EF Core Database First HasNoKey

Question

I have a database table created 20 years ago in my company, it is only used for journaling, with NO PRIMARY KEY or INDEX. I can't alter that table.

I understood that we need to call HasNoKey() in code first approach.

But how can I apply HasNoKey in this case? Since it is a Database First approach.

You can check this article learn.microsoft.com/en-us/ef/core/modeling/keyless-entity-types — Ramil Aliyev 007
– Ramil Aliyev 007, Commented Feb 6, 2020 at 13:55

Pang · Accepted Answer · 2021-02-16 03:38:41Z

16

In your DbContext class' OnModelCreating method, you do something like this:

modelBuilder .Entity<MyEntity>(builder => { builder.HasNoKey(); builder.ToTable("MY_ENTITY"); });

Read more about it here:
https://learn.microsoft.com/en-us/ef/core/modeling/keyless-entity-types?tabs=fluent-api

edited Feb 16, 2021 at 3:38

Pang

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answered Feb 6, 2020 at 13:58

Ricardo Peres

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4 Comments

s k Over a year ago

No code first approach. The Database was created 20 years ago.

War Over a year ago

@sk This should still apply to DB first ... DB first IS code first, it's just that we generate the Entity Types from the DB first, but it should still create a DbContext with a ConfigureModel method in to which we tell the model that this is going on in the DB.

Slagmoth Over a year ago

I can't resolve .HasNoKey() on my newly created entity.

Ricardo Peres Over a year ago

See learn.microsoft.com/en-us/ef/core/modeling/…

Sadiq Khan · Accepted Answer · 2023-01-31 19:04:47Z

7

Use [Keyless] Attribute of model class.

answered Jan 31, 2023 at 19:04

Sadiq Khan

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2 Comments

Denny Jacob Over a year ago

Simpler solution!!!

nesticle8bit Over a year ago

Which using do you used?

Aaron Carta · Accepted Answer · 2024-08-12 00:29:36Z

The Keyless attribute was the best solution (don't have reputation yet to comment).

You will want to add the Microsoft.EntityFrameworkCore.Abstractions nuget package to the project with your entities.

And: using Microsoft.EntityFrameworkCore;

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