Virtual Entity:
1) You have data in another system that only needs to be viewed in Dynamics 365
2) Highly sensitive data in an external system that you don’t want to be stored In Dynamics 365
Virtual Entities are an alternative to client-side and server-side approaches for connecting external data with Dynamics 365 with a solution that is significantly easier to configure and manage.
As the name itself states the "Virtual", which is not physically exists.
The Virtual entity is quite useful in integrations scenario's like Microsoft Dynamics 365 Integration with a third party system.
Where the data from third party system will not be stored physically on Dynamics 365 database to avoid data replication.
The data will be "read only" with the first release of this new feature.
User can not update the data on the virtual entity but can be used in dashboard, viewed in advanced finds, views, query purposes only.
Can not run the workflows or business process flows on the virtual entity. Hopefully in next releases more functionality will be added to virtual entity.
例如：从第三方提供的接口中获取数据
第三方服务： https://services.odata.org/V4/OData/OData.svc/
效果：把第三方服务的数据通过虚拟实体放到Dynamics CRM Online
1.Create Data Source
创建完成之后，保存
2.Create Virtual Entity
- 显示名称：Advertisement；复数名称为：Advertisements
- 数据源选择：创建的数据源 Public Service
- 外部名称必须为：Advertisement 外部集合名称必须为：Advertisements
创建字段
将虚拟实体的字段和第三方系统的外部字段一一对应起来(Virtual Entity field mapping)
创建完成之后，保存并且发布
就可以在虚拟实体中看到第三方数据源的数据
Virtual Entity Considerations
- 数据只读
- 虚拟实体只能创建为组织所有
- 虚拟实体不支持货币类型
- 虚拟实体字段不能计算
- 每次进入到虚拟实体的时候，都需要从第三方系统加载数据，比较缓慢
参考博客：
https://blogs.technet.microsoft.com/lystavlen/2017/09/08/virtual-entities/