Entity Framework Core Model Building

Model configuration helpers for ModelBuilder, covering the shapes written on almost every model: relationships, indexes, enum storage, and eager loading.

Each helper collapses a fluent-API sequence into one call. The relationship helpers override no convention: requiredness and delete behavior stay inferred from the foreign key's nullability. The others override one deliberately, storing an enum as text, making an index unique, or naming a many-to-many's own join table and key columns. Every one is called inside OnModelCreating and returns the ModelBuilder, so calls chain.

Categories

• Extensions — model configuration helpers on ModelBuilder.

Quick Example

AppDbContext.cs

using Microsoft.EntityFrameworkCore;
using AlmightyShogun.EntityFrameworkCore.ModelBuilding;

public sealed class AppDbContext(
    DbContextOptions<AppDbContext> options
) : DbContext(options)
{
    public DbSet<Account> Accounts => Set<Account>();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.ApplyOneToOne<Account, Profile>(
            account => account.Profile,
            profile => profile.AccountId
        );

        modelBuilder.ApplyOneToMany<Account, Order>(
            account => account.Orders,
            order => order.AccountId
        );

        modelBuilder.ApplyUniqueIndex<Account>(
            account => account.Email
        );

        modelBuilder.ApplyUniqueIndex<Account>(
            account => account.Slug,
            filter: "[Slug] IS NOT NULL"
        );

        modelBuilder.ApplyEnumAsString<Account, Tier>(
            account => account.Tier
        );

        modelBuilder.ApplyManyToMany<Account, Tag>(
            account => account.Tags,
            tag => tag.Accounts,
            "account_tags"
        );
    }
}

Entities.cs

public sealed class Account
{
    public int Id { get; set; }
    public required string Email { get; set; }
    public string? Slug { get; set; }
    public Tier Tier { get; set; }
    public Profile? Profile { get; set; }
    public List<Order> Orders { get; set; } = [];
    public List<Tag> Tags { get; set; } = [];
}

public sealed class Profile
{
    public int Id { get; set; }
    public int AccountId { get; set; }
}

public sealed class Order
{
    public int Id { get; set; }
    public int AccountId { get; set; }
}

public sealed class Tag
{
    public int Id { get; set; }
    public required string Name { get; set; }
    public List<Account> Accounts { get; set; } = [];
}

public enum Tier
{
    Free,
    Pro,
    Enterprise
}