I have a forum of this model:
Topic
- Id
- Title
- Text
- LastMessageId (nullable)
Message
- Id
- Text
- TopicId
I need to populate a data table in Framework Core 2.1 with default values using the OnModelCreating in the ApplicationDbContext using the _builder.Entity<>().HasData function.
But there is a problem.
In the topic there are messages. Each message belongs to one topic. But the topic also has a record of the last message LastMessageId .
When I try to fill in the test data, the error crashes:
It was a message that was saved: 'Topic [Added] <- Messages Topic {' TopicId '} Message [Added] <- LastMessage {' LastMessageId '} Topic [Added]
at at Microsoft.EntityFrameworkCore.Internal.Multigraph`2.ThrowCycle ...
It is clear that the cycle is that the message has a parent topic, and the topic has the last message.
How to fill in such data?
