csharp Dapper.Rainbow.cs

Posted 2021-05-12

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

using Dapper;

// to have a play, install Dapper.Rainbow from nuget

namespace TestDapper
{
    class Program
    {
        // no decorations, base class, attributes, etc 
        class Product 
        {
            public int Id { get; set; }
            public string Name { get; set; }
            public string Description { get; set; }
            public DateTime? LastPurchase { get; set; }
        }

        // container with all the tables 
        class MyDatabase : Database<MyDatabase>
        {
            public Table<Product> Products { get; set; }
        }

        static void Main(string[] args)
        {
            var cnn = new SqlConnection("Data Source=.;Initial Catalog=tempdb;Integrated Security=True");
            cnn.Open();

            var db = MyDatabase.Init(cnn, commandTimeout: 2);

            try
            {
                db.Execute("waitfor delay '00:00:03'");
            }
            catch (Exception)
            {
                Console.WriteLine("yeah ... it timed out");
            }


            db.Execute("if object_id('Products') is not null drop table Products");
            db.Execute(@"create table Products (
                    Id int identity(1,1) primary key, 
                    Name varchar(20), 
                    Description varchar(max), 
                    LastPurchase datetime)");

            int? productId = db.Products.Insert(new {Name="Hello", Description="Nothing" });
            var product = db.Products.Get((int)productId);

            product.Description = "untracked change";

            // snapshotter tracks which fields change on the object 
            var s = Snapshotter.Start(product);
            product.LastPurchase = DateTime.UtcNow;
            product.Name += " World";
            
            // run: update Products set LastPurchase = @utcNow, Name = @name where Id = @id
            // note, this does not touch untracked columns 
            db.Products.Update(product.Id, s.Diff());

            // reload
            product = db.Products.Get(product.Id);
            

            Console.WriteLine("id: {0} name: {1} desc: {2} last {3}", product.Id, product.Name, product.Description, product.LastPurchase);
            // id: 1 name: Hello World desc: Nothing last 12/01/2012 5:49:34 AM

            Console.WriteLine("deleted: {0}", db.Products.Delete(product.Id));
            // deleted: True 


            Console.ReadKey();
        }
    }
}