用NetCore 和Dapper 和mySql做一个简单的实例，
一准备工作
1：VS2017+windos系统，也可以用其他的操作系统和工具
2：一台Cenetos的虚拟机或者虚拟机
二：开始
1：用微软官方的netCore的ToDo项目改造，项目的主体结构如下图，源连接
https://docs.microsoft.com/zh-cn/aspnet/core/tutorials/first-web-api
1：打开Nuget控制台，安装 MySQL官方.NET Core驱动,并且支持 EF Core
>Install-Package SapientGuardian.MySql.Data -Pre
2：打开Nuget控制台，安装Dapper
>Install-Package Dapper -Pre
3：在Models文件夹下新建ToDoItem 的实体
public class ToDoItem{[Required]public string ID { get; set; }[Required]public string Name { get; set; }[Required]public string Notes { get; set; }public bool Done { get; set; }}
4：在appsettings.json里面配置MySql的数据库连接字符串，然后点开appsettings.json的属性将“复制到输出目录”项的值改为“始终复制”，
SslMode=none的作用是解决连接的时候报SSL错误的 "ConnectionStrings": {"SqlServerConnection": "Server=(LocalDb)\\MSSQLLocalDB, Database=test","MySqlConnection": "Server=自己的服务器;Database=test;User ID=root;Password=111111;SslMode=none"}
5：在Common下面新建一个AppConfigurtaionServices的类，用于读取appsettings.json里面的连接字符串(appsettings.json属性如果没有选中始终复制，在代码运行的时候，
IConfiguration 会报错)
public class AppConfigurtaionServices{public static IConfiguration Configuration { get; set; }static AppConfigurtaionServices(){Configuration = new ConfigurationBuilder().Add(new JsonConfigurationSource { Path = "appsettings.json", ReloadOnChange = true }).Build();}}
6：新建一个Interfaces文件夹，然后下面建一个IToDoRepository的接口类
public interface IToDoRepository{bool DoesItemExist(string id);IEnumerable<ToDoItem> All();ToDoItem Find(string id);int Insert(ToDoItem item);int Update(ToDoItem item);int Delete(string id);}
7：新建一个Services然后下面新建ToDoRepository类 是我们的数据仓储类 记得要引用(using Dapper;和 using MySql.Data.MySqlClient;)
public class ToDoRepository : IToDoRepository{private static string DefaultSqlConnectionString = "";public ToDoRepository(){DefaultSqlConnectionString = AppConfigurtaionServices.Configuration.GetConnectionString("MySqlConnection"); }public static IDbConnection GetSqlConnection(string sqlConnectionString = null){if (string.IsNullOrWhiteSpace(sqlConnectionString)){sqlConnectionString = DefaultSqlConnectionString;}IDbConnection conn = new MySqlConnection(sqlConnectionString);conn.Open();return conn;}/// <summary>/// 获取全部/// </summary>/// <returns></returns>public IEnumerable<ToDoItem> All(){using (IDbConnection conn = GetSqlConnection()){string strsql = "select * from ToDoItem";return conn.Query<ToDoItem>(strsql, null);}}/// <summary>/// 查询是否存在/// </summary>/// <param name="id"></param>/// <returns></returns>public bool DoesItemExist(string id){using (IDbConnection conn = GetSqlConnection()){int cout = conn.Query<int>("select count(*) from ToDoItem where ID=@ID", new { ID = id }).FirstOrDefault();if (cout > 0)return true;elsereturn false;}}/// <summary>/// 删除/// </summary>/// <param name="id"></param>/// <returns></returns>public int Delete(string id){using (IDbConnection conn = GetSqlConnection()){string strsql = "DELETE from ToDoItem where ID=@ID";return conn.Execute(strsql, new { ID = id });}}/// <summary>/// 查询整个对象/// </summary>/// <param name="id"></param>/// <returns></returns>public ToDoItem Find(string id){using (IDbConnection conn = GetSqlConnection()){string strsql = "select * from ToDoItem where ID=@ID";return conn.Query<ToDoItem>(strsql, new { ID = id }).FirstOrDefault();}}/// <summary>/// 新增项/// </summary>/// <param name="item"></param>/// <returns></returns>public int Insert(ToDoItem item){using (IDbConnection conn = GetSqlConnection()){string strsql = "INSERT into ToDoItem(ID,Name,Notes,Done)values(@ID,@Name,@Notes,@Done)";return conn.Execute(strsql, item);}}/// <summary>/// 修改/// </summary>/// <param name="item"></param>/// <returns></returns>public int Update(ToDoItem item){using (IDbConnection conn = GetSqlConnection()){string strsql = " UPDATE ToDoItem SET Name=@Name,Notes=@Notes,Done=@Done where ID=@ID";return conn.Execute(strsql, item);}}}
8：在Controller下面新增一个ToDoItemsController的控制器，记得添加相关的命名空间
