Create abstract database schema

src/Giveaways.Data/Models/KeyedEntity.cs

@@ -0,0 +1,28 @@
+using System;
+using Discord;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace Giveaways.Data;
+
+/// <summary>
+/// Represents an abstract class for entities with a key identifier.
+/// </summary>
+/// <typeparam name="TId">The type of the key identifier.</typeparam>
+public abstract class KeyedEntity<TId> : IEntity<TId>
+    where TId : IEquatable<TId>
+{
+    public TId Id { get; init; } = default!;
+}
+
+/// <summary>
+/// Represents an abstract class for configuring entities with a key identifier.
+/// </summary>
+/// <typeparam name="TId">The type of the key identifier.</typeparam>
+/// <typeparam name="TEntity">The type of the entity.</typeparam>
+internal abstract class KeyedEntityConfiguration<TId, TEntity> : IEntityTypeConfiguration<TEntity>
+    where TId : IEquatable<TId>
+    where TEntity : KeyedEntity<TId>
+{
+    public abstract void Configure(EntityTypeBuilder<TEntity> builder);
+}