Phalanger, PHP for .NET: Introduction for .NET developers

using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;

namespace DemoDataLayer
{
	/// <summary>
	/// Represenets product that has ID, Name and Price
	/// </summary>
	public class Product
	{
		#region Members

		private int id;
		public int ID { get { return id; } }
	
		private string name;
		public string Name { get { return name; } set { name = value; } }

		private double price;
		public double Price { get { return price; } set { price = value; } }

		public Product(int id, string name, double price)
		{
			this.id = id; this.name = name; this.price = price;
		}

		#endregion
	}

	/// <summary>
	/// Represents category with ID, Name and web page theme
	/// </summary>
	public class Category
	{
		#region	Members

		private string theme;
		public string Theme { get { return theme; } set { theme = value; } }
	
		private int id;
		public int ID { get { return id;} }

		private string name;
		public string Name { get { return name;} set { name = value;} }

		public Category(int id, string name, string theme)
		{
			this.id = id; this.name = name; this.theme = theme;
		}

		#endregion
	}

	/// <summary>
	/// Access to data (data are stored in memory)
	/// </summary>
	public class Data
	{
		#region Configuration

		const string connStr = "Server=.;Database=Northwind;Integrated Security=Yes;";

		#endregion
		#region Members

		public List<Category> GetCategories()
		{
			List<Category> ret = new List<Category>();
			using(SqlConnection cn = new SqlConnection(connStr))
			{
				cn.Open();
				SqlCommand cmd = new SqlCommand("SELECT [CategoryID], [CategoryName] FROM [Categories]", cn);
				using (SqlDataReader reader = cmd.ExecuteReader())
				{
					while (reader.Read())
					{
						ret.Add(new Category((int)reader["CategoryID"], (string)reader["CategoryName"],
							GetTheme((int)reader["CategoryID"])));
					}
				}
			}
			return ret;
		}

		public Category GetCategory(int id)
		{
			using (SqlConnection cn = new SqlConnection(connStr))
			{
				cn.Open();
				SqlCommand cmd = new SqlCommand(string.Format("SELECT TOP 1 [CategoryID], [CategoryName] FROM "+
					"[Categories] WHERE [CategoryID]={0}", id), cn);
				using (SqlDataReader reader = cmd.ExecuteReader())
				{
					if (reader.Read())
						return new Category((int)reader["CategoryID"], (string)reader["CategoryName"], GetTheme((int)reader["CategoryID"]));
				}
			}
			return null;
		}

		public List<Product> GetProducts(int category)
		{
			List<Product> ret = new List<Product>();
			using (SqlConnection cn = new SqlConnection(connStr))
			{
				cn.Open();
				SqlCommand cmd = new SqlCommand(string.Format("SELECT [ProductID], [ProductName], [UnitPrice] FROM [Products] "+
					"WHERE [CategoryID]={0}", category), cn); // this is ok for integers
				using (SqlDataReader reader = cmd.ExecuteReader())
				{
					while (reader.Read())
					{
						ret.Add(new Product((int)reader["ProductID"], (string)reader["ProductName"], (double)(decimal)reader["UnitPrice"]));
					}
				}
			}
			return ret;
		}

		public Product GetProduct(int id)
		{
			List<Product> ret = new List<Product>();
			using (SqlConnection cn = new SqlConnection(connStr))
			{
				cn.Open();
				SqlCommand cmd = new SqlCommand(string.Format("SELECT [ProductID], [ProductName], [UnitPrice] FROM [Products] " +
					"WHERE [ProductID]={0}", id), cn); // this is ok for integers
				using (SqlDataReader reader = cmd.ExecuteReader())
				{
					if (reader.Read())
						return new Product((int)reader["ProductID"], (string)reader["ProductName"], (double)(decimal)reader["UnitPrice"]);
				}
			}
			return null;
		}

		private string GetTheme(int p)
		{
			switch (p)
			{
				case 1:
				case 5:
				case 6: return "green"; // food&drinks
				default: return "default"; // other
			}
		}

		#endregion
	}
}