Domain driven design CQR的部门域实体上有哪些属性

我第一次在CQRS试用，需要一些建议

在我的业务中，可以重命名部门。为此，我调度一个重命名的partment命令，由命令处理程序捕获。然后，该处理程序将调用Department实体上的rename方法，如果这对实体有任何作用，即更新name属性？？由于该名称仅用于查看目的，我想我应该做的就是发送一个DepartmentRename事件并更新相应的ViewModels，我的想法正确吗

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提前感谢

CQRS是将读取和写入的责任分为不同部分的地方：

写入存储、事件存储以持久化域中发生的所有事件

读取存储，以持久化从写入模型的事件存储中产生的事件流增量生成的投影

您的操作是正确的，因为

RenameDepartmentCommandHandler

将处理命令

RenameDepartmentCommand

：

public void RenameDepartmentCommandHandler(RenameDepartmentCommand command)
{
    // repository is injected in for us during command handler instantiation
    var dept = this.repository.GetByDeptName(command.DepartmentName);
    dept.RenameDepartment(command.NewDepartmentName);
    this.repository.Save(dept);

    // the repository will save all of the events, once committed
    // a separate piece of code running in the background will
    // listen for new events from the the event-store and dispatch
    // them to anyone who may be listening
}

实际的实体需要在写模型中通过持久化事件来更新，这是唯一的真相来源。您不仅要更新读取模型，还要始终更新写入模型

在写模型持久化事件之后，它将被分派（在将来的某个时间点）到读模型

读模型是写模型的从属模型。因为它是一个从机，所以它最终将是一致的（对于使用独立基础设施且不使用分布式事务的读写模型）。。。最终，一致性并不意味着有问题，通常大多数问题空间都可以接受延迟（10毫秒到秒甚至分钟）

因此，您的实体将如下所示：

public class Department : AggregateBase
{
    // this class derives from jOliver's CommonDomain project
    // only useful if using C# - there will be similar
    // event sourcing infrastructure projects for different
    // languages

    public string Name { get; protected set; }
    // all other properties go here

    public void RenameDepartment(public newName)
    {
        // the DepartmentRenamed is an immutable class taking the
        // current name and new name as constructor parameters          
        RaiseEvent(new DepartmentRenamed(this.Name, newName));
    }

    protected void Apply(DepartmentRenamed evnt)
    {
        this.Name = event.NewName;
    }
}

public class DeptNameListProjection : IEventHandler<DepartmentRenamed>
{
    public void Handle(DepartmentRenamed evntFromEventStore)
    {
        var department = this.readStore.Find(evntFromEventStore.OldName);
        // write it, depends on your infrastructure
        // normally a SqlCommand or similar is fine here, I try and avoid
        // using an ORM as imho flat tables make more sense for read models
    }
}

你的阅读模型投影是这样的：

public class Department : AggregateBase
{
    // this class derives from jOliver's CommonDomain project
    // only useful if using C# - there will be similar
    // event sourcing infrastructure projects for different
    // languages

    public string Name { get; protected set; }
    // all other properties go here

    public void RenameDepartment(public newName)
    {
        // the DepartmentRenamed is an immutable class taking the
        // current name and new name as constructor parameters          
        RaiseEvent(new DepartmentRenamed(this.Name, newName));
    }

    protected void Apply(DepartmentRenamed evnt)
    {
        this.Name = event.NewName;
    }
}

public class DeptNameListProjection : IEventHandler<DepartmentRenamed>
{
    public void Handle(DepartmentRenamed evntFromEventStore)
    {
        var department = this.readStore.Find(evntFromEventStore.OldName);
        // write it, depends on your infrastructure
        // normally a SqlCommand or similar is fine here, I try and avoid
        // using an ORM as imho flat tables make more sense for read models
    }
}

公共类DeptNameListProjection:IEventHandler
{
公共无效句柄（部门重命名为evntFromEventStore）
{
var department=this.readStore.Find（evntFromEventStore.OldName）；
//写它，取决于你的基础设施
//通常情况下，SqlCommand或类似命令在这里很好，我会尽量避免
//使用ORM作为imho平面表对于读取模型更有意义
}
}

谢谢这真的很有帮助：-）