kolosovpetro / codefirstentityframeworkcore

Simple example of Entity Framework Core Code-First approach.

Code First with Entity Framework

Simple example of Entity Framework Core Code-First approach.

Data base schema

Required packages and settings

Nuget Packages:

• Microsoft.EntityFrameworkCore
• Microsoft.EntityFrameworkCore.Tools
• Microsoft.EntityFrameworkCore.SqlServer
• Npgsql.EntityFrameworkCore.PostgreSQL

Settings:

• Environmental variable: SQLSERVER_MOVIES_LOCAL_CONNSTR
• Environmental variable: POSTGRES_MOVIES_LOCAL_CONNSTR

Entity Framework CLI commands

Postgres:

• dotnet-ef migrations add PostgreSqlInitialMigration --project CodeFirst.DataAccess --context PostgresDbContext
• dotnet-ef database update --project CodeFirst.DataAccess --context PostgresDbContext
• dotnet-ef database drop --project CodeFirst.DataAccess --context PostgresDbContext

MS SQL Server:

• dotnet-ef migrations add SqlServerInitialMigration --project CodeFirst.DataAccess --context SqlServerDbContext
• dotnet-ef database update --project CodeFirst.DataAccess --context SqlServerDbContext
• dotnet-ef database drop --project CodeFirst.DataAccess --context PostgresDbContext

How to code first?

• Create a separate project Models, where data models are stored.

• Create a separate project DataAccess, that is responsible for interaction with database.

• Load packages to DataAccess project. See section Required packages.

• Set proper environmental variable for connection string for SQL Server database. For localhost it is:

  "Data Source=DESKTOP-RN0NICT;Initial Catalog=MoviesCodeFirst;Integrated Security=true;"

• Set proper environmental variable for connection string for Postgre SQL database. For localhost it is:

  "Server=localhost;User Id=postgres;Password=postgres;Database=MoviesCodeFirst;"

• Build a relations between models, for instance, one-to-one, one-to-many, many-to-many according to the database diagram. Refer to

  • https://www.learnentityframeworkcore.com/configuration/one-to-one-relationship-configuration
  • https://www.learnentityframeworkcore.com/relationships/managing-one-to-many-relationships
  • https://www.learnentityframeworkcore.com/configuration/many-to-many-relationship-configuration

• Create proper configurations of models, using Fluent API. Configuration should implement IEntityTypeConfiguration<T> interface from Entity Framework namespace

• Create BaseContext inherrit it from DbContext in Entity Framework namespace, add related sets BDSet<T>, where T -- models.

• Create SqlServerContext, inherrit it from BaseContext and override methods OnConfiguring and OnModelCreating.

• Create PostgreSqlContext, inherrit it from BaseContext and override methods OnConfiguring and OnModelCreating.

• Create migration for SqlServerContext, use CLI command:

  dotnet-ef migrations add SqlServerInitialMigration --project CodeFirst.DataAccess --context SqlServerDbContext

• Create migration for PostgreSqlContext, use CLI command:

  dotnet-ef migrations add PostgreSqlInitialMigration --project CodeFirst.DataAccess --context PostgresDbContext

• Update SQL Server database, use CLI command:

  dotnet-ef database update --project CodeFirst.DataAccess --context SqlServerDbContext

• Update Postgre SQL database, use CLI command:

  dotnet-ef database update --project CodeFirst.DataAccess --context PostgresDbContext

• Write unit tests for SqlServerDbContext

• Write unit tests for PostgresDbContext

• Create Generic repository interface

• Implement Generic repository interface

• Test Generic Repositories

Notes

To get MS SQL connection string proceed:

• Go to visual studio - Server explorer - Data connections
• Right click on data connections - Add new connection
• Type there your server name
• Click add connection
• Then in properties of such connection you'd get connection string

codefirstentityframeworkcore's Issues

Add regions on the entities' relationships in config files

Add regions on the entities' relationships in config files

Add Cascade delete to configurations

Add Cascade delete to configurations

Write tests for repositories

Write tests for repositories

Highlight commands in README

Highlight commands in README