DbContext class separated.

code/MessengerBroker.Db.Sql/BrokerSqlDbContext.cs

@@ -0,0 +1,20 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace MessengerBroker.Db.Sql
+{
+    public class BrokerSqlDbContext : BrokerDbContext
+    {
+        private readonly string connectionString;
+
+        public BrokerSqlDbContext(string connectionString)
+        {
+            this.connectionString = connectionString;
+        }
+
+        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+        {
+            base.OnConfiguring(optionsBuilder);
+            optionsBuilder.UseSqlServer(this.connectionString);
+        }
+    }
+}

code/MessengerBroker.Db.Sql/MessengerBroker.Db.Sql.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="9.0.6" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\MessengerBroker.Db\MessengerBroker.Db.csproj" />
+  </ItemGroup>
+
+</Project>

code/MessengerBroker.Db/BrokerDbContext.cs

@@ -5,28 +5,10 @@ namespace MessengerBroker.Db
 {
     public class BrokerDbContext : DbContext
     {
-        private string connectionString;
-
         public DbSet<Sync> Syncs { get; }
 
         public DbSet<User> Users { get; }
 
         public DbSet<Message> Messages { get; }
-
-        public BrokerDbContext(string connectionString)
-        {
-            this.connectionString = connectionString;
-        }
-
-        protected override void OnModelCreating(ModelBuilder modelBuilder)
-        {
-            base.OnModelCreating(modelBuilder);
-        }
-
-        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
-        {
-            base.OnConfiguring(optionsBuilder);
-            optionsBuilder.UseSqlServer(this.connectionString);
-        }
     }
 }

code/MessengerBroker.Db/MessengerBroker.Db.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <TargetFramework>net9.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
-    <Nullable>enable</Nullable>
+    <Nullable>disable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

code/MessengerBroker.Db/Model/Contracts/IForeignEntity.cs

@@ -1,15 +0,0 @@
-namespace MessengerBroker.Db.Model.Contracts
-{
-    public interface IForeignEntity
-    {
-        Guid Id { get; }
-
-        Guid BrokerId { get; }
-
-        bool IsDeleted { get; }
-
-        Sync? FirstSync { get; }
-
-        Sync? LastSync { get; }
-    }
-}

code/MessengerBroker.Db/Model/User.cs

@@ -1,6 +1,4 @@
-using MessengerBroker.Db.Model.Contracts;
-
-namespace MessengerBroker.Db.Model
+namespace MessengerBroker.Db.Model
 {
     public class User
     {