CompanyName ) from another table and adds the necessary JOIN clause to the. So, in other words, it is not recommended to directly reference the database tables from remote Bounded contexts. ORM (object-relational mapping) frameworks really simplify the developers. How can I relate two objects from different contexts together The example below throws the following exception: System. Here, you will learn the new features of querying introduced in Entity. Visit the LINQ-to-Entities chapter to learn more about the basics of querying in Entity Framework. Every time a Person is updated the remote Bounded context publishes an event to all interested Bounded contexts that react to these events and update their local cache. Querying in Entity Framework Core remains the same as in EF 6.x, with more optimized SQL queries and the ability to include C/VB.NET functions into LINQ-to-Entities queries. The best integration technics is to use integration events. They are in general implemented as Value objects. On the app side all db interactions through EF are not working anymore. Some tables of one schema have dependencies on tables that reside on a different schema. I recently organized my tables into 4 different schemas. In TSQL, I can reference them with the DB>user>table structure (, ) to pull the data for comparison. The database used to have one schema, dbo and everything was working fine. ![]() These databases do not have the same schema. You could have for example a scheduled task or cron job that fetches all the Persons and saved them in a local cache as local objects local objects have in general fewer properties as the remote objects and no update logic. I am often comparing data in tables in different databases. One of them is the Anti-corruption layer. Employee or Payer or whatever local domain you have.įor this there are more integration technics. Your collections come from different contexts so get ids of employees first in linq-to-objects: var ids from e1 in thatEmployees join e2 in thisEmployees on e1.EmployeeNumber equals e2.EmployeeNumber select e1.Id Since its in two different contexts try using ToList to get all objects. The Person from the HR Bounded context should not be used as it is in the local Bounded context, but converted to a (simpler) object, named accordingly to the Ubiquitous language from the local Bounded context, i.e. ![]() I have recently blogged about creating database context scope which will make using multiple EF contexts and transactions easier. Entity Framework considers the null ObjectContext to be a different context and therefore won’t allow objects from different contexts to be joined. ![]() The other, which is now attached to the context, returns the ObjectContext instance. Of course this approach will require you to pass this object to methods which update DB. When you detach one entity in the graph, its ObjectContext property evaluates to null. You should translate the object model from remote Bounded contexts to local Bounded context. You can achieve this by passing one Entit圜onnection object to both of your contexts constructors.
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