Using

install to the project nuget library:

dotnet add package Microsoft.EntityFrameworkCore

dotnet add package Npgsql.EntityFrameworkCore.PostgreSQL

dotnet add package Microsoft.EntityFrameworkCore.Design

dotnet add package MyJetWallet.Sdk.Postgres

Create DbContext. NEED INHERITE MyDbContext!

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

        public string Text { get; set; }
    }

    public class MyContext: MyDbContext
    {
        public const string Schema = "myschema";
        public const string MyDbTableName = "mydbtable"

        public DbSet<MyDbEntity> MyDbEntity { get; set; }

        public MyContext(DbContextOptions options) : base(options)
        {
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.HasDefaultSchema(Schema);

            modelBuilder.Entity<MyDbEntity>().ToTable(MyDbTableName);
            modelBuilder.Entity<MyDbEntity>().Property(e => e.Id).UseIdentityColumn();
            modelBuilder.Entity<MyDbEntity>().HasKey(e => e.Id);
            modelBuilder.Entity<MyDbEntity>().Property(e => e.Text).HasMaxLength(1024);
            
            base.OnModelCreating(modelBuilder);
        }
    }

Setup class to DesignTime connect to the database. The class will auto-used for the creating migration.

    public class ContextFactory : MyDesignTimeContextFactory<MyContext>
    {
        public ContextFactory() : base(options => new MyContext(options))
        {
        }
    }

Register database into the services

    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            MyContext.LoggerFactory = Program.LoggerFactory;
            services.AddDatabase(MyContext.Schema, ConnectionString, o => new MyContext(o));  
            MyContext.LoggerFactory = null;
        }
    }

Using cotext into the code

    [ApiController]
    [Route("[controller]")]
    public class MyTestController : ControllerBase
    {
        private readonly DbContextOptionsBuilder<MyContext> _dbContextOptionsBuilder;

        public WeatherForecastController(DbContextOptionsBuilder<MyContext> dbContextOptionsBuilder)
        {
            _dbContextOptionsBuilder = dbContextOptionsBuilder;
        }

        [HttpGet("data")]
        public IEnumerable<MyTable> GetData()
        {
            using var ctx = new MyContext(_dbContextOptionsBuilder.Options);
            var data = ctx.MyTable.ToList();
            return data;
        }
    }

Create migration

dotnet ef migrations add Migration_Name

Build started...
Build succeeded.
Connection string: <Print connection string to the databse where need to create migration>

after migration created, migration will stored in the folder Migrations

After the start, the application will check the database. And if migration missed then automatically execute migration in the database.

More detail you can read here: https://docs.microsoft.com/en-us/ef/core/cli/dotnet

Min value for DateTime

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.HasDefaultSchema(Schema);

    modelBuilder.Entity<MyDbEntity>().ToTable(MyDbTableName);
    modelBuilder.Entity<MyDbEntity>().Property(e => e.Time).HasDefaultValue(DateTime.MinValue);

    base.OnModelCreating(modelBuilder);
}