C#•10mo ago

✅ MySQL with Entity Framework, getting null of entity all time

public class UserAssignmentDate
{
    [ForeignKey("UserId")]
    public int UserId { get; set; }

    [ForeignKey("AssignmentId")]
    public int AssignmentId { get; set; }
    
    public DateTimeOffset AssignmentTime { get; set; }
    public DateTimeOffset DeadLineDateTime { get; set; }
    public DateTimeOffset LastUploadDateTime { get; set; }
    public TimeSpan TimeToNextUpload { get; set; }

    // Navigation properties
    public User User { get; set; }
    public Assignment Assignment { get; set; }
}

public class UserAssignmentDate
{
    [ForeignKey("UserId")]
    public int UserId { get; set; }

    [ForeignKey("AssignmentId")]
    public int AssignmentId { get; set; }
    
    public DateTimeOffset AssignmentTime { get; set; }
    public DateTimeOffset DeadLineDateTime { get; set; }
    public DateTimeOffset LastUploadDateTime { get; set; }
    public TimeSpan TimeToNextUpload { get; set; }

    // Navigation properties
    public User User { get; set; }
    public Assignment Assignment { get; set; }
}

            var userAssignmentDate = await dbContext.UserAssignmentDates
                .FirstOrDefaultAsync(userAssignmentDate => userAssignmentDate.UserId == UserId && userAssignmentDate.AssignmentId == assignmentId);

            var userAssignmentDate = await dbContext.UserAssignmentDates
                .FirstOrDefaultAsync(userAssignmentDate => userAssignmentDate.UserId == UserId && userAssignmentDate.AssignmentId == assignmentId);

        foreach (int userId in userIds)
        {
            var userAssignmentDate = new UserAssignmentDate
            {
                UserId = userId,
                AssignmentId = assignmentId,
                AssignmentTime = assignmentTime,
                LastUploadDateTime = DateTimeOffset.MinValue,
            };

            dbContext.UserAssignmentDates.Add(userAssignmentDate);
        }
        
        await dbContext.SaveChangesAsync();

        foreach (int userId in userIds)
        {
            var userAssignmentDate = new UserAssignmentDate
            {
                UserId = userId,
                AssignmentId = assignmentId,
                AssignmentTime = assignmentTime,
                LastUploadDateTime = DateTimeOffset.MinValue,
            };

            dbContext.UserAssignmentDates.Add(userAssignmentDate);
        }
        
        await dbContext.SaveChangesAsync();

and userAssignmentDate returns null all time when UserId and AssignmentId are good values

13 Replies

Angius•10mo ago

You need to explicitly load the related data with .Include() Or better, .Select()

WhiteboyOP•10mo ago

            var userAssignmentDate = await dbContext.UserAssignmentDates
                .Include(ua => ua.User)
                .Include(ua => ua.Assignment)
                .Where(assignmentDate => assignmentDate.UserId == UserId && assignmentDate.AssignmentId == assignmentId)
                .FirstOrDefaultAsync();

            if (userAssignmentDate != null)
            {
                userAssignmentDate.LastUploadDateTime = DateTimeOffset.Now;
                await dbContext.SaveChangesAsync();
            }

            var userAssignmentDate = await dbContext.UserAssignmentDates
                .Include(ua => ua.User)
                .Include(ua => ua.Assignment)
                .Where(assignmentDate => assignmentDate.UserId == UserId && assignmentDate.AssignmentId == assignmentId)
                .FirstOrDefaultAsync();

            if (userAssignmentDate != null)
            {
                userAssignmentDate.LastUploadDateTime = DateTimeOffset.Now;
                await dbContext.SaveChangesAsync();
            }

so now it's not null but the time is not updating D:

        private void GetUserTaskRemainingTime(int assignmentId)
        {
            var userAssignmentDate = dbContext.UserAssignmentDates.FirstOrDefault(userAssignmentDate => userAssignmentDate.AssignmentId == assignmentId && userAssignmentDate.UserId == UserId);
            if (userAssignmentDate == null || Assignment == null) return;
                
