CODEWITHSUNDEEP
asp.net-coreentity-framework-core
Thinker
Thinker

Reputation: 5356

Create child without parent using EntityFramework Core

In my ASP.Net core (1.1) Web API I have two models: Task and Feature. Initially I create one or many Tasks and then I can combine few of them to be a Feature.

For this I have written my models as following:

public class User_Task
{
    [Key]
    public long TaskId { get; set; }
    public string What { get; set; }

    [ForeignKey("FeatureId")]
    public long FeatureId { get; set; }

    public User_Task()
    {

    }

}

and Feature:

public class Feature
{
    [Key]
    public long FeatureId { get; set; }
    public string Analyst_comment { get; set; }

    public virtual ICollection<User_Task> Tasks { get; set; }

    public Feature()
    {

    }
}

Now the problem is: I am not being able to create a task without first creating a Feature- I tried passing featureId as 0 or null for POST request of Tasks but it fails (for null I get bad request and for 0 it throws exception).

What should I modify in my models or controller or repo class to handle this situation?

Upvotes: 0

Views: 180

Answers (1)

Tseng
Tseng

Reputation: 64150

You have to make your FeatureId nullable. 

public class User_Task
{
    [Key]
    public long TaskId { get; set; }
    public string What { get; set; }

    [ForeignKey("FeatureId")]
    public long? FeatureId { get; set; }
}

then add and run an migration, EF Core should be able to figure out it's an optional one-to-many relationship.

Upvotes: 3

Related Questions