.NetCore学习笔记：一、UnitOfWork工作单元

Maintains a list of objects affected by a business transaction and coordinates the writing out of changes and the resolution of concurrency problems.

　　Unit of Work --Martin Fowler

Unit Of Work模式，由马丁大叔提出，是一种数据访问模式。UOW模式的作用是在业务用例的操作中跟踪对象的所有更改（增加、删除和更新），并将所有更改的对象保存在其维护的列表中。在业务用例的终点，通过事务，一次性提交所有更改，以确保数据的完整性和有效性。总而言之，UOW协调这些对象的持久化及并发问题。

定义工作单元接口：

 /// <summary>
 /// 工作单元接口
 /// </summary>
 public interface IUnitOfWork : IDisposable
 {
     /// <summary>
     /// 事务
     /// </summary>
     IDbTransaction DbTransaction { get; }
     /// <summary>
     /// 数据连接
     /// </summary>
     IDbConnection DbConnection { get; }

     /// <summary>
     /// 开启事务
     /// </summary>
     void BeginTransaction();
     /// <summary>
     /// 完成事务
     /// </summary>
     void Commit();
     /// <summary>
     /// 回滚事务
     /// </summary>
     void Rollback();
 }

实现工作单元：

 /// <summary>
 /// 工作单元
 /// </summary>
 public class UnitOfWork : IUnitOfWork
 {
     private bool _disposed;
     private IDbTransaction _trans = null;
     /// <summary>
     /// 事务
     /// </summary>
     public IDbTransaction DbTransaction { get { return _trans; } }

     private IDbConnection _connection;
     /// <summary>
     /// 数据连接
     /// </summary>
     public IDbConnection DbConnection { get { return _connection; } }

     public UnitOfWork(IConfiguration configuration)
     {
         var connectionString = configuration.GetConnectionString("SqlConnection");
         _connection = new MySqlConnection(connectionString); //这里使用的mysql
         _connection.Open();
     }

     /// <summary>
     /// 开启事务
     /// </summary>
     public void BeginTransaction()
     {
         _trans = _connection.BeginTransaction();
     }
     /// <summary>
     /// 完成事务
     /// </summary>
     public void Commit() => _trans?.Commit();
     /// <summary>
     /// 回滚事务
     /// </summary>
     public void Rollback() => _trans?.Rollback();

     public void Dispose()
     {
         Dispose(true);
         GC.SuppressFinalize(this);
     }

     ~UnitOfWork() => Dispose(false);

     protected virtual void Dispose(bool disposing)
     {
         if (_disposed)
             return;
         if (disposing)
         {
             _trans?.Dispose();
             _connection?.Dispose();
         }
         _trans = null;
         _connection = null;
         _disposed = true;
     }
 }

在IServiceCollection容器中注册：

services.AddScoped<IUnitOfWork, UnitOfWork>();

源码地址：https://github.com/letnet/NetCoreDemo