Comparing two lists in C# ASP.NET MVC LINQ Entity Framework

Question

As the title says, im trying to compare the stamped in datetime and stamped out datetime.

I have a flex variable which shall get the value of the difference between those two dates in a workday (8h).

"If I stamp in 08:00 and stamp out 17:00, my flex shall be +1(h)"

Model:

public class FlexModel
{
    public List<User> Users { get; set; }
    public List<Stamping> Stampings { get; set; } 
    public decimal FlexTime { get; set; }
}

public partial class Stamping
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    [Required]
    public int UserId { get; set; }

    [Required]
    [DataType(DataType.DateTime)]
    public DateTime Timestamp { get; set; }

    [Required]
    [StringLength(3)]
    public string StampingType { get; set; }

    public virtual User User { get; set; }
}

View:

@Html.LabelFor(model => model.FlexTime, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
    @Html.DisplayFor(model => model.FlexTime, new { htmlAttributes = new { @class = "form-control" } })
    @Html.ValidationMessageFor(model => model.FlexTime, "", new { @class = "text-danger" })
</div>

Controller:

public ActionResult Info()
{
    var flexModel = new FlexModel();
    var userId = (int)Session["userId"];
    var user = _db.Users.Find(userId);
    var stampIn = _db.Stampings
                     .Where(i => i.StampingType == "in")
                     .Where(i => i.User == user)
                     .ToList();

    var stampOut = _db.Stampings
                      .Where(i => i.StampingType == "out")
                      .Where(i => i.User == user)
                      .ToList();

    var workDay = 8;

    if (stampIn.Count == 0)
    {
        return View();
    }

    foreach (var itemIn in stampIn)
    {
        //Dont know what to do here
    }

    foreach (var itemOut in stampOut)
    {
        //Dont know what to do here either
    }

    return View();
}

Please help.

your class implementation not looks fine to me add in the class TimeOut and TimeIn both if TimeOut is null and TimeIn not null is TimeIn if nboth then it is TimeOut — Ehsan Sajjad
– Ehsan Sajjad, Commented Oct 3, 2014 at 13:00
That doesnt really help me do the calculation sir... I need to know how to compare these two lists to each other, through the hours of it. — Qvadriologic
– Qvadriologic, Commented Oct 3, 2014 at 13:01
in both list how will you relate timein and timout of user think about it — Ehsan Sajjad
– Ehsan Sajjad, Commented Oct 3, 2014 at 13:02

DavidG · Accepted Answer · 2014-10-03 14:59:49Z

1

You can correlate the lists like this:

var attendance = from sin in stampIn
                 select new 
                 {
                    StampIn = sin,
                    StampOut = stampOut.FirstOrDefault(sout => 
                                    sout.Timestamp > sin.Timestamp)
                 };

That gives you a list of stampin vs stampout events (though the stamp out may be null). Then you need to calculate the flexitime like this:

var flexitime = from att in attendance
                select new
                {
                    TimeIn = att.StampIn.Timestamp,
                    TimeOut = att.StampOut == null ? (DateTime?)null : att.StampOut.Timestamp,
                    TotalTime = att.StampOut == null ? 0 :  
                        att.StampOut.Timestamp.Subtract(att.StampIn.Timestamp).TotalHours
                };

You can now convert this to your FlexModel object (I'll only fill in the FlexTime property as I'm not sure how/why you need the others):

var workDay = 8;
var flexModel = new FlexModel 
{
    FlexTime = Convert.ToDecimal(flexitime
                   .Sum(f => f.TotalTime - workDay))
};
return View(flexModel);

edited Oct 3, 2014 at 14:59

answered Oct 3, 2014 at 13:03

DavidG

120k13 gold badges232 silver badges239 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Qvadriologic Over a year ago

Im sorry, but the result does not work. I need more specific detail of how to use these variables please...

Qvadriologic Over a year ago

Well, the flex value still shows 0 in the View... Im not quite sure why the calculate wont work!

Qvadriologic Over a year ago

FlexTime = flexitime.Sum(f => f.TotalTime) - "Cannot convert source type 'double' to target 'decimal'

Qvadriologic Over a year ago

Yes Ok, it works. But the problem now is that it adds up no matter what time the user stamp in or out. It has to be more than 8 hours to add, only then should it use the difference. And ofcourse vice versa if it's less than 8 hours for that day...

Collectives™ on Stack Overflow

Comparing two lists in C# ASP.NET MVC LINQ Entity Framework

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related