Add receiver (not complete)

Samples/SampleModbusRtuServer/DatabaseWrite.cs

@@ -0,0 +1,34 @@
+using Microsoft.EntityFrameworkCore;
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace MachineJob
+{
+    public class DatabaseWriteContext : DbContext
+    {
+        private static readonly IConfigurationRoot configuration = new ConfigurationBuilder()
+            .SetBasePath(Directory.GetCurrentDirectory())
+            .AddJsonFile("appsettings.default.json", optional: false, reloadOnChange: true)
+            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
+            .AddJsonFile($"appsettings.{Environment.GetEnvironmentVariable("DOTNET_ENVIRONMENT") ?? Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") ?? "Production"}.json", optional: true, reloadOnChange: true)
+            .Build();
+
+        private static readonly string connectionString = configuration.GetConnectionString("DatabaseWriteConnectionString")!;
+
+        public DbSet<DatabaseWriteEntity>? DatabaseWrites { get; set; }
+
+        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+        {
+            optionsBuilder.UseMySql(connectionString, ServerVersion.AutoDetect(connectionString));
+        }
+    }
+
+    [Table(name: "databasewrites")]
+    public partial class DatabaseWriteEntity
+    {
+        [Key]
+        public int Id { get; set; }
+
+        public DateTime UpdateTime { get; set; }
+    }
+}