localhost is currently unable to handle this request. In ASP.NET controller for retrieving data from dbContext

I am using dbContext instance to retrieve all data in the view of asp.net but ending up with this error

> This page isn't working - localhost is currently unable to handle this request. HTTP ERROR 500.

I have a record in the database and unable to retrieve it.

This is my method to retrieve all data

private readonly DataContext db;

public PatientsData(DataContext _db) {
    db = _db;
}

public IEnumerable<Patients> GetAllPatients() 
{
    var patients = db.Patients.ToList();
    return patients;
}

This is my dbContext:

public class DataContext : DbContext
{
    //private readonly IConfiguration Configuration;

    public DataContext(DbContextOptions<DataContext> options)
        : base(options)
    {
    }
       
    public DbSet<Patients> Patients { get; set; }
} 

This is my view

@model V._3._0.Models.PatientsData
<table>
    @foreach(var patients in Model.GetAllPatients())
    {
        <tr>
            <td>@patients.Id.</td>
            <td>@patients.Name</td>
            <td>@patients.Status</td>
            <td>@patients.DateOfAdm</td>
            <td>@patients.DateOfDis</td>
            
        </tr>
    }
</table> 

I am unable to spot where I am going wrong ...

> This page isn't working - localhost is currently unable to handle this
> request. HTTP ERROR 500.

The information you have shared is not adequate regarding the error you are getting. Even not sure if you have any additional configuration on IIS or browser link or anything.

However, I found some inconsistency within your share code which may not function as expected.

Let's check how we can get th patient list and in order to do that, what part of your code need to improve.

Assuming you have following model:

public class Patients
    {
        [Key]
        public int Id { get; set; }
        public string Name { get; set; }
        public string Status {get; set; }
        public DateTime DateOfAdm { get; set; }
        public DateTime DateOfDis { get; set; }
    }

1. Incorrect action in controller:

You are trying to display list of patient within view but you are using IEnumerable<Patients> yet not returning view instead you are just doing return patients; which certainly wouldn't generate view html.

You should fix it as following:

public ActionResult GetAllPatients()
        {
            var patients = db.Patients.ToList();
            return View(patients);
        }

Incorrect model reference in view:

You are using this @model V._3._0.Models.PatientsData reference within your view but you are returning Patients.ToList() which should be type of Patients class. Thus, your reference should be :

@model IEnumerable<YourProjectName.Models.Patients>

Wrong foreeach loop invocation:

As your controller sending IEnumerable<Patients> and @model reference would contain that, you don't need to call Model.GetAllPatients() and you cannot, this is incorrct syntax.

Instead you should write as following:

@model IEnumerable<DotNet6MVCWebApp.Models.Patients>
<table>
    @foreach (var patients in Model)
    {
        <tr>
            <td>@patients.Id.</td>
            <td>@patients.Name</td>
            <td>@patients.Status</td>
            <td>@patients.DateOfAdm</td>
            <td>@patients.DateOfDis</td>

        </tr>
    }
</table> 

Output:

Note: If you would like to know more details on how can we load data in view you could check our official document here