What is the correct way to find all child entities, remove the association to the parent, and delete them?

manpreet Best Answer 2 years ago

I need to update a record that has child entities. The update action needs to clear references to the child and then cascade delete existing child entities.

I have the object Id and query for the record but the child entity ID is either incorrect or produces duplicates with incomplete data.

The Models:

LcReport.cs

public class LcReport
{
    [Key]
    public int Id { get; set; }
    public string Ou { get; set; }
    public string CourseName { get; set; }
    public DateTime DateTimeSubmittedUtc { get; set; }
    public bool ReportCompleted { get; set; }
    public string Status { get; set; }
    public ICollection<LcModule> Modules { get; set; }
}

LcModule.cs

public class LcModule
{
    [Key]
    public int Id { get; set; }
    public string ModuleId { get; set; }
    public string Title { get; set; }
    public ICollection<LcTopic> Topics { get; set; }
}

LcTopic.cs

public class LcTopic
{
    [Key]
    public int Id { get; set; }
    public int TopicId { get; set; }
    public string Title { get; set; }
    public string Url { get; set; }
    public int StatusCode { get; set; }
    public string StatusDescription { get; set; }
    public ICollection<LcTopicLink> Links { get; set; }
}

LcTopicLinks.cs

public class LcTopicLink
{
    [Key]
    public int Id { get; set; }
    public string Url {