[Route("api/[controller]")]public class ToDoItemsController : Controller{private readonly IToDoRepository _toDoRepository;public ToDoItemsController(IToDoRepository toDoRepository){_toDoRepository = toDoRepository;}/// <summary>/// 获取数据/// </summary>/// <returns></returns>[HttpGet]public IActionResult List(){return Ok(_toDoRepository.All());}/// <summary>/// 新增项/// </summary>/// <param name="item"></param>/// <returns></returns>[HttpPost]public IActionResult Create([FromBody] ToDoItem item){try{if (item == null || !ModelState.IsValid){return BadRequest("没有通过验证");}bool itemExists = _toDoRepository.DoesItemExist(item.ID);if (itemExists){return StatusCode(StatusCodes.Status409Conflict, "已经存在此项");}_toDoRepository.Insert(item);}catch (Exception){return BadRequest("创建失败");}return Ok(item);}/// <summary>/// 修改项/// </summary>/// <param name="item"></param>/// <returns></returns>[HttpPut]public IActionResult Edit([FromBody] ToDoItem item){try{if(item==null || !ModelState.IsValid)return BadRequest("没有通过必填验证");var existingItem = _toDoRepository.Find(item.ID);if(existingItem==null){return NotFound("没有发现此记录");}_toDoRepository.Update(item);}catch(Exception){return BadRequest("修改失败");}return NoContent();}/// <summary>/// 删除/// </summary>/// <param name="id"></param>/// <returns></returns>[HttpDelete("{id}")]public IActionResult Delete(string id){try{var item = _toDoRepository.Find(id);if (item == null)return NotFound("没有此记录");_toDoRepository.Delete(id);}catch(Exception ){return BadRequest("删除失败");}return NoContent();}}
9：在ConfigureServices里配置IToDoRepository 和ToDoRepository服务
services.AddSingleton<IToDoRepository, Services.ToDoRepository>();
10：配置Swagger(丝袜哥)具体Swagger的基础知识可以连接到
https://docs.microsoft.com/zh-cn/aspnet/core/tutorials/web-api-help-pages-using-swagger?tabs=visual-studio
10.1：在Nuget控制台添加引用
>Install-Package Swashbuckle.AspNetCore
10.2:在Startup类中配置Swagger
10.2.1：在ConfigureServices方法里面添加Swagger服务
//添加Swagger服务services.AddSwaggerGen(c =>{c.SwaggerDoc("v1", new Info{Version = "v1",Title = "ToDo API",Description = "A simple example ASP.NET Core Web API",TermsOfService = "None",Contact = new Contact { Name = "Shayne Boyer", Email = "", Url = "https://twitter.com/spboyer" },License = new License { Name = "Use under LICX", Url = "https://example.com/license" }});var basePath = PlatformServices.Default.Application.ApplicationBasePath;var xmlPath = Path.Combine(basePath, "ToDoApi.xml");c.IncludeXmlComments(xmlPath);});
10.2.2：在Configure配置Swagger服务
app.UseSwagger();
//配置Swagger服务
app.UseSwaggerUI(c =>
{c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
});
10.3：最终的Startup类如下
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.PlatformAbstractions;
using Swashbuckle.AspNetCore.Swagger;
using System.IO;
using ToDoApi.Interfaces;namespace ToDoApi
{public class Startup{public Startup(IConfiguration configuration){Configuration = configuration;}public IConfiguration Configuration { get; }//添加服务public void ConfigureServices(IServiceCollection services){services.AddMvc();//添加Swagger服务services.AddSwaggerGen(c =>{c.SwaggerDoc("v1", new Info{Version = "v1",Title = "ToDo API",Description = "A simple example ASP.NET Core Web API",TermsOfService = "None",Contact = new Contact { Name = "Shayne Boyer", Email = "", Url = "https://twitter.com/spboyer" },License = new License { Name = "Use under LICX", Url = "https://example.com/license" }});var basePath = PlatformServices.Default.Application.ApplicationBasePath;var xmlPath = Path.Combine(basePath, "ToDoApi.xml");c.IncludeXmlComments(xmlPath);});services.AddSingleton<IToDoRepository, Services.ToDoRepository>();}// 配置服务public void Configure(IApplicationBuilder app, IHostingEnvironment env){app.UseSwagger();//配置Swagger服务app.UseSwaggerUI(c =>{c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");});//配置开发环境if (env.IsDevelopment()){app.UseDeveloperExceptionPage();}app.UseMvc();}}
}
10.4：启动项设置为swagger启动
在launchSettings.json做如下修改
这样你的项目用IIS Express启动来就是swagger界面
11：最终效果
11.2：测试获取数据的方法
12:对NetCore的理解还很浅，只是做了一个简单的demo希望能帮到你，只是写了mysql的，如果是要用SqlServer,则修改读取SqlServerConnection的数据连接然后把数据仓储里面的 MySql.Data.MySqlClien改成Sql server的就可以了
13：demo连接：
https://files.cnblogs.com/files/gouguo/ToDoApi.rar
