Muonroi.EntityFrameworkCore.Configuration 1.0.0-alpha.16

Muonroi.EntityFrameworkCore.Configuration

Composable EF Core entity configuration with a template method pattern for schema-divergent multi-tenancy.

In multi-tenant deployments each site shares 70–80% of the same schema but diverges on a handful of column names, lengths, and constraints. This package provides two mechanisms to express that divergence cleanly: a base class (MEntityConfigurationBase<TEntity>) that separates core schema from site-specific overrides via ordered template methods, and a [SiteColumn] attribute (applied by SiteColumnExtensions.ApplySiteColumnOverrides) for lightweight declarative per-site remapping. It depends only on Muonroi.Core.Abstractions and Microsoft.EntityFrameworkCore.Relational.

Installation

dotnet add package Muonroi.EntityFrameworkCore.Configuration --prerelease

Quick Start

Option A — virtual method overrides (MEntityConfigurationBase<TEntity>)

Derive one configuration class per entity in your core library and override site-specific hooks in each site project:

// Core library — shared schema for all sites
public class OrderConfiguration : MEntityConfigurationBase<Order>
{
    protected override void ConfigureTable(EntityTypeBuilder<Order> builder)
        => builder.ToTable("ORDERS").HasKey(e => e.Id);

    protected override void ConfigureCoreColumns(EntityTypeBuilder<Order> builder)
    {
        builder.Property(e => e.OrderNo).HasColumnName("ORDER_NO").HasMaxLength(50);
        builder.Property(e => e.Status).HasColumnName("STATUS").IsRequired();
    }
}

// Site "BRAVO" — override only what differs
public class BravoOrderConfiguration : OrderConfiguration
{
    protected override void ConfigureSiteColumns(EntityTypeBuilder<Order> builder)
        => builder.Property(e => e.OrderNo).HasColumnName("BOOKING_NUMBER").HasMaxLength(25);
}

Register via EF Core's assembly scan inside DbContext.OnModelCreating:

modelBuilder.ApplyConfigurationsFromAssembly(typeof(BravoOrderConfiguration).Assembly);

Option B — [SiteColumn] attribute + ApplySiteColumnOverrides

Annotate a site-specific entity class and call the extension once during model building:

public class BravoOrder
{
    public long Id { get; set; }

    [SiteColumn(Name = "BOOKING_NUMBER", MaxLength = 25)]
    public string? BookingNo { get; set; }

    [SiteColumn(IsRequired = true, DefaultValue = "N")]
    public string? Status { get; set; }

    // No attribute → convention: CONTAINER_NO
    public string? ContainerNo { get; set; }
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    base.OnModelCreating(modelBuilder);
    modelBuilder.ApplySiteColumnOverrides<BravoOrder>("BRAVO");
}

Properties without [SiteColumn] are automatically mapped to UPPER_SNAKE_CASE by convention (e.g. ContainerNo → CONTAINER_NO).

Features

• Template method base class — MEntityConfigurationBase<TEntity> calls five ordered hooks: ConfigureTable → ConfigureCoreColumns → ConfigureCoreIndexes → ConfigureSiteColumns → ConfigureSiteIndexes. Core methods are abstract; site methods are virtual no-ops, making them optional to override.
• EF-native discovery — implements IEntityTypeConfiguration<TEntity>, so ApplyConfigurationsFromAssembly picks up all configurations without manual registration.
• Declarative site column overrides — [SiteColumn] attribute supports column name, max length, required constraint, default value, column type, and ignore (exclude from mapping).
• UPPER_SNAKE_CASE convention — SiteColumnExtensions.ApplySiteColumnOverrides applies UPPER_SNAKE_CASE to all unmapped properties automatically, keeping convention consistent with the Dapper/ISiteColumnMap layer.
• Shared naming convention — ToUpperSnakeCase delegates to ColumnNamingConvention.ToUpperSnakeCase from Muonroi.Core.Abstractions, the single source of truth for column naming across EF Core and Dapper.

Configuration

No DI registration is required. MEntityConfigurationBase<TEntity> is consumed by EF Core's model-building pipeline directly. ApplySiteColumnOverrides is called inside DbContext.OnModelCreating.

API Reference

Samples

• TestProject.Service — demonstrates [SiteColumn] attribute on BravoOrder and ApplySiteColumnOverrides wired in a minimal DbContext.
• TestProject.Service.IntegrationTests — xUnit tests verifying [SiteColumn] attribute inspection and ApplySiteColumnOverrides column mapping via the EF Core in-memory provider.

Compatibility

• Target framework: net8.0
• License: Apache-2.0 (OSS)

Related Packages

• Muonroi.Core.Abstractions — provides ColumnNamingConvention.ToUpperSnakeCase, the shared naming source used by this package.
• Muonroi.Data.EntityFrameworkCore — the higher-level EF Core package (MDbContext, audit timestamping, soft-delete). Use MEntityConfigurationBase<TEntity> inside a MDbContext subclass for the full stack.

License

Apache-2.0. See LICENSE-APACHE at the repository root.