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Dapper & Micro-ORMs

When to Use Dapper​

  • Complex queries
  • Performance-critical operations
  • Stored procedures
  • Reporting queries

Basic Usage​

using Dapper;

var products = await connection.QueryAsync<Product>(
    "SELECT * FROM Products WHERE Price > @MinPrice",
    new { MinPrice = 100 });

Multi-Mapping​

var orders = await connection.QueryAsync<Order, Customer, Order>(
    "SELECT * FROM Orders o INNER JOIN Customers c ON o.CustomerId = c.Id",
    (order, customer) =>
    {
        order.Customer = customer;
        return order;
    },
    splitOn: "Id");

Dapper vs EF Core​

FeatureDapperEF Core
PerformanceFasterGood
FlexibilityHighMedium
Learning CurveLowHigher
Change TrackingNoYes
MigrationsNoYes

Connection Pooling​

// Automatic in ASP.NET Core
builder.Services.AddDbContext<AppDbContext>(options =>
    options.UseSqlServer(connectionString));

Response Compression​

builder.Services.AddResponseCompression(options =>
{
    options.EnableForHttps = true;
});

app.UseResponseCompression();

Async/Await Best Practices​

// ✅ Good
public async Task<List<Product>> GetProductsAsync()
{
    return await _context.Products.ToListAsync();
}

// ❌ Bad - Blocking
public List<Product> GetProducts()
{
    return _context.Products.ToList();
}

Use DTOs​

// Don't return entities directly
public record ProductDto(int Id, string Name, decimal Price);