Toolbelt.EntityFrameworkCore.IndexAttribute.Attribute 1.0.0

IndexAttribute for EntityFramework Core

What's this?

Revival of [Index] attribute for EF Core. (with extension for model building.)

Attention

EF Core team said:

"We didn't bring this (= IndexAttribute) over from EF6.x because it had a lot of issues"
(https://github.com/aspnet/EntityFrameworkCore/issues/4050)

Therefore, you should consider well before use this package.

How to use?

1. Add Toolbelt.EntityFrameworkCore.IndexAttribute package to your project.

> dotnet add package Toolbelt.EntityFrameworkCore.IndexAttribute

2. Annotate your model with [Index] attribute that lives in Toolbelt.ComponentModel.DataAnnotations.Schema namespace.

using Toolbelt.ComponentModel.DataAnnotations.Schema;

public class Person
{
    public int Id { get; set; }

    [Index] // <- Here!
    public string Name { get; set; }
}

3. [Important] Override OnModelCreating() method of your DbContext class, and call BuildIndexesFromAnnotations() extension method which lives in Toolbelt.ComponentModel.DataAnnotations namespace.

using Microsoft.EntityFrameworkCore;
using Toolbelt.ComponentModel.DataAnnotations;

public class MyDbContext : DbContext
{
    ...
    // Override "OnModelCreating", ...
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        // .. and invoke "BuildIndexesFromAnnotations"!
        modelBuilder.BuildIndexesFromAnnotations();
    }
}

That's all!

BuildIndexesFromAnnotations() extension method scans the DbContext with .NET Reflection technology, and detects [Index] attributes, then build models related to indexing.

After doing that, the database which created by EF Core, contains indexes that are specified by [Index] attributes.

For More Detail...

This library is designed to have the same syntax as EF 6.x [Index] annotation.

Please visit document site of EF 6.x and [Index] attribute for EF 6.x.

• MSDN Document - Entity Framework Code First Data Annotations
• MSDN Document - IndexAttribute class

Not Supported Feature

IsClustered property is not supported at this version.

Appendix

If you want to use only "IndexAttribute" without any dependencies...

If you want to use only "IndexAttribute" class without any dependencies, you can use Toolbelt.EntityFrameworkCore.IndexAttribute.Attribute NuGet package.

License

MIT License