            RemainingTimeToDoAssignment = userAssignmentDate.DeadLineDateTime - DateTimeOffset.Now;
            if (userAssignmentDate.LastUploadDateTime == DateTimeOffset.MinValue)
            {
                TimeToNextUpload = TimeSpan.Zero;
            }
            else
            {
                TimeToNextUpload = userAssignmentDate.LastUploadDateTime + Assignment.UploadFrequency - DateTimeOffset.Now;
            }
        }

        private void GetUserTaskRemainingTime(int assignmentId)
        {
            var userAssignmentDate = dbContext.UserAssignmentDates.FirstOrDefault(userAssignmentDate => userAssignmentDate.AssignmentId == assignmentId && userAssignmentDate.UserId == UserId);
            if (userAssignmentDate == null || Assignment == null) return;
                
            RemainingTimeToDoAssignment = userAssignmentDate.DeadLineDateTime - DateTimeOffset.Now;
            if (userAssignmentDate.LastUploadDateTime == DateTimeOffset.MinValue)
            {
                TimeToNextUpload = TimeSpan.Zero;
            }
            else
            {
                TimeToNextUpload = userAssignmentDate.LastUploadDateTime + Assignment.UploadFrequency - DateTimeOffset.Now;
            }
        }

cs     
var userAssignmentDate = await dbContext.UserAssignmentDates
                .Include(ua => ua.User)
                .Include(ua => ua.Assignment)
                .Where(assignmentDate => assignmentDate.UserId == UserId && assignmentDate.AssignmentId == assignmentId)
                .FirstOrDefaultAsync();

            if (userAssignmentDate != null)
            {
                userAssignmentDate.LastUploadDateTime = DateTimeOffset.Now;
                await dbContext.SaveChangesAsync();
            }
            
            await dbContext.SaveChangesAsync();

            PageHelper.SetTempDataSuccessMessage($"last up time: {userAssignmentDate.LastUploadDateTime}.", TempData);
            return await Task.FromResult<IActionResult>(RedirectToPage("/AssignmentView", new
            {
                assignment.AssignmentId,
            }));

cs     
var userAssignmentDate = await dbContext.UserAssignmentDates
                .Include(ua => ua.User)
                .Include(ua => ua.Assignment)
                .Where(assignmentDate => assignmentDate.UserId == UserId && assignmentDate.AssignmentId == assignmentId)
                .FirstOrDefaultAsync();

            if (userAssignmentDate != null)
            {
                userAssignmentDate.LastUploadDateTime = DateTimeOffset.Now;
                await dbContext.SaveChangesAsync();
            }
            
            await dbContext.SaveChangesAsync();

            PageHelper.SetTempDataSuccessMessage($"last up time: {userAssignmentDate.LastUploadDateTime}.", TempData);
            return await Task.FromResult<IActionResult>(RedirectToPage("/AssignmentView", new
            {
                assignment.AssignmentId,
            }));

How is it null when i wanna chcek value?? @ZZZZZZZZZZZZZZZZZZZZZZZZZ

Angius•10mo ago

Where is it null, exactly?

WhiteboyOP•10mo ago

PageHelper.SetTempDataSuccessMessage($"last up time: {userAssignmentDate.LastUploadDateTime}.", TempData);

PageHelper.SetTempDataSuccessMessage($"last up time: {userAssignmentDate.LastUploadDateTime}.", TempData);

here

Angius•10mo ago

And the whole assignment is null, or just the upload date?

WhiteboyOP•10mo ago

WhiteboyOP•10mo ago

Angius•10mo ago

Well, apparently there's no such assignment Try commenting out the Where() clause, see if that gives results

WhiteboyOP•10mo ago

idk there seen to be 6 results but for some reason i can't get to them

Angius•10mo ago

Make sure that UserId and assignmentId are both 1, for example Since I can see you have an entry like that Issue seems to be with what you're trying to query by

WhiteboyOP•10mo ago

im gonna lose my mind getting this project to very end ... the issue was with passing userId = 0 which obviously doesn't exist So i just get correct userId and it works just fine

Gaming

Programming

✅ MySQL with Entity Framework, getting null of entity all time