• 分享一个灰常好的 dapper 扩展插件: Rainbow


      dapper 是一个效率非常高的orm  框架 ,效率要远远大于 我们大微软的EF .    它只有一个类文件,非常之小。(在 EF 5.0 后 微软已经做了 改进)

       ps; 由于之前我也没测试过,只是看过官方之前的数据,还是实践出真知 。 在这里谢谢 深蓝医生 的指正。不过它还是一个非常优秀的微型orm框架。

       1,首先下载dapper  这里下载   .

       2,下载插件  Rainbow

        在Package Manager Console  中输入

    PM> Install-Package Dapper.Rainbow 

      

      准备工作 完成  下面是 demo 。

    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();
            }
        }
    }
    

      

    上面 这个MyDatabase ,实现了和 EF同样的机制 ,有了这个相当于EF 上下文的东西,就方便很多了, 拿到这个上下文后,就能直接操作所有的表了 ,方便了统一管理  ,用着很爽呀。。  .

      

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  • 原文地址:https://www.cnblogs.com/DiscoverPalace/p/3420592.html
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