option.

How do I configure a value generator for properties of type 'Decimal'?

When I try to modify items in an existing DBSet, I get this error message:

System.NotSupportedException was unhandled by user code
  HResult=-2146233067
  Message=The 'Id' on entity type 'Bar' does not have a value set and no value generator is available for properties of type 'Decimal'. Either set a value for the property before adding the entity or configure a value generator for properties of type 'Decimal'.
  Source=EntityFramework.Core
  StackTrace:
       at Microsoft.Data.Entity.Identity.ValueGeneratorSelector.Select(IProperty property)
       at Microsoft.Data.Entity.SqlServer.SqlServerValueGeneratorSelector.Select(IProperty property)
       at Microsoft.Data.Entity.Identity.ValueGeneratorCache.GetGenerator(IProperty property)
       at Microsoft.Data.Entity.ChangeTracking.ValueGenerationManager.MayGetTemporaryValue(IProperty property)
       at Microsoft.Data.Entity.ChangeTracking.StateEntry.MayGetStoreValue(IProperty property)
       at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
       at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
       at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
       at Microsoft.Data.Entity.ChangeTracking.StateEntry.MayGetStoreValue()
       at Microsoft.Data.Entity.ChangeTracking.StateEntry.PrepareToSave()
       at Microsoft.Data.Entity.ChangeTracking.StateManager.<>c.<SaveChanges>b__28_1(StateEntry e)
       at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
       at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
       at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
       at Microsoft.Data.Entity.ChangeTracking.StateManager.SaveChanges()
       at Microsoft.Data.Entity.DbContext.SaveChanges()
       ...
  InnerException: 

My model:

namespace Foo.Models
{
    public class Bar
    {
        public decimal Id { get; set; }
        public string Name { get; set; }
        public string Password { get; set; }
        public DateTimeOffset LastModified { get; set; }
    }
}

My model context:

namespace Foo.Models
{
    public class BarContext : DbContext
    {
        public DbSet<Bar> Bars { get; set; }

        public BarContext(DbContextOptions<BarContext> options)
            : base(options)
        { }

        protected override void OnConfiguring(DbContextOptions options)
        {
        }

        protected override void OnModelCreating(ModelBuilder builder)
        {
            builder.Entity<Bar>(e =>
               {
                   e.Metadata.SqlServer().Table = "BARS";
                   e.Property(c => c.Id).Metadata.SqlServer().Column = "BAR_ID";
                   e.Property(c => c.Id).Metadata.SqlServer().ColumnType = "numeric";
                   e.Property(c => c.Name).Metadata.SqlServer().Column = "BAR_NAME";
                   e.Property(c => c.LastModified).Metadata.SqlServer().Column = "LAST_MODIFIED_DTM";
               });

            builder.Entity<Bar>()
                .Key(e => e.Id);

            builder.Entity<Bar>()
                .Property(e => e.Name)
                .MaxLength(50)
                .Required();

            builder.Entity<Bar>()
                .Property(e => e.Password)
                .MaxLength(25)
                .Required();
        }

        public override int SaveChanges()
        {
            ChangeTracker.DetectChanges();

            foreach(var item in ChangeTracker.Entries<Bar>()
                .Where(e => e.State == EntityState.Modified || e.State == EntityState.Added))
            {
                var prop = Model.GetEntityType(typeof(Bar)).GetProperty("LastModified");
                item.StateEntry[prop] = (DateTimeOffset) DateTime.Now;
            }

            return base.SaveChanges();
        }
    }
}

My data service:

namespace Foo.Models
{
    public class BarSvc : IBarSvc
    {
        private BarContext db;

        public BarSvc(BarContext context)
        {
            db = context;
        }

        public Bar AddBar(Bar bar)
        {
            db.Bars.Add(bar);

            if(db.SaveChanges() > 0)
            {
                return bar;
            }
            return null;
        }

        public bool DeleteBar(int id)
        {
            var bar = db.Bars.FirstOrDefault(x => x.Id == id);
            if(bar != null)
            {
                db.Bars.Remove(bar);
                return db.SaveChanges() > 0;
            }
            return false;
        }

        public Bar GetBar(int id)
        {
            return db.Bars.FirstOrDefault(x => x.Id == id);
        }

        public IEnumerable<Bar> GeBars()
        {
            return db.Bars.OrderBy(x => x.Name).AsEnumerable();
        }

        public Bar UpdateBar(int id, Bar bar)
        {
            var existingBar = db.Bars.FirstOrDefault(x => x.Id == id);
            if(existingBar == null)
            {
                return null;
            } 

            existingBar.Name = bar.Name;
            existingBar.Password = bar.Password;

            db.Bars.Update(existingBar);

            if(db.SaveChanges() > 0)
            {
                return existingBar;
            }
            else
            {
                return null;
            }
        }
    }
}

[scottengle]

Update: this issue is still present in 7.0.0-beta4

   at Microsoft.Data.Entity.ValueGeneration.ValueGeneratorSelector.Create(IProperty property)
   at Microsoft.Data.Entity.SqlServer.SqlServerValueGeneratorSelector.Create(IProperty property)
   at Microsoft.Data.Entity.Utilities.ThreadSafeDictionaryCache`2.GetOrAdd(TKey key, Func`2 factory)
   at Microsoft.Data.Entity.ValueGeneration.ValueGeneratorCache.GetOrAdd(IProperty property, Func`2 factory)
   at Microsoft.Data.Entity.SqlServer.SqlServerValueGeneratorSelector.Select(IProperty property)
   at Microsoft.Data.Entity.ChangeTracking.Internal.ValueGenerationManager.MayGetTemporaryValue(IProperty property)
   at Microsoft.Data.Entity.ChangeTracking.Internal.InternalEntityEntry.MayGetStoreValue(IProperty property)
   at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Microsoft.Data.Entity.ChangeTracking.Internal.InternalEntityEntry.MayGetStoreValue()
   at Microsoft.Data.Entity.ChangeTracking.Internal.InternalEntityEntry.PrepareToSave()
   at Microsoft.Data.Entity.ChangeTracking.Internal.StateManager.<>c.<SaveChanges>b__27_1(InternalEntityEntry e)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Microsoft.Data.Entity.ChangeTracking.Internal.StateManager.SaveChanges()
   at Microsoft.Data.Entity.DbContext.SaveChanges()
   at PartnerData.Models.PartnerContext.SaveChanges() in C:\projects\PartnerData\src\PartnerData\Models\PartnerContext.cs:line 56
   at PartnerData.Data.PartnerDataSvc.UpdatePartner(Int32 id, Partner partner) in C:\projects\PartnerData\src\PartnerData\Data\PartnerDataSvc.cs:line 62
   at PartnerData.API.Controllers.PartnerDataController.UpdatePartner(Int32 id, Partner partner) in C:\projects\PartnerData\src\PartnerData\API\PartnerDataController.cs:line 88

[ajcvickers]

This should be fixed now.