Entity Framework Core - Knowledge Base (KB)

How to specify Unique Key in EF 7 Code First with Data Annotations

You can specified a Unique Key with Fluent Api:...public class MyContext : DbContext { public DbSet<User> Users { get; set; } protected override void OnModelCreating(ModelBuilder modelBuilder) { modelBuilder.Entity<User>() ...

Entity Framework Core Code-First: Cascade delete on a many-to-many relationship

I'm working on an ASP.NET MVC 6 project with Entity-Framework Core (version ..."EntityFramework.Core": "7.0.0-rc1-final"...) backed by a SQL Server 2012 express DB....I need to model a many-to-many relationship between a ...Person... entity and an ...Addr...

How to Cleanup & generate fresh migration for existing DB?

We wish to get rid of 100s of migration classes as DB schema in production is final....Here are the steps I followed:...Delete Migrations folder....Add-Migration -??...What command line switches, could help us?...EDIT:...If all goes well Up() method of mi...

Getting DbUpdateException when adding a row

I'm trying to add a record in a table, but it's not working. The error message tells me that I cannot insert an explicit value in identity column for ...ProductCategories..., but I don't know that I'm doing that. Maybe there is something I'm not getting a...

entity framework 6 - seeding database throws System.NullReferenceException

I'm using .net core 2 and entityframework 6.2. I'm trying to seed database with some needed base data....I didn't find the Database.SetInitializer method. So I googled and found another way to seed my database in ...Main... method of ...Program... class (...

Entity Framework Core 2.1 problem with DetachedLazyLoadingWarning

I get an exception with DetachedLazyLoadingWarning:...Error generated for warning 'Microsoft.EntityFrameworkCore.Infrastructure.DetachedLazyLoadingWarning: An attempt was made to lazy-load navigation property 'Product' on detached entity of type 'Delivery...

"the term 'add-migration' is not recognized as the name of a cmdlet" visual studio 2019

enter image description here...I'm trying to use entity frame work core and have a fresh asp.net core project open. When i attempt to install Microsoft.EntityFrameworkCore.SqlServer through nuget package manager i get the following error. ...Package Micro...