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>() ...

In Entity Framework 7 which property Attribute creates an index in code first?

In Entity Framework 7 (7.0.0-rc1-final) which property Attribute creates an index?...I would normally add an index to a sql table to improve look up times so I assume I need to specify this in my class?...public class Account { [Key] [Required] publ...

Does EF Core SaveChanges validate against the data annotations

I have a model with Data Annotations and I was wondering if it was possible to have the SaveChanges method fail if the Data Annotation failed?...I was expecting SaveChanges to throw an exception along the lines of "Test2 is outside the Range of 2 to 4". ...

Validating entities using data annotations or fluent api in EF 7.0 (In Memory)

I can't verify and test my database by in memory providers. for example I set these properties to required : ...public abstract class Log { #region Properties public Guid Id { get; set; } [Required] public string ClientIp { get; set; } ...

Entity Framework Core Data Annotation Database Generated Values

The Entity Framework Core documentation for ...Generated Properties... makes it seem like Data Annotations can be used for generated code first ..."timestamp"... properties such as created/updated on as a ...DateTime... type....When trying to use the foll...

EntityFramework Core auto generate key id property

Using .Net Core MVC. I need to setup my model so that EntityFrameworkCore will auto generate the ID property. I thought that just adding the ...[Key]... annotation would do this, but it doesn't. As a matter of fact, it produces an error when the ID fie...

EF Core one to many to many to one relationship

I've worked with databases for a long time now but am new to Entity Framework. I handle both the aspects of programming and database development. As a db developer, I try to keep it clean so this structure that I came up with works well for me but I'm not...

asp.net core model four decimal places validation

In my model in asp.net core when I scaffold my database it only allows for a number with two decimal places like 0.10 but, I am not allowed to insert four decimal places into my database....Below is my model.... public class Order { public int Ord...

Can't set primary key and foreign key on one column

So I try to create some ASP.NET project with EF Core....I want to set propert of one entity as primary key and foreign key to another entity. The relationship is ...0..1 - 1.... I use ...DataAnnotations...:...public class OfficeAssignment { [Key, Fore...

Entity Framework Core, DELETE CASCADE, and [Required]

I am running into an issue DELETE CASCADE in Entity Framework Core that I can't seem to find a good solution to....Here's a super simplified version of my model:...User {UserID, Name} Recipe {RecipeID, UserID} Ingredient {IngredientID, UserID} RecipeIngre...

How do I generate a primary key that is not random?

I want to be able to set the value of my primary key to an auto increment number. At the moment it generates a random key such as 13917c50-6b8c-4405-82ce......I want to be able to tell the system "Hey, I want request number to start at 1 (or 1000 or whate...

Writing Range Data Annotation with Fluent API in Entity Framework Core

Description...As I'm trying to adopt ...Clean Architecture..., I want to move away from ...Data Annotations... and use ...Fluent API... which, personally, I started to prefer a lot more....However, I'm not too skilled in this way of implementing things...

ASP.NET Core 3 remote validation with EF Core 3

Bit of an EF beginner's question really, but I'm running into a problem using the [Remote] validation using ASP.NET MVC Core 3 with EF Core 3....Following one of Microsoft's posts, it suggested keeping everything "DRY" (don't repeat yourself). So as dire...