Simple Select not working

[jasonhjohnson]

Hi,

I just posted this issue to the EF Core Github and StackOverflow this morning, but as it turns out, the issue is due to something with EF Plus' query filters: dotnet/efcore#7706 and http://stackoverflow.com/questions/42441235/simple-linq-select-not-working.

When I add the "AsNoFilter()" to my query it works as expected.

Thanks,
Jason

[JonathanMagnan]

Hello @jasonhjohnson ,

Thank you for reporting this issue.

Could you provide me the filter you used? I have tried to replicate it unsuccessfully.

Best Regards,

Jonathan

[jasonhjohnson]

Hi @JonathanMagnan

I'm using several filters so I'm not exactly sure which one is causing the issue, but here are the filters:

this.context.Filter<IBaseEntityWithTenant>(QueryFilterType.Tenant, q => q.Where(x => x.TenantId == tenantId));
this.context.Filter<IBaseEntityWithTenantAndContact>(QueryFilterType.TenantWithContact, q => q.Where(x => x.TenantId == tenantId));
this.context.Filter<IPlant>(QueryFilterType.TenantForPlant, q => q.Where(x => x.Plant.TenantId == tenantId));
this.context.Filter<ITemplate>(QueryFilterType.TenantForTemplate, q => q.Where(x => x.Template.Plant.TenantId == tenantId));
this.context.Filter<IOrder>(QueryFilterType.TenantForOrder, q => q.Where(x => x.SalesOrder.Plant.TenantId == tenantId));
this.context.Filter<IItem>(QueryFilterType.TenantForItem, q => q.Where(x => x.Item.Plant.TenantId == tenantId));
                  
// Soft delete
this.context.Filter<IBaseEntity>(QueryFilterType.SoftDelete, q => q.Where(x => !x.IsDeleted));

Thanks,
Jason

[JonathanMagnan]

Hello @jasonhjohnson ,

Thank you, I have enough information to understand the issue now.

Unfortunately, this issue (even if it appears) is not caused by our library but because Entity Framework Core doesn't handle yet correctly the cast method.

Here is an example how to reproduce it without our library:

using (var ctx = new CurrentContext())
{
	int keyId = 1;

	var ids = ctx.MyTables
		.Cast<IMyTable>()
		.Cast<MyTable>()
		.Where(x => x.SomeKey.Equals(keyId))
		.Select(x => x.MyFieldIntegerIWant)
		.ToList();
}

public class IMyTable
{
            
}

public class MyTable : IMyTable
{
    public int MyTableId { get; set; }
    public int SomeKey { get; set; }
    public int MyFieldIntegerIWant { get; set; }
}

The same LINQ work perfectly under EF6.

In short, it seems to be caused by our library since you filter using an interface. So to apply the filter, our library need to cast first into "IMyTable" and apply the filter then cast it back to "MyTable" which is similar to this scenario.