Continuation of Creating and Displaying N to N Relationships part 2
First let’s look at what we want to display in our View
This is what a typical grade sheet displaying the many:many relationship between students and grades would look like – so how do we do this?
First I am going to Create a new View – simply right click, Add View – and set the options
Now I am going to first do this the simplest method – use of the ViewBag, I first need a controller – and I will add the Controller method to the GradesController – which of course must be named to match the View “ViewAsTable”. I am also going to add to the ViewBag all the elements I need to create the display
Add the following method to your GradesController
public ActionResult ViewAsTable()
{
ViewBag.ClassId = new List<Class>(db.Classes);
ViewBag.StudentId = new List<Student>(db.Students);
ViewBag.GradeId = new List<Grade>(db.Grades);
return View();
} Next I will create the code to display in the View. Note the use of the foreach loops – one for the header (to display classes) and the 2 embedded loops to display students and grades.
ViewAsTable.cshtml
@model SampleNtoN.Models.Grade
@{
ViewBag.Title = "View As Table";
}
<h2>View As Table</h2>
<table class="table">
<tr>
<th></th>
@foreach (var c in ViewBag.ClassId)
{
<th>@c.ClassName</th>
}
</tr>
@foreach (var s in ViewBag.StudentId)
{
<tr>
<td>
@s.StudentName
</td>
@foreach (var c in ViewBag.ClassId)
{
<td>
@foreach (var g in ViewBag.Gradeid)
{
if((g.StudentId == s.StudentId)&&(g.ClassId==c.ClassId))
{
@g.Grade1
}
}
</td>
}
</tr>
}
</table>Some good references – there are quite a few ways to do this and I am only demonstrating what I see as the simplest of the solutions.
https://www.codeproject.com/Articles/1110431/Gridview-in-ASP-NET-MVC