This is due to one of the breaking changes in EF Core 3.0 and that is: LINQ queries are no longer evaluated on the client So write the query in such way that EF Core can convert the expression into T-SQL or fetch the data into memory and then make your query.
Until custom primitive type persistence is natively supported in Entity Framework, a common work around is to use buddy properties. For each custom primitive within your domain model, you create an associated mapped primitive to hold the value in a format supported by Entity Framework. The custom primitive properties are then calculated from the value … Read more
EF Core 3 To take Ryan’s example: protected override void OnModelCreating(ModelBuilder modelBuilder) { modelBuilder.Entity<SomeTable>(entity => entity.HasCheckConstraint(“CK_SomeTable_SomeColumn”, “[SomeColumn] >= X”); } Docs. EF Core 7+ protected override void OnModelCreating(ModelBuilder modelBuilder) { modelBuilder .Entity<Blog>() .ToTable(b => b.HasCheckConstraint(“CK_Blog_TooFewBits”, “Id > 1023”)); } See this for more details and changes in 7. Docs.
All relationships in your model are required because all foreign key properties (CountryId, RegionId, CityId) are not nullable. For required one-to-many relationships EF will enable cascading delete by convention. Country and Region have multiple delete paths to the Store table, for example if you delete a Country the related Stores can be deleted via three … Read more
Update: If you are using Entity Framework Core you should use the following syntax var hierarchy = from p in ctx.Parents .Include(p => p.Children) .ThenInclude(c => c.GrandChild) select p;
Can you do this with the Entity Framework? Yes; it’s easy. Can you do this with the Entity Framework designer? Unfortunately, that is much harder. The problem you’re having is that the column exists in the storage schema (SSDL) in your EDMX. Removing the column with the GUI designer simply removes it from the client … Read more
Use DropCreateDatabaseAlways initializer for your database. It will always recreate database during first usage of context in app domain: Database.SetInitializer(new DropCreateDatabaseAlways<YourContextName>()); Actually if you want to seed your database, then create your own initializer, which will be inherited from DropCreateDatabaseAlways: public class MyInitializer : DropCreateDatabaseAlways<YourContextName> { protected override void Seed(MagnateContext context) { // seed database … Read more
When I hit this limitation, I changed the type to uniqueidentifier
Default length of string field in code first is 128. If you are using EF validation it will throw exception. You can extend the size by using: [StringLength(Int32.MaxValue)] public string Body { get; set; } This post became somehow popular so I’m adding second approach which also works: [MaxLength] public string Body { get; set; … Read more
After failed attempts to find references to EntityFramework in repositories.config and elsewhere, I stumbled upon a reference in Web.config as I was editing it to help with my diagnosis. The bindingRedirect referenced 5.0.0.0 which was no longer installed and this appeared to be the source of the exception. Honestly, I did not add this reference … Read more