Entity Framework Sandbox Template

Overview

With the recent GA launch of EF7 (i.e. EF Core 7), I thought I'd roll up my sleeves and try out some of the new features. However, to do this I would need a basic EF7 setup, running in an application, and pointing to a database populated with some data.

I wanted to keep things simple so I started with a console application, created several entities, enabled migrations and ensured it had some seed data. As I started looking at the EF configuration required to test the new features, it became clear to me that I would need a different DB Model and EF setup for each example.

This lead me to the idea, that perhaps it would be useful to create a template that enabled a populated EF project to be rapidly created.

Entity Framework Sandbox Template

The Entity Framework Sandbox is a CLI project template that allows you to quickly spin up a functioning project running on the latest version of EF with a real database and real data.

This can be useful in the following scenarios:

• Exploring new features of EF such as
• Safely exploring changes to a real application
• Replicating EF issues in an isolated environment

This is intended to be a tool to help you learn EF. It is not intended to be a starting point for a production application.

Features

The template includes the following:

• CLI command for creating a new solution
• Blog/Post/Tag entities
• Migrations and seed data
• Logging of generated SQL
• Model configuration
• Placeholders for running commands and queries

Setup

Template Installation

Install the dotnet CLI template via:

dotnet new --install EntityFrameworkSandbox.Template

Project Creation

You can use the template to create a new project via:

mkdir my-ef-sandbox
cd my-ef-sandbox
dotnet new ef-sandbox

Alternatively, you can create the project directly into a new sub-folder via:

dotnet new ef-sandbox --name my-sub-folder

Usage

Writing Commands & Queries

• Ensure the connection matches if you are using something other than local DB
• Update the Sandbox to run your own EF queries and commands

private async Task RunQueries()
{
    // NOTE: Further DB queries go here
}

private Task RunCommands()
{
    // NOTE: Further DB commands go here
}

Overriding Model Configuration

This can be done in the configuration classes:

internal class PostConfiguration : IEntityTypeConfiguration<Post>
{
    public void Configure(EntityTypeBuilder<Post> builder)
    {
        // NOTE: Custom model configuration goes here
    }
}

Schema Changes

The project is designed to use migrations for schema upgrades. However, if you prefer to instead drop and create the DB every time you can set Application.EnableMigrations to false in appsettings.json:

"Application": {
    "EnableMigrations": false
}

Running the Project

Pressing F5 or running dotnet run will cause the following to happen:

• Console will start
• By default, DB will be dropped & re-created
• Data will be seeded
• SQL queries will run
• All SQL and results output to the console

Summary

In this article, I have shown some of the reasons that a sandbox may be useful for EF7. I have shown how to install the template, use the CLI command, and how to use the template to test commands, queries, and model configuration.

Let me know if you find this useful, or have any suggestions for improvements. Better yet, for the repo and submit a pull request.

Now it's back to learning all the awesome new features of EF7. 😎

References

• EF7 Announcement
• dotnet-ef-sandbox