I have a course entity which has an ICollection<CourseTrainer>.
public class CourseTrainer : FullAuditedEntity
{
public int CourseId { get; set; }
public Course Course { get; set; }
public int TrainerId { get; set; }
public Trainer Trainer { get; set; }
public virtual bool IsSignedOff { get; set; }
public virtual DateTime? SignedOffDate { get; set; }
}
Initally I was deleting everything and then inserting everything when the user clicks save. This resulted in the record becoming IsDeleted=1 for every save and if no changes were made to the courseTrainer then the same record would be re-inserted after. This plays havok with the audit logs and makes them less readable (because if there are a lot of trainers then every time the main course is saved there would be loads of course trainer changes)
I then tried this code which works however the IsDeleted not being updated - instead, the record is deleted.
var toInsert = courseInputEntity.UserCourses.Except(savedCourse.UserCourses).ToList();
var toRemove = savedCourse.UserCourses.Except(courseInputEntity.UserCourses).ToList();
await _courseUserRepository.DeleteAsync(cu => toRemove.Any(t => t.Id == cu.UserId));
foreach (var trainee in toInsert)
{
await _courseUserRepository.InsertAsync(trainee);
}
2 Answer(s)
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0
Hi,
- is _courseUserRepository operates on CourseTrainer entity ?
- Does that work if you delete records using foreach loop and using await _courseUserRepository.DeleteAsync(id) ?
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0
Hi ismcagdas, thanks for getting back to me. I updated the CourseTrainer entity to include
public bool Equals(CourseTrainer other) { if (ReferenceEquals(other, null)) { return false; } if (ReferenceEquals(this, other)) { return true; } return CourseId.Equals(other.CourseId) && TrainerId.Equals(other.TrainerId); } public override int GetHashCode() { int hashCourseId = CourseId.GetHashCode(); int hashTrainerId = TrainerId.GetHashCode(); return hashCourseId ^ hashTrainerId; }With the above I was then able to use the Except keyword
private async Task UpdateCourseTrainers(Course courseInputEntity, Course savedCourse) { var toRemove = savedCourse.CourseTrainers.Except(courseInputEntity.CourseTrainers).ToList(); await _courseTrainerRepository.DeleteAsync(ct => toRemove.Any(t => t.TrainerId == ct.TrainerId)); var toInsert = courseInputEntity.CourseTrainers.Except(savedCourse.CourseTrainers).ToList(); foreach (var trainer in toInsert) { await _courseTrainerRepository.InsertAsync(trainer); } }It works well now
