Entity Framework Core - Knowledge Base (KB)
39 results in tag: entity-framework-core-2.1
How to UPDATE modified and deleted entities on SaveContext?
Goal is to track who had changed and deleted an entity....So I have an entity that implements an interface:...interface IAuditable { string ModifiedBy {get;set;} } class User: IAuditable { public int UserId {get;set;} public string UserName {get...
asked by Roman Pokrovskij
The seed entity for entity type 'X' cannot be added because the was no value provided for the required property "..ID"
I'm playing wit ...EF Core 2.1 Preview 2.... I have troubles with HasData (Seed) method in ...OnModelCreating(ModelBuilder modelBuilder)...My model is simple POCO class that has no annotation....public class Tenant { public int TenantID {get; set;} ...
asked by Tomino
EF Core Group By translation support on conditional sum
I was really excited to hear that EF Core 2.1 will be supporting group by translations. I downloaded the preview and started testing it out but found that I am still not getting group by translations in a number of places....In the code snippet below, the...
asked by jaromey
Entity Framework Core: Fail to update Entity with nested value objects
I have an entity that has a value object and this value object has another value object. My issue is that when updating the entity along with the value objects, the entity with the parent value object get updated but the child value object didn't. note, i...
asked by yo2011
How to create relationships between entities with existing database that does not contain foreign keys
Using Entity Framework Core 2.0...Stuck with company's production database which has primary keys defined for each table but no foreign keys defined for any relationships....Dependent records in the database have id fields which are intended to relate to ...
asked by JakRuzL
'No database provider has been configured for this DbContext' using SQLite
I'm just experimenting with EF Core and SQLite and have been slightly stumped by the issue....If I attempt to configure the database like this:...services.AddDbContext<MyDbContext>(options => options.UseSqlite("Filename=./App_Data/dashboard.db") ); ...And...
asked by Jammer
How to get all saved Entity values in DbContext either via Events or override SaveChangesAsync()
Need a centralized solution to get the resulting ...Entity... as persisted to the Db, potentially inside the ...SaveChangesAsync()... and ...SaveChanges()... methods of my ...DbContext... or via an event listener....Need resulting entity value to contain ...
asked by ttugates
Scaffolding Keyless Models on entity framework core 2.1
I have a simple console app and i am trying to scaffold all my models but i have some of them that does not have defined a primary key, Entity framework 2.1 give support to that kind of tables but still get this warning ...Unable to identify the primary k...
asked by Dennis Gonzalez
EF Core 2.1 project Add-Migration NullReferenceException
I am getting a ...NullReferenceException... on a project recently converted to dotnet core 2.1....My EF library project is dotnet core 2.1. Code first migrations....CsvHelper 6.0.2 Microsoft.EntityFrameworkCore 2.1.0 Microsoft.EntityFrameworkCore.Design 2...
asked by Padhraic
EF Core Migration error: Database 'MyDatabaseName' already exists. Choose a different database name
I am running ASP.NET Core 2.1 with EF Core 2.1 application on Windows Server 2016 with SQL Server 2017 Web edition....At the end of ...public void Configure(IApplicationBuilder app, ...... method in ...Startup.cs... I call ...context.Database.Migrate();..
asked by Makla
EF CORE: is it possible to support two models in one database?
Is it possible to support two different EF Core models with all "migrations functionality" in one database? ...I guess I should somehow separate ...dbo......._EFMigrationsHistory... ? Can't find such option in documentation.
asked by Roman Pokrovskij
Get related data without relationship between tables
When I have two models with one to many relationship, they look like the models below:...public class Student { [Key] [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)] public int StudentID { get; set; } public string Name { g...
asked by pitaridis
Entity Framework Core - More than one Discriminator for derived classes
I have a model that is structurd as follows (fields ommited for brevity):...public enum ActivityType { Production, Downtime } public enum ActivityStatus { Planned Actual } public abstract class Activity { public virtual ActivityType ActivityType {ge...
asked by Chris
Combine BinaryExpression and Expression<Func<dynamic, bool>> in C#
How can I combine ...BinaryExpression... and ...Expression<Func<dynamic / T, bool>>...?...For example:...void AddGlobalFilter<T>(Expression<Func<T, bool>> expr) { var parameter = Expression.Parameter(type, "t"); var member = Expression.Property(fi...
asked by Makla
What could cause `UserManager` to return the wrong user?
Something rather scary is happening on my ASP.NET Core 2.1.0 MVC site. While I was browsing, all of a sudden it shows I am logged in as a different user (who also happens to be browsing the site at that time)....I can't pinpoint whether there is a specifi...
asked by Steven Jeuris
Execute async non selectable stored procedure in EF Core 2.1
I'm trying to execute async non selectable stored procedure in EF Core 2.1.... return Ok( await db.Set() .FromSql($"EXECUTE PROCEDURE MY_PROC({id})") .ToListAsync()); ...Error...:...The type arguments for method ...
asked by mrapi
Entity Framework Core 2.1 - Generic Model in FromSql method
I have been using the below approach to call stored procedure in EF core 2.1...In DBContext...public DbQuery<SomeModel> SomeModels { get; set; } ...Class...var result = context.SomeModels.FromSql("SQL_SCRIPT").ToList(); ...I'm trying to create a generic m...
asked by VPP
EF Core tracking entities with same id multiple times
I simply want to update an industry property of a client object. To do so, I retrieve the client from the DB using a repository. This would result in my industry (example id:149) being tracked. ... var client = await _clientRepository.GetAsync(...
asked by Seb
Many to many self reference table - guid Id changes itself
I have a many to many table that references. Itself it sounds crazy so here's an image for a better view of the problem ...https://i.stack.imgur.com/lj2zZ.png...I use guids as primary and foreign keys. When I try to add a new instance of ...Foo... to the...
asked by john
How to do aggregate functions such as count in Entity Framework Core
I have this SQL that I would like to execute in Entity Framework Core 2.1:...Select ItemTypeId, Count(ItemTypeId) as Count from Items i where i.ParentId = 2 group by ItemTypeId ...How do I do that?...This is what I came up with, but it returns zero:...v...
asked by Greg Gum