C#BlogDbContext.cs
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using Microsoft.EntityFrameworkCore;
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using Microsoft.EntityFrameworkCore.Metadata.Builders;
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public class BlogDbContext : DbContext
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{
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    public DbSet<Blog> Blogs => Set<Blog>();
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    public DbSet<Post> Posts => Set<Post>();
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    public BlogDbContext(DbContextOptions<BlogDbContext> options) : base(options) { }
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    protected override void OnModelCreating(ModelBuilder modelBuilder)
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    {
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        modelBuilder.ApplyConfiguration(new BlogConfiguration());
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        modelBuilder.ApplyConfiguration(new PostConfiguration());
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    }
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}
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public class Blog
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{
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    public int Id { get; set; }
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    public string Title { get; set; } = default!;
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    public string Url { get; set; } = default!;
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    public List<Post> Posts { get; set; } = [];
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}
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public class Post
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{
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    public int Id { get; set; }
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    public string Title { get; set; } = default!;
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    public string Content { get; set; } = default!;
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    public int BlogId { get; set; }
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    public Blog Blog { get; set; } = default!;
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    public DateTime PublishedAt { get; set; }
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}
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public class BlogConfiguration : IEntityTypeConfiguration<Blog>
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{
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    public void Configure(EntityTypeBuilder<Blog> builder)
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    {
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        builder.HasKey(b => b.Id);
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        builder.Property(b => b.Title).IsRequired().HasMaxLength(200);
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        builder.Property(b => b.Url).IsRequired().HasMaxLength(500);
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        builder.HasIndex(b => b.Url).IsUnique();
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        builder.HasMany(b => b.Posts)
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               .WithOne(p => p.Blog)
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               .HasForeignKey(p => p.BlogId)
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               .OnDelete(DeleteBehavior.Cascade);
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    }
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}
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public class PostConfiguration : IEntityTypeConfiguration<Post>
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{
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    public void Configure(EntityTypeBuilder<Post> builder)
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    {
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        builder.HasKey(p => p.Id);
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        builder.Property(p => p.Title).IsRequired().HasMaxLength(300);
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        builder.HasIndex(p => p.PublishedAt);
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    }
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}
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// Query helpers
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public class BlogQueryService
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{
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    private readonly BlogDbContext _db;
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    public BlogQueryService(BlogDbContext db) => _db = db;
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    public async Task<List<Blog>> GetBlogsWithRecentPostsAsync(CancellationToken ct = default)
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    {
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        return await _db.Blogs
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            .AsNoTracking()
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            .Include(b => b.Posts.OrderByDescending(p => p.PublishedAt).Take(5))
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            .AsSplitQuery()
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            .ToListAsync(ct);
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    }
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}
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