devel0 / skeleton-netcore-ef-code-first

entity core code-first from console app

skeleton-netcore-ef-code-first

• description
• prepare database context
• managing migrations
  • first migrations
  • update database
• run the app
• migration tool summary
• clean architecture
• how this project was built

👉 one-to-one, one-to-many, many-to-many code first relationship examples here

description

Shows how to create a code-first local db using sqlite but the same approach can applied using other backends.

prepare database context

• add nuget pkg of EntityFrameworkCore.Design and for specific backend used
• create table as code first
• create db context
  • override OnConfiguring where setup specific backend used
  • override OnModelCreating where table fields can be configured ( primary keys, indexes, ... ) or seeding of initial data can be added
  • create a dataset foreach of the table wants to be materialized on the db

managing migrations

Migrations in code-first db allow team of developers to work on the same db project each with their on local db and versioning their changes through commits that includes Migrations folder.

The first-est migration is done by a developer and acts as an entry point for the work on that database so other developers can add their code-first changes after that commit by adding further migrations including code and Migrations folder changes.

Because each migration has a timestamp in the filename there aren't conflict on these while the Migrations/LocalDbContextModelSnapshots.cs can be subjected to normal git conflicts in some circumnstances that can be resolved in the usual way. To reduce conflict situation, regular pulls could help.

first migrations

Install dotnet ef migrations tools:

dotnet tool install --global dotnet-ef

Create initial migration:

cd skeleton-netcore-ef-core-first
dotnet ef migrations add initial

Commit the initial migration ( I didn't added the initial migration for didactic purpose ).

update database

Create a migration doesn't imply the code-first materialize on database, in order to do that, issue:

dotnet ef database update

This command can be used also to revert a migration applied by specifying a name of a migration already applied and all migrations after that one specified will be reverted returning to a state of "pending".

Migrations can be removed, when are in pending state, one by one from tail using dotnet ef migrations remove.

run the app

dn run
Started with 0 records
add new one [newRecord1]
changes: SampleData {Id: -9223372036854774807} Added

migration tool summary

cmd	description
dotnet ef migrations list	list migrations showing which aren't yet applied (pending)
dotnet ef database update	apply pending migrations
dotnet ef migrations add MIGRATION_NAME	add migrations
dotnet ef migrations remove	remove latest not yet committed migration
dotnet ef databse update MIGRATION_TO	revert applied migration

clean architecture

To improve maintainability, modularity and separation of concerns in enterprise applications the Clean architecture should evaluated; there are many boiler plate templates available:

dotnet new search clean

how this project was built

dotnet new console -n skeleton-netcore-ef-code-first -f net7.0 --langVersion 11

cd skeleton-netcore-ef-code-first
dotnet add package Microsoft.EntityFrameworkCore.Design --version 7.0.5
dotnet add package Microsoft.EntityFrameworkCore.Sqlite --version 7.0.5