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>